HELP Car Overheating Help

[dr.gonzo]

So i was getting the car aligned yesterday and it began overheating, I already knew the car had a problem when it came to idling for long periods of time. After leaving the shop i was stuck in stop and go and the car pegged all the way right. I let the car coast and it began to cool.
Symptoms:
Heater doesn't always work
Car overheats,
Leaking coolant like crazy (guessing from the reservoir)

[dr.gonzo]

Where is the thermostat located, Im going to try pulling it and venting the system to get the air out?

[Mike325]

If you have an m20 engine, the t stat is located on the front of the engine, right near the top. Here is a picture that I found. You would have to pull that housing apart, it just unbolts.



And since you are leaking coolant, I would also say that that is a significant reason of why you are overheating.

[dr.gonzo]

I was checking out the car more closely tody and realized that I am leaking oil from the valve cover. The car was pegged hot so I am thinking the head is ruined. What's the cheapest I could swap in something other than a m20 for?

[dr.gonzo]

I'm headed to the junkyard today to look for some possible donor cars, what should i be looking for

[dr.gonzo]

The car wasn't leaking oil from there before, I am going to go pull the Tstat and vent and see if that does the trick.

[SpecM]

The car wasn't leaking oil from there before, I am going to go pull the Tstat and vent and see if that does the trick.

don't pull the t-stat... just loosen the the bleeder screw on top of the housing and fill the system with water.

if coolant is bursting out of the reservoir once it gets warm, you may have cracked the head

[PeaveyBassist]

Btw, a used m20 head is not normally $50 lol Not an 'i' head anyways. If coolant is coming from the front of the trans tunnel, there are a lot more places that can leak other than the heater core. First off, the heater core is INSIDE the car so if it is leaking, it would be leaking coolant inside the car, not on the ground. There are a lot of coolant hoses under the intake manifold and TB. Its something you just have to check. There is no way for us to find a coolant leak for you on the internet.

[dr.gonzo]

Oh I'm already aware of that, when I took the Tstat out the thing looked like it was a thousand years old.

[xwill112x]

The car wasn't leaking oil from there before.

what? a bmw that doesn't leak oil? my brain cannot proccess this.

[Vtec?lol]

I don't know about you all but I hate when people post threads asking questions but then posting answers and thought up solutions for themselves.

I think you should take the car to a mechanic. Not to be a jerk but M20 coolant systems are extremely sensitive. Not very complicated but they do have more fail-points than any other bmw. Have it checked by a certified BMW shop. Just replacing your head isn't going to fix your problem.

[87-325ic]

If you want to save this car then redo the cooling system.
First, FIND YOUR LEAK. you are obviously leaking fluid from at least one place. find out where.,
Second. Fix that.

Next, replace worn hoses, the thermostat, water pump and probably timing belt, and most likely fan clutch. And be sure to thoroughly flush the block and radiator out.

Hopefully you havent ruined the head yet. good luck.

[dr.gonzo]

Well the leak needs to be fixed but here is a update thus far.
I ran the car without a t stat all day pretty hard and the car didn't begin to overheat until I got into stop and go (which is the same problem I had in my NA miata and that turned out to be a radiator) The fans are all working so I am starting to think that it is the radiator. I do need to find the coolant leak (still trying to find where to go get it tested) I have more or less decided to say eff the head and go do a m30 swap. I am losing my license for a year (no not a dui and not my fault) If I don't have the car it won't be that huge of a deal.

[Naplm00]

here is random question...did you check your clutch fan?

When it goes bad it will not cool the engine and cause an overheat, esp when sitting and idleing

[87-325ic]

all you have to do is find and fix your leak.

then replace the t stat, and flush the system really good. and probably replace your fan clutch. and youll be in great shape (if you havent already ruined anything)