help... coolant leaking from expansion tank cap

[shhuang]

drove to dining hall today to get food only to come out and see coolant all over the parking lot. pop the engine and its coming out of my expansion tank cap... hmm cap is a little loose, tighten and drive off. i live ~5 miles from campus, and halfway home i notice engine temp at red... drive gently the rest of the way home, w/ heat on full blast, heat isn't very warm, kind of cold, get home, car is now parked.

im gonna refill with distlled water and bleed and see if it holds pressure and temps don't rise... any ideas what went wrong? maybe my expansion cap was loose? air in my system? help... just finished overhauling suspension and now this..

[shhuang]

also... just noticed that the lower radiator hose is cold. thermostat stuck closed? did this cause the coolant to boil out of the expansion cap?

[jimmiwin]

I've had coolant issues lately. Long story short...if you have any miles on your thermostat, change it. I'm attributing that to my bursting expansion tank and the only time I've ever overheated. Flush and bleed the coolant. Make sure it's bled well as an air pocket will cause the heater to not feel warm.

[shhuang]

hmm, i just installed an 80c thermostat last year from understeer.com's fan delete kit. while i was installing it though, my idiot roommate manages to de-latch the spring on the thermostat; we put it back together though and it has been ok up until now, maybe... any help out there!$?@$

[Crazy Dave]

drove to dining hall today to get food only to come out and see coolant all over the parking lot. pop the engine and its coming out of my expansion tank cap... hmm cap is a little loose, tighten and drive off. i live ~5 miles from campus, and halfway home i notice engine temp at red... drive gently the rest of the way home, w/ heat on full blast, heat isn't very warm, kind of cold, get home, car is now parked.

im gonna refill with distlled water and bleed and see if it holds pressure and temps don't rise... any ideas what went wrong? maybe my expansion cap was loose? air in my system? help... just finished overhauling suspension and now this..

I know some cars had problems with the caps...so definitely try picking up a new one. A good thing too, anything that hasnt been replaced in your cooling system, replace it. Its bound to go out.

[shhuang]

meh fixed it, was thermostat stuck closed.

[tomas3314]

Same thing happened last year to me. There is actually a recall for most e36 on the radiator cap. (I know there was one for my 92' 325i) You can take it in, they'll do a whole inspection and change your cap for free. I did this last year. They didn't charge me.