Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E34 (1989 - 1995)

E34 (1989 - 1995)

Reply
 
Thread Tools Display Modes
  #1  
Old 10-27-2012, 04:44 PM
S406 S406 is offline
Registered User
Location: Montana
 
Join Date: Oct 2012
Posts: 68
Mein Auto: 00 S4, 93 525i
cooling system issues

So My upper rad hose sprung a leak and I replaced it. The coolant got low enough to where the heater blew cold air. Everything worked fine before the hose issue. Now its wanting to overheat and I have no heat any longer, I tried bleeding the system via the bled screw on top the rad. It blows steam. Am i looking at air lock? Could my thermostat of failed? What is the electrical plug for on the bottom drivers side of the rad? Im use to audis so this bmw crap is all new to me...Not getting coolant into upper rad hose...Thermostat??

Last edited by S406; 10-27-2012 at 04:52 PM.
Reply With Quote
Advertisement
  #2  
Old 10-27-2012, 05:43 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
1. The electrical plug at the bottom that you referred to is a low coolant sensor.
2. To bleed your radiator, you need to set your cabin heaters to maximum hot at maximum blower setting, and bring your radiator to operating temperature. Then bleed like your normally do, close the bleed screw, top up to the top of your expansion tank and screw the rad cap down tight.
3. If that doesn't fix your problem, check everywhere for leaks. Dump in some bright, strong smelling cheap coolant. It will mix ok with your oem coolant and it will make it easier to spot and localise smaller leaks.
4. No coolant in your upper radiator hose means the thermostat is totally closed, as even with a busted water pump your upper radiator hose will get hot through convection if the thermostat opens properly.
5. Most overheating problems with the E34 are due to either or both of the thermostat and the water pump. I would advise you to change both anyway without bothering for a diagnosis. Both will fail eventually. It will be a waste of time to wait.
6. Please change the rad cap and bleed screw too...$15 total for both and good peace of mind.
7. Check your fuse box to ensure that the aux fan's fuses are working. Jump the aux fan's temp sensor switch to check if the fan itself is working.
8. Google for the E34 Bentley manual and download it and read up its exhaustive troubleshooting list on overheating issues.
9. There have been some recent threads on overheating engines. They should still be on page 1. It would be useful for you to read through them.
10. Read the stickies at the top of these forums for more insights into your issue.
11. Try not to insult the brand out of sheer frustration for mechanical issues that are common to all cars. Having said that, please criticise the brand where justified.

12. Be zen as you go about checking this out, if not you'll end up making unforced errors. No pressure, no pressure.

Last edited by robertobaggio20; 10-27-2012 at 06:02 PM.
Reply With Quote
  #3  
Old 10-27-2012, 08:00 PM
luckydog's Avatar
luckydog luckydog is offline
Lucky to drive a BMW
Location: Ca
 
Join Date: Nov 2010
Posts: 1,356
Mein Auto: 2006 M5///
That sounds like trapped air in the block.It can be difficult to remove . the circulation is not strong enough to clear the trapped air. I had to remove the thermostat on mine for better flow and to clear out the air in the system.You will know when its correct when the center of your rad is warm.Research the e34 threads here for more advise on bleeding air.

Last edited by luckydog; 10-27-2012 at 08:03 PM.
Reply With Quote
  #4  
Old 10-28-2012, 03:21 AM
BMWFatherFigure's Avatar
BMWFatherFigure BMWFatherFigure is offline
Old School
Location: Perth, Western Australia
 
Join Date: Aug 2012
Posts: 2,311
Mein Auto: E23;E30;E38;E32;E34 +
Bleed, bleed, bleed and bleed. I use distilled water to start with and only add coolant when all is good. Start with cold engine and heater full on.
__________________
Good - Fast - Cheap: Pick any two.
Current:
E23 735i; E32 735iL (X 2 - 1 Alpine White and 1 Glacier Blue); E34 535i; E38 735iL; R50 Cooper; R55 Cooper Clubman.
Previous:
E21 318i; E30 318i; E32 735iL; E34 535i; E38 730iL; E53 4.4i
Reply With Quote
  #5  
Old 10-28-2012, 07:29 AM
snowsled7 snowsled7 is offline
The Ornery Old Man
Location: SW Mountains
 
Join Date: Mar 2012
Posts: 980
Mein Auto: GTI
Quote:
Originally Posted by robertobaggio20 View Post
1. The electrical plug at the bottom that you referred to is a low coolant sensor.
I think the low coolant sensore is on the high side of the system in the resevior tank. My radiator doesn't have a sensor in it though

Quote:
2. To bleed your radiator, you need to set your cabin heaters to maximum hot at maximum blower setting, and bring your radiator to operating temperature. Then bleed like your normally do, close the bleed screw, top up to the top of your expansion tank and screw the rad cap down tight.
You do not need to run the blower full speed. This will actually cause the warm up process to take longer. Just set the temp to high.

Quote:
3. If that doesn't fix your problem, check everywhere for leaks. Dump in some bright, strong smelling cheap coolant. It will mix ok with your oem coolant and it will make it easier to spot and localise smaller leaks.
Bobby does not know enough about chemistry to make this reccomendation. Most folks would not mix coolants, I wouldn't if I could help it. If temps allow, just ad water for now until you have solved the problem. Otherwise I would try to stay with the same coolant that is currently in the car.

Quote:
4. No coolant in your upper radiator hose means the thermostat is totally closed, as even with a busted water pump your upper radiator hose will get hot through convection if the thermostat opens properly.
5. Most overheating problems with the E34 are due to either or both of the thermostat and the water pump. I would advise you to change both anyway without bothering for a diagnosis. Both will fail eventually. It will be a waste of time to wait.
Yeah, just do it, it will feel zen

It will be a waste of money to just replace parts for the sake of doing so. I completely agree with bleed, bleed, bleed, as a first course of action, rather than making a parts store run.

Quote:
6. Please change the rad cap and bleed screw too...$15 total for both and good peace of mind.
7. Check your fuse box to ensure that the aux fan's fuses are working. Jump the aux fan's temp sensor switch to check if the fan itself is working.
8. Google for the E34 Bentley manual and download it and read up its exhaustive troubleshooting list on overheating issues.
9. There have been some recent threads on overheating engines. They should still be on page 1. It would be useful for you to read through them.
10. Read the stickies at the top of these forums for more insights into your issue.
11. Try not to insult the brand out of sheer frustration for mechanical issues that are common to all cars. Having said that, please criticise the brand where justified.

12. Be zen as you go about checking this out, if not you'll end up making unforced errors. No pressure, no pressure.

The Bently manual is a good resource, so is this forum, unless of course you follow young bobby's advice. Much of it is a bit dubious as you can see. Regardless of his enthusiasm, he really is very in experienced and I would take his advice with a grain of salt.
__________________
Current ride... '13 GTI Wolfsburg
BMW's from my past...
'92 535i/5 '89 325ix/5
'98 750iL '86 325(e)/5
'95 740iL '84 318i/5
Reply With Quote
  #6  
Old 10-28-2012, 08:23 AM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Quote:
Originally Posted by S406 View Post
So My upper rad hose sprung a leak and I replaced it. The coolant got low enough to where the heater blew cold air. Everything worked fine before the hose issue. Now its wanting to overheat and I have no heat any longer, I tried bleeding the system via the bled screw on top the rad. It blows steam. Am i looking at air lock? Could my thermostat of failed? What is the electrical plug for on the bottom drivers side of the rad? Im use to audis so this bmw crap is all new to me...Not getting coolant into upper rad hose...Thermostat??
If you're talking about #13 on this diagram :

http://www.realoem.com/bmw/showparts...01&hg=17&fg=05

...I believe its the low coolant warning switch.

Oh, did I say that already ? Sorry.
Reply With Quote
  #7  
Old 10-29-2012, 04:46 AM
snowsled7 snowsled7 is offline
The Ornery Old Man
Location: SW Mountains
 
Join Date: Mar 2012
Posts: 980
Mein Auto: GTI
Quote:
Originally Posted by robertobaggio20 View Post
If you're talking about #13 on this diagram :

http://www.realoem.com/bmw/showparts...01&hg=17&fg=05

...I believe its the low coolant warning switch.

Oh, did I say that already ? Sorry.
I do not have the same low end model as you bobby. My e34 has the sensor in the res tank, as I mentioned. If you READ my post I mention that in there
__________________
Current ride... '13 GTI Wolfsburg
BMW's from my past...
'92 535i/5 '89 325ix/5
'98 750iL '86 325(e)/5
'95 740iL '84 318i/5
Reply With Quote
  #8  
Old 10-31-2012, 08:23 AM
S406 S406 is offline
Registered User
Location: Montana
 
Join Date: Oct 2012
Posts: 68
Mein Auto: 00 S4, 93 525i
Holy mother of god what a hassle to bleed the air out! Simple hose replacement took over an hour....Thanks for the tips guys.
Reply With Quote
  #9  
Old 10-31-2012, 01:38 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Quote:
Originally Posted by S406 View Post
Holy mother of god what a hassle to bleed the air out! Simple hose replacement took over an hour....Thanks for the tips guys.
I've never had any difficulty bleeding the air out. I don't know why people struggle with this.

The key things seem to be to set your cabin heat to high (the blower need not be on), and to run your engine up to optemp while at idle, before commencing bleeding. Once you're reached optemp, bleeding will only take 5 minutes.

There will always be a little air in the engine. This is normal and designed for.

If you wish to be really anal, bleed the engine a second time after 2-7 days of regular driving. I used to do this but subsequently realised that it was unnecessary and no longer recommend it.


rgds,
Roberto
Reply With Quote
  #10  
Old 10-31-2012, 04:28 PM
down19992000 down19992000 is offline
Officially Welcomed to the 'Fest
Location: nc
 
Join Date: Feb 2010
Posts: 116
Mein Auto: 1995 525i
Quote:
Originally Posted by robertobaggio20 View Post
I've never had any difficulty bleeding the air out. I don't know why people struggle with this.

The key things seem to be to set your cabin heat to high (the blower need not be on), and to run your engine up to optemp while at idle, before commencing bleeding. Once you're reached optemp, bleeding will only take 5 minutes.

There will always be a little air in the engine. This is normal and designed for.

If you wish to be really anal, bleed the engine a second time after 2-7 days of regular driving. I used to do this but subsequently realised that it was unnecessary and no longer recommend it.


rgds,
Roberto

I had a heck of a time getting all the air out. I was following the procedure to the letter. I have seen numerous threads where people have had problems bleeding all the air out of the system. I am sure someone is gonna say it is unnecessary but the way I did it that worked for ME because I had messed around and bleed it numerous times without luck is: I let the motor get warm so that the thermostat was open and heated water on the stove. I took the upper radiator hose loose (with the engine off and after it had gotten warm enough for the thermostat to open) and dumped the hot water down it. After doing this and topping off with antifreeze my temperature stayed exactly as it should. I will repeat this way worked for ME. It was the only way that I could get all the air out of the system. Apparently there was an air pocket in there that prevented the water pump from priming and pumping coolant through the system. I am not saying that you have to do it this way, only that after bleeding the air out numerous times and having the car still start to get hot when I would try to drive it this was the only way that I could get that air pocket out. I even tried jacking the front of the car up as was advised on an old thread here and this was how I had to do it.

Last edited by down19992000; 10-31-2012 at 04:36 PM.
Reply With Quote
  #11  
Old 10-31-2012, 05:13 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Quote:
Originally Posted by down19992000 View Post
I had a heck of a time getting all the air out. I was following the procedure to the letter. I have seen numerous threads where people have had problems bleeding all the air out of the system. I am sure someone is gonna say it is unnecessary but the way I did it that worked for ME because I had messed around and bleed it numerous times without luck is: I let the motor get warm so that the thermostat was open and heated water on the stove. I took the upper radiator hose loose (with the engine off and after it had gotten warm enough for the thermostat to open) and dumped the hot water down it. After doing this and topping off with antifreeze my temperature stayed exactly as it should. I will repeat this way worked for ME. It was the only way that I could get all the air out of the system. Apparently there was an air pocket in there that prevented the water pump from priming and pumping coolant through the system. I am not saying that you have to do it this way, only that after bleeding the air out numerous times and having the car still start to get hot when I would try to drive it this was the only way that I could get that air pocket out. I even tried jacking the front of the car up as was advised on an old thread here and this was how I had to do it.
Sir, I know that this method worked for you and that the normal method was unsatisfactory. However, the normal method is all that is required. I just changed my radiator over the weekend. I did very simple bleeding...brought her up to optemp, high heat in the cabin and bled. After 45 minutes of driving, I found that coolant levels had drop by 10%, even after the car had become completely cold. This is not normal. So I topped up coolant and attempted to bleed again, but no bubbles came out. I drove and monitored for the next 2 days. Coolant levels gradually dropped like they always do. So the extra drop on the first day was due to something related to changing the entire radiator. That being said, I emphasise again that when I opened the cap and bleed screw a second time and attempted to bleed the car, no bubbles came out.

You clearly had some difficulty bleeding your radiator, but all the extra stuff you did managed to bypass some other problem with your system. That is my opinion. If you've not experienced any further problems with your car, then that problem was minor to begin with, and may possibly have self corrected over time or through some other work that you did.

I've also done all kinds of different bleeding before, including parking the car up on a 30 degree incline. Having done all of it, I can say that the bentley manual's method works, and if it doesn't, something else should be suspected as being wrong.

Sir you should take another look at your car. I suggest that you flush it and bleed it once again (if you haven't done so in awhile). If you can't get most of the bubbles out using the simple method, and need to resort to jacking up the car and using pre-heated coolant or water, then I strongly advise you to look at the car more carefully for other potential issues, in order to arrest further problems that might be in the offing.

Once again, I wish to say that having some air bubbles in the cooling system is normal and designed for by the spooks.


rgds,
Roberto

Last edited by robertobaggio20; 10-31-2012 at 05:16 PM.
Reply With Quote
  #12  
Old 10-31-2012, 05:25 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
If you're doing extra stuff to fix a problem and arrive at the same stuff as others who are doing it just by the basic steps, and the basic steps failed for you, then something has to be different about your situation. There is no other logical conclusion. Please do take another look at your ride.
Reply With Quote
  #13  
Old 10-31-2012, 06:26 PM
down19992000 down19992000 is offline
Officially Welcomed to the 'Fest
Location: nc
 
Join Date: Feb 2010
Posts: 116
Mein Auto: 1995 525i
Quote:
Originally Posted by robertobaggio20 View Post
If you're doing extra stuff to fix a problem and arrive at the same stuff as others who are doing it just by the basic steps, and the basic steps failed for you, then something has to be different about your situation. There is no other logical conclusion. Please do take another look at your ride.
There was and is nothing else wrong with the car other than an air pocket after replacing the radiator. That was well over a year ago. I had gotten a crack in the radiator reservoir. I had to order a replacement and that is where I had a problem getting the air bled out. After doing what I did filling the upper hose with hot water the car never has ran warm again. The only logical conclusion is an air pocket. We have put 12,000 miles on the car since and if the car had another issue it would have showed itself already. Like I said before there have been numerous other threads where people have had problems bleeding the air out of these cars. It's not like I am the first to have a problem. I appreciate your concern but the car is running fine and has been for well over a year. That was the last thing I have done to the car other than oil changes and other routine maintenance. I have spoke to a BMW technician that confirmed that these car are notorious for being hard to get air out of the system if you have to replace one of the cooling components. That's why BMW uses the radiator cap vacuum tool when they do this kind of work.

Last edited by down19992000; 10-31-2012 at 06:30 PM.
Reply With Quote
  #14  
Old 10-31-2012, 06:35 PM
down19992000 down19992000 is offline
Officially Welcomed to the 'Fest
Location: nc
 
Join Date: Feb 2010
Posts: 116
Mein Auto: 1995 525i
Tool for removing air

http://www.amazon.com/UView-550000-A...+to+remove+air

Also Roberto if you don't have a problem like some people do bleeding the air out fine but it's obvious that people do have an issue with it from time to time. That is why I posted what I did to give advice on a tool you can purchase if you have issues or tell them the way I did it. Sorry if you get mad or upset that I was giving my opinion to a poster who had a problem like I did. Don't be afraid to think outside the box and try something different, it helps to do that when owning these cars. I have flushed the cooling system in my truck and wife's minivan along with countless other vehicles and the BMW is the only that has ever gave me a problem.

Last edited by down19992000; 10-31-2012 at 06:52 PM.
Reply With Quote
  #15  
Old 10-31-2012, 06:58 PM
down19992000 down19992000 is offline
Officially Welcomed to the 'Fest
Location: nc
 
Join Date: Feb 2010
Posts: 116
Mein Auto: 1995 525i
http://www.pelicanparts.com/catalog/...TD046_pg35.htm

Pelican parts sells it too and also says that air locks have become prevalent in The cooling systems of today's cars. I believe they know bmws pretty well.
Reply With Quote
  #16  
Old 10-31-2012, 07:47 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Quote:
Originally Posted by down19992000 View Post
http://www.amazon.com/UView-550000-A...+to+remove+air

Also Roberto if you don't have a problem like some people do bleeding the air out fine but it's obvious that people do have an issue with it from time to time. That is why I posted what I did to give advice on a tool you can purchase if you have issues or tell them the way I did it. Sorry if you get mad or upset that I was giving my opinion to a poster who had a problem like I did. Don't be afraid to think outside the box and try something different, it helps to do that when owning these cars. I have flushed the cooling system in my truck and wife's minivan along with countless other vehicles and the BMW is the only that has ever gave me a problem.
Please sir. I've been pondering what you've said for some time (of and on over the years), as I don't want to have a problem that I may be overlooking with my car. I've also pondered the few occasions when others have had issues with bleeding the radiator. I've tried all the different bleeding methods myself. I do think outside the box my car forces me to actually lol. And after 3 years, I'm prepared to say that there is zero reason why the car needs to be bled that way.

I have just replaced my radiator, and was there when an E34 buddy of mine changed his radiator a year back, and on both occassions we did normal bleeding and it worked fine.

Removing the radiator should not introduce air into the engine and block. When you are replacing the radiator, you have usually allowed the system to cool down in order to work on it. The thermostat would likely be closed shut, even if the gauge does not show that it is cold. Removing the hoses and the radiator cannot introduce air into the engine...there is no way that could happen. And even if air entered physically, the thermostat is located at or near the top of the engine and not the bottom so not much air would push its way in, nor coolant drain out through gravity to be replaced by air.

I acknowledge that yourself and a few others have had to perform extreme measure to successfully bleed their radiator, and that these methods worked to solve the immediate problem at hand. I still think that there was something wrong in the system, or something that the driver overlooked in the original method, that lead to this. If you had no choice but to do something that others don't, and if your situation (that of major air pockets introduced through major work such as changing the radiator) has not been alluded to separately in the Bentley manual, then it is unusual. And as I mentioned earlier, the real problem may not be serious, or may be intermittent, which is why there has been no recurrence or no other issues subsequently. Absence of evidence may not be evidence of absence.

My mechanic deals with late model bmws mainly and I've seen him flushing and bleeding radiators. I've never seen him use a tool like the one that you cited here (it looks interesting in any case). Just water from a can, then normal bleeding. The tool is clearly nice to have as a form of insurance but I do not think that it is required for the car.

I'm prepared to change my general purpose advice on bleeding as follows :

" Bleeding your radiator is supposed to be easy. If it is not, you're either not doing it right or you may have a minor or major cooling system component failure on your hands (the later perspective is strictly my view and is as yet unverified). If you have an overheating problem, do the Bentley bleeding procedure twice, the second time after leaving the engine to run at idle for 30 minutes (if it does not overheat while at idle). Finally, if it still overheats, jack up the front of your car or park it on an incline and do bleeding. If that solves the problem, great, but I suggest that you change your water pump and thermostat right away if you have not changed either recently, and check your rad hoses for suppleness. Bleeding is not supposed to work that way and if that's what you're doing you may have a major or minor situation elsewhere. "

Sir, you now have someone who has witnessed two E34 radiators being replaced, one on an M20 and the other on an M50 engine, and did not have a problem with bleeding or overheating. You did the same thing and you only evacuated all the air after using extreme measures and after repeated use of the normal method failed. This is a direct physical contradiction to your experience. You also know that very few people actually have this problem with bleeding the radiator, and almost all of the regular posters have never had to do it. Do you want to take the risk that what you've done was merely required because these radiators are hard to bleed ? Or that you had a different problem that, thus far has not been bad enough to develop further symptoms ?

I respectfully suggest that you change the water pump and thermostat, if you have not already done so recently. These are the only two things (apart from the hoses and radiator) that are in direct contact with the coolant. The clutch fan, if it was bad, would not have made a difference to your overheating situation. And especially considering that your final fix was achieved by pouring hot water into the rad hose directly, I do believe your thermostat is buggy. I highly recommend that you change it before it gets busted.

It may have been an isolated failure, or just one of those things. The car can indeed be capricious at times. I wouldn't take the chance, if this was my daily driver. And the wp and thermostat are known issues for the car's cooling system.



rgds,
Roberto

Last edited by robertobaggio20; 10-31-2012 at 09:29 PM.
Reply With Quote
  #17  
Old 10-31-2012, 09:04 PM
BMWFatherFigure's Avatar
BMWFatherFigure BMWFatherFigure is offline
Old School
Location: Perth, Western Australia
 
Join Date: Aug 2012
Posts: 2,311
Mein Auto: E23;E30;E38;E32;E34 +
Wow RB20, keep it brief!! I use a Lisle tool 24680 for my radiator jobs. That and a nose up stance works fine.
__________________
Good - Fast - Cheap: Pick any two.
Current:
E23 735i; E32 735iL (X 2 - 1 Alpine White and 1 Glacier Blue); E34 535i; E38 735iL; R50 Cooper; R55 Cooper Clubman.
Previous:
E21 318i; E30 318i; E32 735iL; E34 535i; E38 730iL; E53 4.4i
Reply With Quote
  #18  
Old 10-31-2012, 09:28 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Quote:
Originally Posted by S406 View Post
Holy mother of god what a hassle to bleed the air out! Simple hose replacement took over an hour....Thanks for the tips guys.
Thermostat and water pump changed recently ?
Reply With Quote
  #19  
Old 10-31-2012, 10:01 PM
down19992000 down19992000 is offline
Officially Welcomed to the 'Fest
Location: nc
 
Join Date: Feb 2010
Posts: 116
Mein Auto: 1995 525i
Reading your response makes it painfully obvious that you do not know how the cooling system works in a car. Think about this when you drain the coolant and take out the radiator and put a new one in its place it has no coolant in it just you guessed it air! You hook the lower hose up to the radiator and it has no coolant in it it has yeah you guessed again air! You hook the upper hose up and bang guess what there is air there too. Now you fill the radiator up with coolant and sometimes there is an air pocket in the lower radiator hose where it connects to the water pump. You do know that coolant flows DOWN through the lower radiator hose to the water pump then up through the engine until it comes to the thermostat then it comes out your upper radiator hose and back into the radiator for cooling. I guess pelican parts is pulling a fast one on people when they claim that modern vehicles get air trapped in their cooling system. Listen my car NEVER got hot until I put the new radiator in it and it got an air pocket in it which I fixed by dumping hot water down the upper hose which got water in the water pump letting it catch prime and thereby being able to circulate coolant. Simple as that I don't have a buggy thermostat. Surely you can understand a close system can get air in it causing it to not function correctly. The same thing happens when you get air in a brake line you have to bleed it out. You seem stuck on the fact that if something didn't happen to you personally it is an impossibility. Let me get this straight. If I do something that you say you don't need to I am somehow wrong. While you practice this diesel flushing while BMW tells you that it isn't needed and you somehow are correct. You can't have it both ways Roberto. When you do it its saving money and good for the vehicle. Now I do something that is unconventional and you say it is unneeded. You really should try and think outside the box on things. You will never reach nirvana without trying new things. Also go about this being at supreme peace and zen with yourself and your car. You state that removing the radiator and hoses cannot allow air into the engine. What planet are you from? You do know we breath it right?It is all around us. Think about what you write before you post. Don't just post to try and prove me wrong. Maybe you should take an auto tech class at a local community college. I am just gonna add you to my ignore list because you can be proven wrong and in your fairy tale world of your parents basement you are never wrong.

Last edited by down19992000; 10-31-2012 at 10:09 PM.
Reply With Quote
  #20  
Old 10-31-2012, 10:16 PM
down19992000 down19992000 is offline
Officially Welcomed to the 'Fest
Location: nc
 
Join Date: Feb 2010
Posts: 116
Mein Auto: 1995 525i
Roberto here is a link to how a cooling system in a car works buddy. Study it first post second
http://www.2carpros.com/articles/how...g-system-works


http://auto.howstuffworks.com/cooling-system.htm

Last edited by down19992000; 10-31-2012 at 10:21 PM.
Reply With Quote
  #21  
Old 10-31-2012, 11:06 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Quote:
Originally Posted by down19992000 View Post
Reading your response makes it painfully obvious that you do not know how the cooling system works in a car. Think about this when you drain the coolant and take out the radiator and put a new one in its place it has no coolant in it just you guessed it air! You hook the lower hose up to the radiator and it has no coolant in it it has yeah you guessed again air! You hook the upper hose up and bang guess what there is air there too. Now you fill the radiator up with coolant and sometimes there is an air pocket in the lower radiator hose where it connects to the water pump. You do know that coolant flows DOWN through the lower radiator hose to the water pump then up through the engine until it comes to the thermostat then it comes out your upper radiator hose and back into the radiator for cooling. I guess pelican parts is pulling a fast one on people when they claim that modern vehicles get air trapped in their cooling system. Listen my car NEVER got hot until I put the new radiator in it and it got an air pocket in it which I fixed by dumping hot water down the upper hose which got water in the water pump letting it catch prime and thereby being able to circulate coolant. Simple as that I don't have a buggy thermostat. Surely you can understand a close system can get air in it causing it to not function correctly. The same thing happens when you get air in a brake line you have to bleed it out. You seem stuck on the fact that if something didn't happen to you personally it is an impossibility. Let me get this straight. If I do something that you say you don't need to I am somehow wrong. While you practice this diesel flushing while BMW tells you that it isn't needed and you somehow are correct. You can't have it both ways Roberto. When you do it its saving money and good for the vehicle. Now I do something that is unconventional and you say it is unneeded. You really should try and think outside the box on things. You will never reach nirvana without trying new things. Also go about this being at supreme peace and zen with yourself and your car. You state that removing the radiator and hoses cannot allow air into the engine. What planet are you from? You do know we breath it right?It is all around us. Think about what you write before you post. Don't just post to try and prove me wrong. Maybe you should take an auto tech class at a local community college. I am just gonna add you to my ignore list because you can be proven wrong and in your fairy tale world of your parents basement you are never wrong.
No Sir you're quite mistaken. There was new reliable information thrown up during the diesel flush thread of a few days back, that did not appear last year or years before when I similarly discussed this. This new information came from very reliable sources, namely bmwff and drbert. The confluence of these two sources has caused me to modify my opinions about it. Without going into an exhaustive rerun :

1. Diesel desludges engines and cleans fuel systems.
2. Diesel flushes are safe for both the engine and fuel systems. There is no damage to engine bearings etc, and the fuel system. Teardowns have proven this. The protests in my thread of last year solely focused on diesel damaging the car. It did not touch on whether it ultimately helps enough to be worth doing. This is an important difference this year. This is something new.
3. Diesel crankcase flushes help only when there is sludge buildup in the engine.
4. If you change your oil at the oil manufacturer's recommended intervals, and if you use premium oil (Mobil1 fully synthetic extended life is under $30 at walmart, and lasts 15kmiles, so everyone can afford it), you will probably never get any sludge, and even if it does build up, it will not be enough for a diesel flush to make any difference in removing it. So you don't have to do this at every oil change. (this is a big change from my initial views).
5. Similarly, diesel fuel system flushes generally tend to have an effect on an already dirty fuel system. Changing a fuel filter is likely to be all that you need to keep it clean.
6. My new recommendations are to do a diesel crankcase flush once upon purchasing a car from someone else, and during the first oil change. You need not do it after that, no sweat. If you've just bought an E34, change the fuel filter and then do the diesel fuel system cleaning, but not before changing the filter. Do a diesel fuel system cleaning once every 3 months to keep your fuel system in tip top shape.
7. Beyond reasonable doubt, off the shelf fuel system cleaners and engine flushes are a real waste of money, if not of time as well, if you are dealing with a well maintained vehicle of any vintage.

I don't just listen to what bmw or bentley says and follow blindly if its something that can be critically thought through at my level and if there is anecdotal evidence that challenges some of their assumptions. Such critical thinking would, if the primary information and understandings are correct, lead irresistably to the same or nearly the same conclusions as the printed manuals. However, they don't always do so, and the difference may sometime prove relevant.

I will read up on the coolant workflow on the links that you've posted before I respond to that. Thank you for the links.

Last edited by robertobaggio20; 10-31-2012 at 11:12 PM.
Reply With Quote
  #22  
Old 10-31-2012, 11:14 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Quote:
Originally Posted by down19992000 View Post
Listen my car NEVER got hot until I put the new radiator in it and it got an air pocket in it which I fixed by dumping hot water down the upper hose which got water in the water pump letting it catch prime and thereby being able to circulate coolant. Simple as that I don't have a buggy thermostat.
I'm sorry I don't quite follow you here. Could you reexplain ? If you don't mind. Or anyone else, if I've been ignored.

Last edited by robertobaggio20; 10-31-2012 at 11:15 PM.
Reply With Quote
  #23  
Old 11-01-2012, 02:20 AM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Quote:
Originally Posted by down19992000 View Post
Now you fill the radiator up with coolant and sometimes there is an air pocket in the lower radiator hose where it connects to the water pump. You do know that coolant flows DOWN through the lower radiator hose to the water pump then up through the engine until it comes to the thermostat then it comes out your upper radiator hose and back into the radiator for cooling.
From the following diagrams suggest that the lower and upper radiator hoses meet in the middle at the thermostat and not the water pump as you have said. The thermostat is the junction. The water pump is located in a separate cavity in the engine block a short distance below the thermostat.

http://www.realoem.com/bmw/showparts...31&hg=11&fg=05

http://www.realoem.com/bmw/showparts...31&hg=11&fg=35

The water pump circulates water INSIDE the block, while the thermostat releases water OUTSIDE the engine. The two water circuits in the car....within the engine, and within the radiator-hoses-radiator, meet at the junction created by the thermostat. The thermostat separates both loops. This is how it seems to work for the M50 engine. The thermostat regulates the exchange of hot coolant from the engine's hot water circuit and the radiator's cold water circuit.

The attached photo is clearer (please ignore the coloured arrows).

The inference here is that in down's case the thermostat was not properly installed, perhaps it was not sitting properly in its space, perhaps it was slightly damaged or buggy and was not opening properly to allow trapped air out. When you poured hot water into the upper coolant hose, you triggered the normal function of the thermostat somehow. That seems to be the logical inference here. Someone please point out the error in this thoughtflow.

NB : lets also consider the fact that some suggest that a small hole should be drilled in the thermostat's 12 o'clock position to enhance bleeding.


rgds,
Roberto

p.s. I've mentioned this elsewhere but I'll say it again. The engine's normal functioning breaks down large air pockets into smaller ones, and channels them out to the radiator where they tend to accumulate right under the bleed screw as air bubbles float to the highest point that they can. I can say this through direct personal experience as I once many moons ago bleed my radiator twice after flushing it, 7 days apart, and found ALOT of bubbles on the second bleeding, as if the radiator had never been bled before. There had been NO HINT of overheating in the intermediate period and I drive the car daily. Anyway this also proves that air bubbles in engines are not show stoppers except in the extreme and those may well be the result of other problems with the car rather than poorly done bleeding. And even when I changed my radiator recently, I did not have any difficulty bleeding the radiator or any overheats in the engine, which suggests that very little air if at all enters the engine itself during a change of radiator and hoses.
Attached Thumbnails
Click image for larger version

Name:	M50 front.jpg
Views:	59
Size:	111.0 KB
ID:	348041  

Last edited by robertobaggio20; 11-01-2012 at 03:30 AM.
Reply With Quote
  #24  
Old 11-01-2012, 02:26 AM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Here's the next generation in cooling systems that I encountered while reaquainting myself with cooling systems. It does away with the thermostat and water pump entirely, has no moving parts so it will never break down, and lasts for the life of the engine, and does not require intermediate maintenance :

Reply With Quote
  #25  
Old 11-01-2012, 05:05 AM
snowsled7 snowsled7 is offline
The Ornery Old Man
Location: SW Mountains
 
Join Date: Mar 2012
Posts: 980
Mein Auto: GTI
Quote:
Originally Posted by robertobaggio20 View Post

And even when I changed my radiator recently, I did not have any difficulty bleeding the radiator or any overheats in the engine, which suggests that very little air if at all enters the engine itself during a change of radiator and hoses.
More fail, bobby, fail, fail, fail. Air can easily enter the cooling system during the change of components. The thermostat is a gate valve but what you FAIL to conceptualize is that there is no gate on the other end and bubbles migrate up. So when you fill an empty radiator some air passes up into the engine through the lower hose (no thermostat there).

You FAIL to understand that there are NOT two circuits but one system. The thermostat is there to regulate engine temp. Assuming no water moves around in the system when it is closed is again a failure to understand.

Time for more study before posting, as already suggested, bobby. I think you need to spend more time reading and learning that posting. Almost half the posts in the thread are yours, yet one has to wonder why? You clearly do not have the answers but want to give advice. Thats some scary stuff right there.
__________________
Current ride... '13 GTI Wolfsburg
BMW's from my past...
'92 535i/5 '89 325ix/5
'98 750iL '86 325(e)/5
'95 740iL '84 318i/5

Last edited by snowsled7; 11-01-2012 at 05:15 AM.
Reply With Quote
Reply

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E34 (1989 - 1995)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On



Forum Jump


All times are GMT -7. The time now is 01:58 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms