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View Full Version : Overheating problem on e34


fob
03-26-2006, 07:18 PM
Hello everybody

This morining I took my car (e34 M50 525i) to go at work and 5km's later on the highway I noticed that the temp gauge was near the red spot and it hit the spot 30secs after. The display marked : COOLANT TEMP. I stopped at the next exit. Later in the day I checked the coolant level and it was ok. BTW I was not driving hard so there must be something defective somewhere. What could it be guys?

bmwm5lover
03-26-2006, 07:51 PM
Possibly t-stat.

BigD
03-26-2006, 08:16 PM
I hope Terry is right. If it's not the T-Stat, your water pump has self destructed. The M50 comes with a plastic impeller and in time, fly apart rather spectacularely, depositing bits of itself throughout the cooling system.

A T-stat is cheap, you might as well replace it. If you don't want to, pull it out of a cold motor, stick it into a pot of water and boil it. You should see it open (cylinder expand) as the temperature rises (close to boiling).

Also, overheating it this badly this often, I would perform a compression check. You could have warped the head or cracked the block. When you change the coolant (as you'll have to if you change the water pump, or top up if you change the T stat), check for oil in the coolant, and vice versa, when you do your next oil change, watch for white soapy crap in the oil.

Gamite
03-26-2006, 08:24 PM
yea, plastic impeller's breaking are a common problem.

fob
03-26-2006, 11:01 PM
I've just took back my car home from where it was parked and this time it did not overheat. So I guess the thermostat is defective. Does the local auto parts store carry these parts or I will have to buy it from the stealers.