[Greg 06'330i]

Got an 06' 330i, manual tran, 52k miles on it. The water temp light came on and the car went into limp mode. I parked it and noticed that the coolant was a little low so I topped it off with some water. Ran ok the next day for about 10 minutes and then it did it again. I parked it, never saw any obvious puddles of coolant anywhere, but it is again low on coolant. Anyone got any ideas? I would like to fix it on my own if possible. Out of warranty. Thanks.

 

[witeshark]

Do you see signs of coolant in the oil or the reverse? It's a bit better to top the coolant with premix of coolant and deinonized water. Are the cooling fans working rightly? With the car at less than operating temp, turning the A/C on should cause the fans to start running immediately.

 

[Greg 06'330i]

Haven't checked the oil yet. Going to though after work. Fans appear to be running ok. AC works and fan kicks on.

 

[k.sidlosky]

Check the oil also can check the rad. cap.
Watch exaust smoke also, feel for water vapor.
Start it up and let it idle for about ten minutes and check the ground for leaks.

Thats all I got...

 

[chet31]

10 minutes might be about how long your car would last before overheating w/ no coolant circulation. Therefore, suspect thermostat or water pump, both are known to fail in our cars.

 

[Onlya1]

10 minutes might be about how long your car would last before overheating w/ no coolant circulation. Therefore, suspect thermostat or water pump, both are known to fail in our cars.

I agree thermostat o water pump.

 

[chet31]

BTW, I have not done either, but many forum members feel these are fairly straightforward DIYs. Some places (EA Tuning?) sell cooling system overhaul kits w/ waterpump, radiator hoses, thermostat, and reservoir, do them all at once and you should be good for another 75K miles. The Stewart water pump is a little more expensive, but has a lifetime warranty. Search forums and you will find detailed DIYs.