:( hi i own a bmw 528i 1997 im bloody sick off it .the things is overheatig its just had a new thermostat put in its been bled the oil is topped up :( when im driving and the temp starts to go into the red i turn the heating to full and the temp level starts to drop whats going on can anyone plz help ive been looking for answers all day 8O
You bled system at 2000 RPM with heat full on? Hose clamps tight?Pin hole in radiator?Use a vacumm gauge and see if head gasket is blown!What is the ratio of water to antifreeze?
The fan clutch is a common culprit.
Why did you believe that the thermostat needed to be changed? Please don't say "because it was overheating" because many many other things cause overheating. Did you check the thermostat for proper operation? Jim
Sounds like your radiator is plugged. Pull the pump and look at the impeller as well.
Blake
Why do you think its overheating ? Just because the temp gauge says so ? Check the temp gauge....
IF it is actually overheating.....
It could be that the new thermostat is faulty - what happens with NO thermostat ? It could be because e.g. the radiator matrix is full of crap restricting the air flow through it... It could be that the water is not being circulated properly, loose fan belt, partially blocked waterways (unlikely) Is the ignition timing correct ? I think too retarded ignition causes a tendency to overheat..
I know my engine is a real sod to bleed properly/fully, so I have avoided work that does this - is yours easy to get ALL the air out / are you sure it is bled fully ?
Hope that helps......
Nick
You should also check the cat. How is your performance?
Blake
Is this with the AC in operation? If so, the electric aux fan should be running all the time.
Also, the main engine driven fan has a temperature controlled viscous coupling which should allow the fan to run at low speed with the engine at the normal temperature to save power and noise, but lock up so it runs at full speed when needed. And you should be able to hear this happening - the fan makes more noise.
On my former car, an 318i 1989 I had problems with overheating. Before I had time to check this (actually thought of replacing, or at least check the thermostat) one of the hose in/out-lets (do not remember which is which, the upper one it was) broke of in the plane of the radiator, i.e. it was too hard to fix, so I bought a new radiator. After this I had no overheating at all. So it could be that the radiator is acting up.
Lars
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