OMG! It's STILL overheating! - BMW Forum

reepicheep_85 · 07-14-2007, 02:45 AM

So I was having trouble with my 92' 325is overheating a few weeks back and it has been giving me trouble ever since. I started with the cheapest and easiest things first: Thermostat, new gaskets, new aluminum t-stat housing) It was still overheating, so I went ahead and changed the water pump as well. That seemed to work fine for about two days of hot, heavy traffic driving and then I started losing coolant. I spent the better part of a week trying to figure out where it was leaking from and finally figured out it was the heater core, so I replaced that as well. Now, there are no more leaks and I am not losing coolant at all. I have tried flushing the system several times, I always use distilled water and burb the system correctly and i have tried various ratios of anti-freeze to water. I have used redline water wetter in all and also tried Royal Purple's Purple Ice and straight water. I know that at this point I should be thinkg head gasket, but it doesn't exhibit any signs of being bad. There is no oil in the water nor water in the oil. I haven't lost any power, water level is staying full and there is no water coming from the tailpipe. ( except for minor condensation). The only things I haven't replaced are the radiator (was replace a little over a year ago) and the fan clutch. The fan seems to spins at the same speed as the motor and increases with the RPMs but I don't know what else it is supposed to do. Does it have another stage that it goes through? I have gotten the car to stay cool enough that I can drive it for about 6-8 miles at a time before it starts to over-heat. Anyone have any ideas? I am trying to get this thing fixed so that I can get it sold and I don't want to deal with it any more. Thanks is advance for any help I get!

reepicheep_85 · 07-14-2007, 02:46 AM

P.S. Holy crap. Sorry that was so long winded.

Criminal · 07-14-2007, 11:57 AM

Does the small electric fan work? (the one in front of the radiator)

Try to swich on the AC, It should work right away.

Also Check the Pipes coming from the radiator, May be clogged or something.

reepicheep_85 · 07-14-2007, 12:44 PM

yeah, the aux. fan works fine and all of the hoses are clear. I've run a few flushes through the whole system too.

Starmavin · 07-15-2007, 01:34 AM

A thermostat installed backwards would cause all of these problems. Or the plastic impeller fell off the water pump, very common.

reepicheep_85 · 07-15-2007, 11:06 AM

Well I thought that it may be the t-stat not opening, so I tried running without it completely and it still overheats. I also bought a new waterpump because I thought maybe it got too hot and damaged the impeller, but when I took the old one out it was fine. After all of that it still overheats. I can drive the car for about 15 min. after it has reached operating temp before it starts to overheat. Is there a chance it could be my fan clutch? I'm not sure how it should behave.

mmendell · 07-15-2007, 03:38 PM

I just changed everything in the cooling system EXCEPT the clutch fan. Considering all that you've replaced in the system so far, it makes sense to do that one next. It's certainly an easy and relatively inexpensive job.

walke40 · 07-15-2007, 06:35 PM

If you are not loosing water, maybe it's the temprature sender in the block or the gauge it's self. If an engine boils you get steam and lots of water on the floor. One other thing - Have you changed the rad cap?

Starmavin · 07-15-2007, 10:27 PM

Are you getting heat from the vents with it in the hot position?

reepicheep_85 · 07-16-2007, 12:00 AM

Quote:

Originally Posted by Starmavin

Are you getting heat from the vents with it in the hot position?

No, I'm not. That's why I took the water pump out the other day to make sure it was good.

Quote:

Originally Posted by walke40

If you are not loosing water, maybe it's the temprature sender in the block or the gauge it's self. If an engine boils you get steam and lots of water on the floor. One other thing - Have you changed the rad cap?

I actually haven't changed the cap, would it really make that big of a difference? I know it made a little difference in an old pontiac that I had, but it wasn't enough to make the whole thing overheat like it does.

WarNox · 07-19-2007, 08:16 AM

i doubt that it will be the cap, nah it won't be the cap :d

the main fan at the front. leave your car running for say 8min, when it starts to get hot that fan should start spinning faster then it will for the first few min. Try stopping that fan when you first start the car, you should be able to stop it no problem (use a screwdriver, not your finger

), but later on when it actually clicks on it shouldn't be stopped as easily. if that fan doesn't start spinning any faster when the car gets hotter there is your problem.

it isn't electrically controlled btw.

let me know.

reepicheep_85 · 07-19-2007, 06:47 PM

are you talking about the fan that is driven my the engine? It only comes on at one speed. That doesn't really explain why I'm not getting any heat from the heater though.

hunter325i · 07-19-2007, 10:24 PM

i had a problem with my 325i as well conserning my radiator. i too did the same things that you did, but it turned out that the problem was a small crack in the radiator which was not letting it have the pressure that it needed. i never lost water but because it was just enough of a crack to let air release droping the pressure

reepicheep_85 · 07-20-2007, 09:19 PM

Well I just replaced the radiator, so I'm guessing that's not the case.

hunter325i · 07-21-2007, 03:15 AM

well my friend, not sure what to tell you, seems like you have exhausted all of your options concerning your radiator....not sure if i can be of any help. i hope you get that worked out iknow how car problems can be a B!tch