Roadfly Home | Features | Car Review Videos | Car Reviews | Cars For Sale | Used Car Parts Classifieds | Forum | Car Review Archives | Forum Archives Index


09-29-2004, 09:02 PM
For months now my car has been consuming coolant like a mad man.

The temp guages for water and oil always look normal.

The underside of the passenger side of the car is where I find coolant pooling and Ive discovered that coolant is always comming out of the vent hose that goes into the chassis.

After a drive tonight I parked and noticed that coolant was continuously flowing into the overflow tank, and that some had been vented onto the chassis (...sigh)

I also noticed white smoke under hard acceleration this evening.

I checked the oil dipstick for any sign / smell of coolant but it looked fine.

Ideas anyone?

09-29-2004, 10:48 PM
warped head.

Time to pull the head (I did it last night in 2.5 hours) and get it checked for straightness. Have to change the head gasket while you are in there.

09-29-2004, 11:12 PM
Over pressurization of the cooling system. When the system is pushed over 20 psi, coolant is forced out of the overflow hose.

How does the system overpressurize, couple of ways, blocked hoses/cooling passages for one - these typically show up in overheating which which also raises pressure. The big one however is leaking head gasket or cracked head. Based on your description (not overheating, white smoke), that is my bet.

I would do a leak down test on your coolant system and see if it holds pressure to spec. If not, most likely you have a head gasket issue.

You can also confirm by doing used oil analysis - if it is bad enough, you'll see actual coolant. If not, you may see a coolant signature.

Good luck.

09-29-2004, 11:51 PM
Thanks guys! Here is more Ramble

After the engine cooled I noticed a larger pool of coolant, and a significantly lower coolant level. I looked for any traces of coolant in the oil(again), visually and by scent. IMHO oil looks okay. Exhaust is stinky but not coolant. My earlier observation of white smoke really turned out to be just heavy smoke under hard accel. (borla and VSR center)
Took her for a short stint and then the Coolant Idiot light came on. Smell from the engnine of burning coolant, from what i believe is from all sorts of overspray from that vent hose!

The car Just passed 84k , 400mi in the past 2wk but only about 2500 this year. Been leaking coolant the entire year, came about after the winter some time.

Drives really strong and feels solid as ever...

Again Thanks for the input!


09-30-2004, 02:50 AM
...both. The tank and cap may not be holding enough pressure. My M3 was also leaking out the vent when I bought it. I changed the cap first, but that didn't do it. I found that the plastic lip that holds the cap was distorted on the expansion tank. That prevented the spring in the cap from compressing enough. Once I changed the tank, I had no more problems.John
88 ///M3 Cinnabar
84 318i Black

:: Mick ::
09-30-2004, 07:26 AM

Roadfly Home | Car Reviews | Forum Archives Index