M20 Cooling System Trouble

[Black0ut07]

I already searched, searched, and searched some more. My car is overheating to the 3/4 mark at idle and when sitting in traffic only. When I'm moving or revving it while stopped the needle goes back to the middle. I just replaced the fan clutch today but I still have the same problem. This weekend I'm going to change the thermostat and bleed the system to see if that helps.

The other issue is that when I turn the car off, steam spurts from the top of the expansion tank for a minute or two. Also the coolant level warning comes on but when I let the car cool and open the expansion tank I still have the proper amount of coolant??? What do you guys suggest at this point?

Lastly, my A/C doesn't blow cold but I figured I needed to recharge it, but I noticed today that the heat doesn't blow hot either -_-

[autobahnjim]

head gasket or cracked head,..............going through this as well. trying to find another 885 head casting that isnt trashed.....

[ChiTownTy]

Check your fan clutch. Do a coolant flush and go from there. How many miles on the motor?

[Black0ut07]

We did the fan clutch today. Motor has 180xxx on it. I really hope it isn't the head gasket but if it is I guess it's time for a full overhaul and tune up.

[racingwoody]

When was the last time the water pump was replaced, is it circulating enough coolant through the system? Is your electric fan working, it should kick on when the engine temp gets to hot and push extra air through the radiator when standing still. Still swap out your thermo, but if when moving the temp is good then the thermo is probably working properly just not enough circulation of fluid when standing still. Also the m20 has a pressurized cooling system, the expansion tank cap should have a 3 bar cap on it (I think). If the cap went bad it will not hold pressure (steam will come out) and the system will not circulate properly when standing still. If you swapped the cap from an older m20 motor from an 87 or earlier e30 or something the reservoir caps have a different pressure rating. I would look into all of these minor fixes before head gasket replacement.

[Black0ut07]

Awesome thanks for the help! Also my A/C doesn't blow cold but I figured I needed to recharge it, but I noticed today that the heat doesn't blow hot either. Looks like my entire cooling system wants attention ( I even replaced the blower motor sword thing the other day -_-)