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
  #26  
Old 10-12-2012, 09:22 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
You mention alot about bubbles but you are unclear. Where were the bubbles coming from.

Did you continuously feed the expansion tank with a slow running hose ? Why ?

Fill up the expansion tank and remove the rad cap and bleed screw. Start the engine and let it idle. Since it does not overheat when its not being driven, you can come back 15-30 minutes later.

Bubbles coming out through the bleed screw is ok, and even then, they wouldn't come out for like 30 minutes unless you've completely drained your block and radiator and are filling everything up from scratch.

If you are getting bubbles IN THE EXPANSION TANK, then you've got a serious problem.

The auxiliary water pump only controls hot water running through the dashboard i.e. cabin heater. It plays no functional role in the cooling system. Please ignore it for now, but do ask your friend to reconnect it back on Monday, its just a 2 minute job for someone who knows his way around this car.

There's a good possibility that its your water pump or thermostat that is busted. But, if you are getting bubbles IN THE EXPANSION TANK, you've got a very serious problem.

You should go back and ask your son what he did to the car (or what others might have done to the car) in the days leading up to this situation.

Good luck.

Last edited by robertobaggio20; 10-12-2012 at 09:24 PM.
Reply With Quote
  #27  
Old 10-12-2012, 10:06 PM
My525iT My525iT is offline
Officially Welcomed to the 'Fest
Location: Florida
 
Join Date: Aug 2011
Posts: 127
Mein Auto: 92 525iT Wagon M50
M50s are not that tough to bleed. No doubt you did it properly. If the car overheats your best bet would be to replace the thermostat - even if it is not the original problem. Make sure you drill a bleed hole at 12oclock on the new one. Makes bleeding a cinch.

I believe the fluid should travel from the upper to the lower rad hose. Therefore if the tstat and water pump are working properly the rad should cool it down towards the lower hose. From everything I read not sure I could rule out water pump/fan clutch/aux. fan/rad blockage.

You can run a head gasket test pretty easy. Go to autozone or other and borrow their fluid reservoir. By a bottle of HG fluid, stick it on the rad and it will change colors if gas is in the coolant. Great for peace of mind.

Also, you can jump the aux fan with a paper clip and leave it on high when you drive to keep the engine cool. (No it is not a fix).
Reply With Quote
  #28  
Old 10-12-2012, 10:10 PM
My525iT My525iT is offline
Officially Welcomed to the 'Fest
Location: Florida
 
Join Date: Aug 2011
Posts: 127
Mein Auto: 92 525iT Wagon M50
Here is a great test procedure. I rewrote it into a flow chart which I keep in my Bentley.

http://www.bimmerboard.com/forums/posts/697674/
Reply With Quote
  #29  
Old 10-12-2012, 10:14 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Quote:
Originally Posted by My525iT View Post
M50s are not that tough to bleed. No doubt you did it properly. If the car overheats your best bet would be to replace the thermostat - even if it is not the original problem. Make sure you drill a bleed hole at 12oclock on the new one. Makes bleeding a cinch.

I believe the fluid should travel from the upper to the lower rad hose. Therefore if the tstat and water pump are working properly the rad should cool it down towards the lower hose. From everything I read not sure I could rule out water pump/fan clutch/aux. fan/rad blockage.

You can run a head gasket test pretty easy. Go to autozone or other and borrow their fluid reservoir. By a bottle of HG fluid, stick it on the rad and it will change colors if gas is in the coolant. Great for peace of mind.

Also, you can jump the aux fan with a paper clip and leave it on high when you drive to keep the engine cool. (No it is not a fix).

Well, here we are, something old that's actually new to me and no doubt many others. The HG colour change fluid test. Brilliant ! Larrick please do that right away sir.

And I'd like to say, with respect to 525it, that drilling holes in the thermostat is completely unnecessary. I've never done it and it has never made anything difficult. You don't have to be worried if you don't do it. Its another myth for the modern age, that may have had a relevance in an earlier era.

I agree that you should change your thermostat and water pump. Oreilly's sells a composite impeller thermostat for around $50, with a lifetime warranty. If the HG fluid test checks out and your HG is ok, then please change both the thermostat and the water pump. They both have approximately the same life span, if I'm not mistaken.

Just remembered. Another way to check for HG problems is via the compression test.
Reply With Quote
  #30  
Old 10-12-2012, 11:46 PM
manuelwindows manuelwindows is offline
Officially Welcomed to the 'Fest
Location: Eugene, Oregon
 
Join Date: Oct 2012
Posts: 134
Mein Auto: 1994 530i, 1977 320i
Well if you're gonna use your wife as an excuse, then you should use that "safety issue" blank check for all it's worth. If you're gonna pay that much for the diagnosis and there's a dealership around, you can get it at the dealership for that much or less and might have better diagnostic equipment, probably have better diagnostic equipment than your guy's shop and more importantly, if any of it is under factor recall, the dealership has to tell you and do the work for free.

And this is not something I would recommend and don't work for BMW and the dealership is a rip off 99% of the time but sometimes it is worth it just for the diagnosis and information on factory recall that they have in their computer database. And I'm only suggesting this cause I took my 94 530i in to the dealership for an engine diagnosis and the e-prom and thermostat are still under factory warranty in that car so all of the work was done by BMW even though it is a 94 and I am the third owner. Anyway, there's that. Get to tell them exactly what is wrong and see if you can get the parts and work done much more reasonably priced by that guy you know.

I would love to see that database, by the way.
Reply With Quote
  #31  
Old 10-13-2012, 12:00 AM
manuelwindows manuelwindows is offline
Officially Welcomed to the 'Fest
Location: Eugene, Oregon
 
Join Date: Oct 2012
Posts: 134
Mein Auto: 1994 530i, 1977 320i
oh, by the way, sorry if that post seemed like it was telling you to do anything. I really don't know what the correct thing to do is for this situation but just having been around a bunch of mechanics shops and different dealerships and observing their behavior in general with fixing my BMWs over like the past 15 years, when I used to be able to afford a mechanic, is also what my comment is based on, more than mechanical knowledge.

So sorry if I came off like I was telling you what to do as I read that post twice it may have seemed overbearing. The wife is a legitimate excuse to pay a mechanic and is my personal favorite so I also did not mean to denigrate that aspect of your dilemma.

And I wish you the best of luck with this.
Reply With Quote
  #32  
Old 10-13-2012, 07:28 AM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Quote:
Originally Posted by My525iT View Post
Here is a great test procedure. I rewrote it into a flow chart which I keep in my Bentley.

http://www.bimmerboard.com/forums/posts/697674/
Outstanding writeup mate. I've saved it to plagiarise later.
Reply With Quote
  #33  
Old 10-13-2012, 11:19 AM
Larrick Larrick is offline
Officially Welcomed to the 'Fest
Location: Berkeley California
 
Join Date: Sep 2009
Posts: 515
Mein Auto: 1994 525it
There are no bubbles in the expansion tank.
The reason that I used a slow running hose was that I was getting tired of hand feeding water every minute or less.
The bleed screw was removed and the rad cap off. Coolant flowed from the bleeder hole with massive amounts of bubbles.
This was endless and the bubble consistency never changed.
The expansion tank needed constant filling or the bleed hole became "dry" and only steam or nothing came out.
I feared that if it were not constantly toped off that air may be being sucked back into the system.
The top hose never felt "full" to me but I do not know how it is supposed to feel.
There is no apparent leak to account for lose of coolant.
Perhaps more coolant was lost in the initial overheating than I know of but that should not matter once it is refilled.
I bled the engine for over 1 1/2 hours.
The engine does not overheat at idle and the temp needle sits at 1/2 or a needle width above or below 1/2 the entire time.
The test procedure the My525it describes is for engines overheating at idle. Mine does not.
I am confused about the fan clutch. My fan comes on immediately and remains on.
The fan clutch seems fine. I did the newspaper test and it stopped and then stared again.
While cold it moves with a little resistance as described in Bentley.
I will start it again and see how long things take to heat up.
Last time the needle was just below 1/2 after 15min. and the top hose was slightly warm, bottom hose was cold.
Bottom hose warmed at about 30min.
The HG test sounds interesting.
Reply With Quote
  #34  
Old 10-13-2012, 02:12 PM
Larrick Larrick is offline
Officially Welcomed to the 'Fest
Location: Berkeley California
 
Join Date: Sep 2009
Posts: 515
Mein Auto: 1994 525it
After more reading about the newspaper test. I may have done it incorrectly.
I had a wad of rolled up paper and stopped the fan at the end of the blades.
It seems that a single rolled sheet should be used and pressure at the hub.
The fan does not stop but slows and then picks up speed after release.
That seems to indicate the clutch is ok.
According to my reading about the fan clutch:
A bad fan clutch would cause an over heat at idle.
The fan does not play a big roll in cooling the engine once the vehicle is moving and especially at higher speeds.
Since I only over heat once I am moving, I assume the fan is good.
I started the car again today;
No noise. no white vapor.
5 min. needle into blue, top hose warm
15 min. needle just below 1/2, some visible white vapor from exhaust.
20 min. needle at 1/2, some visible smoke. Bottom hose warm.
"Ticking" noise begins. I believe it is the valves. They quiet down when rpms are raised.
run for another 10 minutes and take out for a ride:
needle creeps up near 3/4 and holds for a few minutes and then creeps to near Red.
I pull over and needle comes down a bit.
I drive home and let idle, temp drops to 3/4. NO white vapor is visible.
I turn off engine and temp comes down to just above 1/2 in a few minutes.
I see no leaks.
I will allow to cool and see f I am still getting bubbles when bleeding.
I will allow the BMW mechanic to do a diagnostic on Monday.
Reply With Quote
  #35  
Old 10-13-2012, 07:03 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
You should not be doing bleeding for 1/2 an hour. The longest it has taken me is 5 minutes after the engine has warmed up. Of course, I've done this for 1/2 hour after full warmup, but I realise now that it was an overkill and unnecessary.

I should have put the time interval in my initial instructions on how to bleed the radiator. I'll ammend it now.

If you are still getting tons of bubbles like 60 or 90 minutes after you start bleeding, you've got a different problem.

I'm not exactly sure if there is a way to check if either the water pump or thermostat is working. I would suggest the following (and you should do this yourself) :

1. Try the HG solution. If it doesn't change colour (thus indicating HG failure or worse), then change both the water pump and thermostat. That should fix your problem. Either component is probably screwed or getting near screwed. And if they do need to do a head gasket job on your car, you'll need to change the wp and thermostat as well anyway.

2. Why didn't you try the HG solution already ?

When you change the water pump, change the water pump's pulley as well. They have a new pulley that is made of high temperature plastic and not the original metal. Made my engine go faster...I'm very pleased ! So this is a great way to turn a repair into an upgrade.

Of course, it might be a good idea to change the belt as well at this point.


Good luck.
Reply With Quote
  #36  
Old 10-13-2012, 08:45 PM
Larrick Larrick is offline
Officially Welcomed to the 'Fest
Location: Berkeley California
 
Join Date: Sep 2009
Posts: 515
Mein Auto: 1994 525it
I did not know about the HG test until last night. I made an appointment for Monday morning with a good BMW mechanic who once owned this model car. He will do a full diagnostic for $128. I am extremely busy right now as I have just returned from a trip and have a back log of work.
There are a lot of possible causes for the overheating. I should (as you and others suggest) do a full overhaul of the cooing system. I have read many, many threads about over heating the past few days and one theme stands out .
People change the thermostat, fan clutch, water pump and still have an overheating problem and more questions.
I am willing to spend $128 to get a professional's input. I appreciate all the help and suggestions that I have received and I know how much easier it would be for you all to help me out if you could actually stand in front of the car.
It is my son's car and he needs it back as soon as possible. If it were mine, I would do it myself. This is the first time that I have not. As I said before not only is the car overheating but I am getting a little heat from my wife.
Depending on the diagnostic and the price of repair, I will decide what to do.
Either do it myself or have them do it.
I will tell you all the out come on Monday night or Tuesday.
I have not done the HG test because I have committed to have it look at and tested in the shop.
I think there are multiple problems and I do not want to risk destroying the engine.
Thanks again for all you help and concern.
Reply With Quote
  #37  
Old 10-13-2012, 08:50 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
No problem Larrick. We hope to hear good news from you in a few days.
Reply With Quote
  #38  
Old 10-15-2012, 04:57 PM
Larrick Larrick is offline
Officially Welcomed to the 'Fest
Location: Berkeley California
 
Join Date: Sep 2009
Posts: 515
Mein Auto: 1994 525it
I dropped the 1994 525it at the shop this morning. I had my wife follow me and watch the exhaust for white vapor.
The cat started and ran fine without overheating. Only 3 miles.
My wife did say that she saw more white vapor form the BMW than from other cars.
I left the car with a written history of what happened and what I had done and experienced the past few days.
I got a call a few hours later. There was no circulation of coolant. So the water pump was not working.
I am going to change the water pump, fan clutch (it is a little weak), thermostat, hoses and belts.
My great concern is doing all this work with a bad head gasket.
The shop said that there was NO exhaust contamination in the coolant and pretty much assured me that the head gasket was fine.
They said that the M50 will show this amount of vapor.
Does any one have any comments?
Reply With Quote
  #39  
Old 10-15-2012, 05:38 PM
BMR_LVR's Avatar
BMR_LVR BMR_LVR is offline
Humble E34 lover
Location: Asheboro, NC
 
Join Date: Dec 2008
Posts: 5,264
Mein Auto: 1992 525i
Quote:
Originally Posted by Larrick View Post
I dropped the 1994 525it at the shop this morning. I had my wife follow me and watch the exhaust for white vapor.
The cat started and ran fine without overheating. Only 3 miles.
My wife did say that she saw more white vapor form the BMW than from other cars.
I left the car with a written history of what happened and what I had done and experienced the past few days.
I got a call a few hours later. There was no circulation of coolant. So the water pump was not working.
I am going to change the water pump, fan clutch (it is a little weak), thermostat, hoses and belts.
My great concern is doing all this work with a bad head gasket.
The shop said that there was NO exhaust contamination in the coolant and pretty much assured me that the head gasket was fine.
They said that the M50 will show this amount of vapor.
Does any one have any comments?
I think you can feel comfortable proceeding since the mechanic indicates that a blown HG is unlikely. A compression test should also confirm this, but he would probably charge you a lot for that. I am not one to typically recommend buying a lot of parts prior to failure, however, the cooling system is so critical to this engine's life. I do recommend a full coolant system overhaul when you are having problems like this. I did mine for ~$600 in parts via the internet. I did it in an afternoon taking my time. It's really not that hard.

I'm glad the news was good relative to the HG.

Good luck.
__________________
Most problems are usually something simple !

Quote:
Originally Posted by noego View Post
It's Deja Poo - as in, I've heard this **** before.
Steve

Calypso Red 1992 525i with 200K miles

1991 735i - Sold
1992 525i - Sold
1995 325is - Sold
2000 528i - Sold

Reply With Quote
  #40  
Old 10-15-2012, 07:57 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Quote:
Originally Posted by BMR_LVR View Post
I think you can feel comfortable proceeding since the mechanic indicates that a blown HG is unlikely. A compression test should also confirm this, but he would probably charge you a lot for that. I am not one to typically recommend buying a lot of parts prior to failure, however, the cooling system is so critical to this engine's life. I do recommend a full coolant system overhaul when you are having problems like this. I did mine for ~$600 in parts via the internet. I did it in an afternoon taking my time. It's really not that hard.

I'm glad the news was good relative to the HG.

Good luck.
Did you read the bimmerboard thread posted by my525iT ? It guided you on deliberate methods to check on your water pump and thermostat.

As I expected, this was a thermostat or water pump issue. I was quite sure that you were wrong when you said that most of the online posts that you've read suggest that these problems are more serious.

However, if there is no coolant circulation, your engine should be overheating even at idle. Perhaps there is coolant circulation, but it is very poor.

However, I do not like the extra vapour in your tailpipe. This is not normal for an E34, expecially if another vehicle does not exhibit the same amount of vapour (which eliminates environmental issues). If i were you, I would purchase a compression tester for $30 on ebay and do the compression test myself (its easy, check youtube) to be absolutely sure that nothing is up. Also, ask the mechanic to explain the extra vapour, see what he says.

Finally, my suggestion is that you get a composite impeller water pump, instead of a cast iron or stainless steel one. Composite pumps do not corrode, are tougher than plastic, as strong as steel, and almost as light as plastic. Thus, the load on your wp's bearings is reduced, greatly extending its service life and reducing its likelihood for sudden failure. O reilly sells one for $50 before shipping, with a lifetime warranty. Turner sells a BMW pump for around twice that price, but with no lifetime warranty.

Furthermore, I suggest that you pick up a new water pump pulley that's made of thermoplastic these days. It is much lighter than the existing metal wp pulley and your car will be faster. I just did this and am very pleased with the results. Since the pulley needs to be removed to access the fan clutch, you're not going to pay extra for labour. The pulley should cost under $50 and is worth paying for. Please confirm the material of the pulley with customer service if you're buying it online.

I would not bother to replace the fan clutch. If your car did not overheat with a busted water pump and a possibly busted fan clutch, then I think your system would be flawless with a good pump and existing clutch. In fact, I would recommend that you remove the fan clutch, fan and fan shroud entirely. I've been doing that for 2 weeks with no problems. Confirm using Bentley's test procedures first that your auxiliary cooling fan is working well at both low and high speeds, before you delete the fan clutch.

Unless you have already done so, I would suggest that you change the bleed screw and rad cap to new ones. They should only run you $15 in total.

Please purchase the compression test kit and conduct that test on your car.
Reply With Quote
  #41  
Old 10-15-2012, 07:59 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Perhaps you should do the compression test first. You can even do this yourself while at their workshop, so there will be no extra charges. The extra water vapour in your tailpipe is not right. Your mechanic may have misdiagnosed the issue. Please ask him to describe the exact steps he took to arrive at the conclusion that the wp is busted.

Last edited by robertobaggio20; 10-15-2012 at 08:01 PM.
Reply With Quote
  #42  
Old 10-15-2012, 09:32 PM
Larrick Larrick is offline
Officially Welcomed to the 'Fest
Location: Berkeley California
 
Join Date: Sep 2009
Posts: 515
Mein Auto: 1994 525it
I will. I am a bit skeptical myself.
Reply With Quote
  #43  
Old 10-15-2012, 09:54 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
It is possible that your HG leak is minor, which is why they couldn't really identify it. In which case, this might be all that you need to get rolling :





This might be the best first option for you.

If it fixes the problem, it will mean that there's no need for you to change the WP and thermostat and all the expense of that, although it is the intelligent thing to do. Perhaps you could postpone that till later when you feel like doing a full head job.

If this is the problem, you are fully justified in demanding a refund from the dealership, even if you fix it some time later. They should bloody well do a compression test on your car for that amount of water vapour shown, and for such a high price for a mere diagnostic.

And while you're there to collect the car, please double check to see if you can get them to show you how the stomp test works. And if it doesn't, they should fix it under warranty or recall or whatever.

Last edited by robertobaggio20; 10-15-2012 at 10:05 PM.
Reply With Quote
  #44  
Old 10-15-2012, 10:25 PM
robertobaggio20 robertobaggio20 is offline
Banned
Location: earth
 
Join Date: Oct 2009
Posts: 3,403
Mein Auto: car
Quote:
Originally Posted by Larrick View Post
I dropped the 1994 525it at the shop this morning. I had my wife follow me and watch the exhaust for white vapor.
The cat started and ran fine without overheating. Only 3 miles.
My wife did say that she saw more white vapor form the BMW than from other cars.
I left the car with a written history of what happened and what I had done and experienced the past few days.
I got a call a few hours later. There was no circulation of coolant. So the water pump was not working.
I am going to change the water pump, fan clutch (it is a little weak), thermostat, hoses and belts.
My great concern is doing all this work with a bad head gasket.
The shop said that there was NO exhaust contamination in the coolant and pretty much assured me that the head gasket was fine.
They said that the M50 will show this amount of vapor.
Does any one have any comments?
The M50 is not supposed to show ANY vapour at all except on a wet wet day, and even then, would show about the same amount of vapour as ANY OTHER CAR. They are full of ****. Throw that question back to them. They are such idiots. Lazy buggers do not wish to do a compression test. Insist on them doing a compression test at their expense. Ask them what are they charging you for ? Be firm.
Reply With Quote
  #45  
Old 10-16-2012, 10:50 PM
BMWFatherFigure's Avatar
BMWFatherFigure BMWFatherFigure is offline
Old School
Location: Perth, Western Australia
 
Join Date: Aug 2012
Posts: 2,144
Mein Auto: E23;E30;E38;E32;E34 +
The more I read this - particularly the original: car boiled and continuous bubbles from the bleed - the more I've got to go with HG or worse. Nothing else makes sense. I presume the radiator, water pump and thermostat all tested good?
__________________
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
  #46  
Old 10-17-2012, 06:12 PM
Larrick Larrick is offline
Officially Welcomed to the 'Fest
Location: Berkeley California
 
Join Date: Sep 2009
Posts: 515
Mein Auto: 1994 525it
The 1994 525it is back on the road and seemingly fine.
The water pump's plastic impeller was completely missing. There was NO coolant circulating except for what may have moved due to heat convection.
That is why it took so long for any heat to reach the valves for the heater core
That is why it could not be bled.
Roberto, I did read My525it's thread but did not see a test for the water pump.
You had written me that if the water pump failed, the engine should overheat at idle.
That makes sense to me too, so what is a definitive test for a water pump short of examining it out of the engine?
There must have ben a blade left on the pump while I was trying to bleed it because I removed the upper hose at the radiator and di see some movement.
But the lack of volume in the hose made me suspect the water pump.
THe thermostat seemed to operate properly.
The water vapor was the scary part but there had always been more vapor than I liked to see.
SO...This is what happened
NEW water pump, thermostat and housing, upper and lower radiator hoses, fan clutch and both serpentine belts.
The cooling system was flushed and filled.
I , on recommendation form the mechanic, changed from Mobil 1 synthetic to Castrol GTX 20W50.
This oil is good for short distance urban driving.
It seems to have quieted the valves, which had always been making a little noise.
This morning the car was showing water vapor but so where most other cars.
7:30 am and 52 degrees with dew.
I will closely monitor the coolant level and exhaust.
The mechanic assured me that the head gasket was fine.
There were zero hydrocarbons in the coolant and he can detect 1 part per million.
The oil was pure and clean.
I quizzed him on the possibility of water only entering a cylinder and not contaminating the oil or the coolant.
His contention is that would be impossible because on the compression stroke of the engine, gasses would pass into the coolant due to high pressure
if coolant were able to enter the cylinder.
He is saying that the "Hydrocarbon" test is the definitive test for a blown head gasket.
He also stated that this model car will show a bit more vapor than most cars.
It runs very smooth and very strong.
I put blue tape at the current cooling level and will watch it closely.
I would say that if there is no coolant lose after a few weeks then all is well.
The most striking thing was the condition of the water pump, absolutely tripped clean.
The heater now blows very warm air out of both passenger and driver side.
This is without benefit of a missing auxiliary pump.
THe needle now sits a needle width below 1/2.
Reply With Quote
  #47  
Old 10-17-2012, 06:28 PM
BMWFatherFigure's Avatar
BMWFatherFigure BMWFatherFigure is offline
Old School
Location: Perth, Western Australia
 
Join Date: Aug 2012
Posts: 2,144
Mein Auto: E23;E30;E38;E32;E34 +
Love a story with a happy ending! Glad it was not the HG or worse.
__________________
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
  #48  
Old 10-17-2012, 07:29 PM
Larrick Larrick is offline
Officially Welcomed to the 'Fest
Location: Berkeley California
 
Join Date: Sep 2009
Posts: 515
Mein Auto: 1994 525it
In rereading my last entry,I realized that a statement is unclear.
If the water pump had indeed failed,why did the engine not overheat at idle.
It could run for hours with the needle at the 1/2 mark.
So...what is a definitive test for a bad water pump?
Reply With Quote
  #49  
Old 10-17-2012, 09:25 PM
BMWFatherFigure's Avatar
BMWFatherFigure BMWFatherFigure is offline
Old School
Location: Perth, Western Australia
 
Join Date: Aug 2012
Posts: 2,144
Mein Auto: E23;E30;E38;E32;E34 +
How about (for a good pump) - 'One that circulates sufficient coolant for the engine under all conditions'? BTW did you find bits of the old impeller? Where did they go? When the air is cool and the thermostat fully open your water pump was able to keep up. Had the air been hotter and running the air con I guess it would boil, given time.
__________________
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

Last edited by BMWFatherFigure; 10-17-2012 at 09:28 PM.
Reply With Quote
  #50  
Old 10-18-2012, 07:14 AM
Larrick Larrick is offline
Officially Welcomed to the 'Fest
Location: Berkeley California
 
Join Date: Sep 2009
Posts: 515
Mein Auto: 1994 525it
Yes there were bits of the old impeller in the box of parts which the shop gave me. I did not do the job.
I did not have the time and my son needed his car back immediately for work.
The system has been flushed so I assume the rest if the bits are out.
In diagnosing an overheating problem, could you assume:
If the upper hose gets hot when the engine is at operating temperature then the thermostat is working.
If the engine overheats with a good thermostat, that means a bad water pump.
But mine did not over heat at idle and the outside temperature was not cool and it could idle for hours.
It only overheated under load and when moving.
Since it did not overheat at idle, the fan was doing a good cooling job.
The fan is not needed at speed.
The question is, does an engine operate at higher temperature when at idle or at speed.
I would have thought that a bad water pump would have made it overheat at idle faster that at speed.
But it was the opposite.
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 07:46 PM.


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