Car heating up?

[e30Matt]

My other car ('89 325iA) has some strange problems.

The first thing I noticed is that the heat goes cold as soon as I stop and the engine returns to idle.

And now, when sitting still at a light in Drive, it begins to heat up, and it appears to want to continue climbing past the 3/4 mark, but as soon as it climbs past the 1/2 mark I either shut it off, or do what I've found cures the problem: put it in neutral and bring the engine revs up until it cools back off.

I was driving back from class today and noticed that if I turn the A/C on (kicking on the aux fan) as well as turning the heat on full blast it will about one time out of five cause it to cool back down while rolling.



I added a mixture of 75% antifreeze/coolant and 25% water to it a few days ago, as I was headed up to the mountains and didn't want anything bad happening, and I didn't know the current mixture.

There is a sweet smell when I turn the heat on full blast, but I've looked all over inside for coolant leaks and haven't found any. I figure if the heater core were leaking, I'd know it by now. Any ideas?

[Jonathan M3]

Have you checked the fan clutch?

[e30Matt]

Not yet, I haven't had a chance to get under the hood. I'll give it the rolled up newspaper test.

EDIT: Walked out to the car, there was a fairly good sized puddle (5-6") underneath the plastic undertray beneath the engine. It's dark now, but I may be able to get out and take a look at it... anyone have any clues?

[bddog]

Your obviously heating up from loss of coolant.Hope for a hose problem, but water pumps often leak when they go bad. Fix before a small problem causes a large one from overheating. Good luck. Steve

[e30Matt]

But i'm still within the tolerances as far as coolant level is concerned... would the leak still cause a car with plenty of coolant in it to overheat?

[mikeedler]

did you bleed out the cooling system, it could have some air in it, and that would cause it to puke up some fluid. bleed it out.

[trashcop 80s 80s]

My water pump started leaking about a week before it went out. Do you know when the last time it was changed?

[mph]

I would say its your water pump. My 325ic didn't leak when the water pump went bad. The temp gauge would climb when I was stopped and the heat would stop blowing cold.

I also replaced the thermostat at the sametime. It was under $80 to do it all (no including the coolant though), parts from dealer.