Cooling System

Originally Posted by 745iguy

What is this an indicator of?air? Ive been taking notes on all if this cooling system's mess. For the longest time i thought coolant pipe was the cooling systems flaw. Low and behold it is really the temperature and pressure it operates at all along that is the basis of the leakiest car i have ever owned.

Really it's not even the coolant pipe but a little black O-ring at the front and the back of the tube that fails.

And this has always been in relation to a hot block and heat over time.

Wow Great read everyone who added Info to this thread. Possible new Member here. Might be pulling the Trigger on a 03 745LI with 41,000 miles....
I live in modesto so i will be Definately doing your MOD with you SFbay Just give me the $$$

Originally Posted by sirstopher

Really it's not even the coolant pipe but a little black O-ring at the front and the back of the tube that fails.

And this has always been in relation to a hot block and heat over time.

The overall design of this engine is flawed. On an expensive german vehicle who decided:
hey! I know what we can do! Lets stick a pipe through the valley that is held on by a rubber o-ring gasket that cannot withstand the cars normal operating temperature!
Must of been to get more maintenance and warranty work
That same guy must have said hey lets have a bracket for the alternator over a passage that is only used for vehicles with the specific oil cooled version and the ones that are not lets take that same rubber and seal it up with that!
Ive said it a lot i love the car, my car isnt even causing me any trouble at the moment (yet) when i am done with this one though, i will probably stick with MB. If i do ever decide to buy a bmw again, will probably not be a v8. If you look through the f01/2 forum some people are having these same types of issues. Even reading a few reviews of the newer bodies people were complaining about jerky transmissions. Time will tell if they suffer the same fate as the e65/6 Bmw clearly dont care and openly dismisses these issues as normal.
What happened to cars that can stand the test of time?

Well the car sat overnight and I opened the cap and got air pressure, so I know it's bleeding, perhaps I just need to be patient and wait a few days for it to get the air out.. I think opening it when it's hot and squeezing on the upper hose is just adding more air.. I drained the expansion tank again, this time I was in my garage so I caught it in a bucket.. after all the draining and filling with water yesterday, it still looked dark blue, like it was all coolant.. this stuff is really concentrated evidently.. I will start it soon and let it mix again, and I wouldn't be surprised if it will be dark blue again.. I don't know about this coolant, I think your right SF, it's either junk, or the best, because it's really thick and goopey.. I don't know if that's good or bad, but I can tell you just pumping it out of the expansion tank it was bubbling up everywhere, so I really think it is either the cause or a big help with all these bubbles.

my 99 c230 benz (4cyl 2.3 DOHC supercharged) stays at 90C :P damn BMW! these little devils having a motor running at 105 :O SFBay is right they designed it this way to create problems , or it seems that way!!!!

Hey cmpcpro Ive noticed a couple of behaviors that may be same symptoms youve already encountered.When I pull up at home (now winter)car is idling 500 rpm no matter the climate setting.30 sec of idling temp goes to 107c ,fan comes on and temps stay the same.If i do the same thing and give it the gas at idle(stopped)to 750 rpm the temps set at 105c rock solid.Does this mean not enough flow at 500 rpm?I used 750 rpm because Ive noticed it idles at this speed in the summer.Oh and I always have the A/C on.

Hey SFbay I put my key to 2cd position after reaching 107c engine off.Listening to aux pump for the first min.it ran smooth but after that not much noise but would jump a little every 10 sec or so.

Originally Posted by dolfan13

Hey SFbay I put my key to 2cd position after reaching 107c engine off.Listening to aux pump for the first min.it ran smooth but after that not much noise but would jump a little every 10 sec or so.

That means you too have air or "bubbles" in your system.. same issue.. I shut the car off today at 107 and popped the hood and losened the sensor on the top of the water pump and got air/water coming out.. it may have just been presurized air and if I keep doing that it will escape, but to me it may be boiling.. problem is, even with 50/50 coolant mix (BMW) it's actualy either the same or even worse.. I am at a loss as to where to go next.. I don't understand why I am getting this horrible groaning noise again even with a brand new water pump.. I bought a new tensioner today which I will install tonight, but I don't believe it's the issue.. The bearing on the old pump seemed fine.. I don't believe they should require water to run correctly, although I may be wrong.. but something is making noise when cold, and it's loud enough that I am afraid to look under the hood when it's happening in fear it will let loose and kill me.

Originally Posted by cmpcpro

That means you too have air or "bubbles" in your system.. same issue.. I shut the car off today at 107 and popped the hood and losened the sensor on the top of the water pump and got air/water coming out.. it may have just been presurized air and if I keep doing that it will escape, but to me it may be boiling.. problem is, even with 50/50 coolant mix (BMW) it's actualy either the same or even worse.. I am at a loss as to where to go next.. I don't understand why I am getting this horrible groaning noise again even with a brand new water pump.. I bought a new tensioner today which I will install tonight, but I don't believe it's the issue.. The bearing on the old pump seemed fine.. I don't believe they should require water to run correctly, although I may be wrong.. but something is making noise when cold, and it's loud enough that I am afraid to look under the hood when it's happening in fear it will let loose and kill me.

Well don't give up, you're very close.
Valley pan will fix it!! Hope you're not mad at me valley pan is very important thing, it creates pressure in your system.
I had my first e65: had the same issue with 107-110C!!!! Then I decided my wheep hole was bad, though it wasn't leaking: I replaced everything and temp came back to 103-105, the problem is after 4 months I got that problem again;(
Valley pan had visible leak from rear bolts.
Could be steering pump as well
Or just tensioner- simply spray some wd40 and start it.

Ps. Happy new year to everyone!!

Originally Posted by SFbay

Well don't give up, you're very close.
Valley pan will fix it!! Hope you're not mad at me
Could be steering pump as well
Or just tensioner- simply spray some wd40 and start it

I'm not mad at you SF, I am very appreciative that your here.. I think I did take out too much coolant, as it is def. boiling when I crack the sensor on the water pump.. I will put back the coolant, but it seemed to run better with more water.. so I am lost.. I am going to replace the one line I forgot, which goes from water pump to trans tstat, and then I am going to replace the hose from the aux water pump to the heater block.. that's it.. I would love to get the info on your tstat, as I believe my issue is a breech when I hit such a high pressure, I believe seeing as I am losing no coolant that dropping the temp would infact solve my issue, while I know it isn't a correct "fix".. I have to think that BMW installing a fail safe for just 3deg higher than normal temp means they expected this issue to arise, so I would love to be able to get a 95c tstat in there.. otherwise my next move I think should be checking out that Evans NPG+.. thinking that will atleast drop pressure to near 0, and will solve the boiling issue.

Nope, it's incorrect:
First you need to fix the system, then improve it.
I'll be replacing the valley pan next week so I'm suggesting you the same, there is no workaround when it's bad already, the leak is very small but it does exist when heated up.
It's like that British joke:
Two hunters:
-Do you see a rabbit???
- nope, sir!!
-neither do I, but it's somewhere here for sure

Originally Posted by SFbay

Nope, it's incorrect:
First you need to fix the system, then improve it.
I'll be replacing the valley pan next week so I'm suggesting you the same, there is no workaround when it's bad already, the leak is very small but it does exist when heated up.
It's like that British joke:
Two hunters:
-Do you see a rabbit???
- nope, sir!!
-neither do I, but it's somewhere here for sure

By the way, How many miles does everyone 7 have with these leak problems? specifically SFBay, What is your Mileage???

I tried going more water then coolant and it was def. boiling.. so now I am going to add more coolant than water.. I know you keep saying leak, but can there really be a leak with absolutely no coolant loss? Also, I talked to a guy who builds BMW race engines, not sure how new of the cars he works on but when I told him that it runs wonderful when moving and goes up only at idle the first thing he said was, it sounds like your fan isn't coming on correctly.. When my fan does come on, it's not very hard and it seems to go back off very quickly.. can these fans be rebuilt? What do you think about that SF?

Yep cmpcpro I don't like the fan operation either.Im still stuck on 250 more rpm at idle and temps are 105c solid.Even drop back down to 500 rpm and temp never goes back up.105c solid from then on??WTF?

Originally Posted by Ghettobird209

By the way, How many miles does everyone 7 have with these leak problems? specifically SFBay, What is your Mileage???

SFBay has 160k or more and I have 131k.

Hey SF: I hate to keep asking, but I would love to get my hands on the specs or what you used for the 95c stat.. willing to do whatever you think is fair, but I am not losing any coolant, so I wouldn't mind trying that, even if I still have an issue, I would like to atleast start on the stat, as I will probably solve problem by then. Thanks.

Originally Posted by dolfan13

Yep cmpcpro I don't like the fan operation either.Im still stuck on 250 more rpm at idle and temps are 105c solid.Even drop back down to 500 rpm and temp never goes back up.105c solid from then on??WTF?

The fan could certainly be the key.. car runs right, tstat opens great, car will actually run great down to 102 or so and stay there.. then when coming to a stop you can tell it's like slowly loosing the battle.. slowly it goes up, up, and bam boiling and up in temp.. if you drive around again for a while starts opening again and gets cooler, meaning no longer boiling... Either have a leak somewhere that is so minute it's just sucking air in and no water out, or radiator issue or fan issue.. I wonder if the alt. could be going out and cooking the coolant? Going to start adding more coolant.. it seemed like less was better, but the last time when I filled the brand new cooling system I got close to 50/50 but still more water, and it seemed worse, sometimes tstat wouldn't even open moving, but it could have just been air in the new system... I didn't give it time.. I will buy one more bottle (my third one at $20 each) and start adding more to see if it gets better or worse.. On Wed I am picking up the last hose for cooling system and the heater hose.. besides radiator that is entire cooling system short motor/heater.

The leak thing kind confuses me because this system is under so much pressure.It would have to suck the air while cooling off after shutting down.If this was the case it wouldnt it self bleed once driving and heating up and high pressure again?,Just seems hard to believe a leak that small would raise temps that much.

Sent from my M975 using Bimmer App

Originally Posted by dolfan13

The leak thing kind confuses me because this system is under so much pressure.It would have to suck the air while cooling off after shutting down.If this was the case it wouldnt it self bleed once driving and heating up and high pressure again?

Sent from my M975 using Bimmer App

I am not sure either.. I think I am introducing air into mine while opening it warm.. The reason I say is, if I open it warm and I hear the pressure go, I think it is sucking in air while equalizing. If I put the cap back and open it in morning when completely cool I will get air noise too, which tells me it's actually releasing air.. so I believe this system bleeds when it's cold. I would guess opening the cap is when it lets the air out.. I too am lost on the theory of this, as I am not losing coolant and the system is at 200PSI.. so at that pressure I would think it would be shooting coolant out anywhere it could.. but it only seems to suck in air.. Also, I notice that if I fill it at a level, and open it warm it will be higher, so either water is still hot and expanded or I have or it has sucked in air.. I have been cracking sensor on water pump trying to release air.. not sure if it is high enough though, doesn't seem to be as the vent pipes are higher, but who knows.

i guess im in between 146k
no leaks atm but i want to do this asa i can. i think i will have this for much longer if i do this tstat w/ npg w/ no leaks currently

Ok, guys calm down:
I had 3 e65s already within 5 yrs.
All of them had similar cooling issues:
- fan is totally functional and has nothing to do with it
- fan won't kick in just bc lower hose is not that hot enough less than 65C.

Btw The racing guy knows nothing about engines
The lowest miles e65 had 87k miles
And same fking problem, so I fixed tranny and sold it.
Only 160k miles was doing okay, but not for long;(
Leak can be very small and will take time to notice but enough to not bleed the system.
Or only bmw coolant can sustain that crazy heat? Idk I'll try for some fun bmw coolant and oem tstat, but I definitely have a leak.
Did anyone try any other coolant than bmw one??

Originally Posted by SFbay

Ok, guys calm down:
I had 3 e65s already within 5 yrs.
All of them had similar cooling issues:
- fan is totally functional and has nothing to do with it
- fan won't kick in just bc lower hose is not that hot enough less than 65C.

Btw The racing guy knows nothing about engines
The lowest miles e65 had 87k miles
And same fking problem, so I fixed tranny and sold it.
Only 160k miles was doing okay, but not for long;(
Leak can be very small and will take time to notice but enough to not bleed the system.
Or only bmw coolant can sustain that crazy heat? Idk I'll try for some fun bmw coolant and oem tstat, but I definitely have a leak.
Did anyone try any other coolant than bmw one??

Thats what I would like to know, because I am thinking either BMW coolant is great, or absolute junk.. Too little and water boils... too much and it foams/bubbles with any movement/jolt.. I don't believe coolant should do that.. I would still love to start working on 95c tstat if possible, ofcourse I'm willing to pay for your time/money spent, IF you want to give it out. I don't totally know if I have a leak yet, I mean, I understand what your saying, and I see how that could be, but I don't have any coolant loss.. I think it's a combination of either boiling or this BMW coolant bubbling.. one plus side of new cooling system: When moving the car runs alot cooler, it used to cycle from 105/103, but now it will run down to 101 or so, until coming to a stop, also AUX water pump runs solid all the time now until it starts to run above 106. Which coolant did you try SF? Prestone? Which coolant is the best? There are a few Evans waterless coolant guys around here, I called one, who was out will order more on Wed. and the other guy was closed, I'll call him on Wed, and didn't bother calling the farther places yet until checked the two soonest..

Also update on groaning noise: I replaced the top tensioner next to water pump.. when it was warm it sounded fine, now that it's cooled off and I spin it I have a vibration and it makes a slight noise, so hoping that was it.. which means my water pump with 50k on it was fine.. lol

Originally Posted by cmpcpro

Thats what I would like to know, because I am thinking either BMW coolant is great, or absolute junk.. Too little and water boils... too much and it foams/bubbles with any movement/jolt.. I don't believe coolant should do that.. I would still love to start working on 95c tstat if possible, ofcourse I'm willing to pay for your time/money spent, IF you want to give it out. I don't totally know if I have a leak yet, I mean, I understand what your saying, and I see how that could be, but I don't have any coolant loss.. I think it's a combination of either boiling or this BMW coolant bubbling.. one plus side of new cooling system: When moving the car runs alot cooler, it used to cycle from 105/103, but now it will run down to 101 or so, until coming to a stop, also AUX water pump runs solid all the time now until it starts to run above 106. Which coolant did you try SF? Prestone? Which coolant is the best? There are a few Evans waterless coolant guys around here, I called one, who was out will order more on Wed. and the other guy was closed, I'll call him on Wed, and didn't bother calling the farther places yet until checked the two soonest..

Also update on groaning noise: I replaced the top tensioner next to water pump.. when it was warm it sounded fine, now that it's cooled off and I spin it I have a vibration and it makes a slight noise, so hoping that was it.. which means my water pump with 50k on it was fine.. lol

And I told you not to replace anything, right?) we could have spent 800$ on something else (nice hookers and drinks)))))

Anyhow don't worry even with pure water it should not boil, so the answer is damn leak with air fking pockets!!!!

The pressure cap on a cooling system is the key to raising the boiling point of the 50/50 mix of antifreeze and distilled water. For every pound of pressure cap rating the boiling of point of the above mixture raises 3 degrees. If you had plain water in your cooling system with a 15 pound pressure cap the water would boil @ 257 degrees. If you had a 50/50 mix of antifreeze and water the coolant would boil @ 265 degrees with a 15 pound cap. The boiling point would raise to 270 degrees if you had a 60% antifreeze mixture with a 15 pound cap. If you had a 70% mixture the boiling point would raise to 276 drgrees.
So..... Fix the leak

Originally Posted by SFbay

And I told you not to replace anything, right?) we could have spent 800$ on something else (nice hookers and drinks)))))

Anyhow don't worry even with pure water it should not boil, so the answer is damn leak with air fking pockets!!!!

The pressure cap on a cooling system is the key to raising the boiling point of the 50/50 mix of antifreeze and distilled water. For every pound of pressure cap rating the boiling of point of the above mixture raises 3 degrees. If you had plain water in your cooling system with a 15 pound pressure cap the water would boil @ 257 degrees. If you had a 50/50 mix of antifreeze and water the coolant would boil @ 265 degrees with a 15 pound cap. The boiling point would raise to 270 degrees if you had a 60% antifreeze mixture with a 15 pound cap. If you had a 70% mixture the boiling point would raise to 276 drgrees.
So..... Fix the leak

Ah I see, so playing with the coolant mixture isn't important really.. so what still throws me off is why I have never lost any coolant.. And how it seems like everytime I drain it works from perfect to horrible.. Could there be anything else that could cause this system not to bleed but without a leak? Wondering if the heater valves the aux water pump goes into could be sucking air somehow.. Also, when I start my car after it's been off for a while even after not using the heater I will get hot air from the vents for a couple minutes.. I was told that could happen when having a low batt. and I did at the time, but new batt. and programmed, and still happens.. doubt it's related but at this point who knows.

Well took off the cap tonight after car cooled off completely.. Coolant went from a little above max to below min.. so seems like it may have got some serious air out.. Will drive it tomorrow.

Originally Posted by cmpcpro

Well took off the cap tonight after car cooled off completely.. Coolant went from a little above max to below min.. so seems like it may have got some serious air out.. Will drive it tomorrow.

So seems like you're wasting your time)) You're just repeating my mistakes over and over....
It's 2013 and your car is 10yrs old already
I'm not getting why don't you try what I told you from very brginning??? Valves are good if it blows hot air.
-bypass heater core
-replace valley pan