m42 overheating?

[keada714]

Hey guys,

I'm new to the forum and would like to get some insight to whats going on with my car and hopefully fix it. Recently I bought a 318is and the car temp was at the 1/4 mark. So I decided to replace the thermostat and flush the system. I found out the thermostat was not there so I bought one. The thermostat was rated at 87 degrees. I pop it in and bled the system, hope I did it right. I pretty much turned the heater on without turning the car on. Open the bleeder bolt and pour my 50/50 coolant in there until there was coolant coming out of the bleeder screw with no bubbles. Put everything back and let the car warm up.

It warms up to over the 3/4 mark and that worries me a bit. Take it for a spin the temp stays between the 1/2 and 3/4. I'm not sure what the problem is. Could it be a faulty water pump (hope not)? I bought the car a week ago and haven't drove it at all. Would like to get it working so I can drive to work instead of always biking 35 miles in the blazing hot sun :). Any recommendation would be great! Thanks in advance!

I also have a really high idle.. around 1100. I already put in a new ICV and deleted a lot of the unnecessary vacuum hose..

[Ryann]

My temp. has been identical to what you're describing since I replaced my thermostat with a brand new Behr 88C (which I'm beginning to think is a POS). Only difference being occasionally my temp will rise to dead on midway and stay there. I don't think the stat is always opening fully because when I feel my upper/lower rad hoses there is too big a difference in temperature.

[keada714]

My temp. has been identical to what you're describing since I replaced my thermostat with a brand new Behr 88C (which I'm beginning to think is a POS). Only difference being occasionally my temp will rise to dead on midway and stay there. I don't think the stat is always opening fully because when I feel my upper/lower rad hoses there is too big a difference in temperature.

Isn't the half mark where the normal operating temperature should be? I hate not knowing what is wrong with my cars... Makes me want to continue to work and work at it even though I can't see a damn thing outside haha...

[selturk]

maybe you installed the thermostat backwards..

[Balleristic31]

Might be a bad gauge ground

[Ryann]

^I considered this as well. I'm pretty sure it's the T-stat though.

[bmwm42]

You need to bleed the bitch multiple times

[Eecen]

Doubt the problem is your water pump.

Does the car have AC/aux fan?
Do you have the fan shroud installed?

Sounds like you bled it correctly, but doing it again couldn't hurt. Try holding the throttle open w/ your finger while bleeding to help churn up the coolant a bit more.

How long was the drive you took after warming it up?

[KenC]

The M42 is a total PITA to bleed fully. Sounds like you have an air bubble.

You can't bleed it properly without the car being on and fully warmed up. You need the thermostat to be open.

[tonywonder]

what ken said. you gotta bleed after its warmed up. thats when you are suppose to top it off.

not immediately though. the coolant will burst out from the temp so wait a little and slowly open the cap to relieve some pressure. when its cool enough you can top it off.

[keada714]

Thanks for the response guys. Yes the car has AC not sure about the aux fan.. Where can I check out the main grounds? Also I bled the system while it is fully warm and driven. I opened the cap and bleeder screw. A bunch of coolant flows out of the bleeder screw without any bubbles (air). then I thighten the bleeder screw and top of the coolant and the car is still over heating. Mostly when i'm idling. The car temp is in between the half and third mark when driving. Once i stop and let it idle for a bit it increases to over 3/4. When I also rev the car around 3-5k the temp drops to around where it is when i'm driving it. I'm pretty sure I put the thermostat in correctly. I placed the spring part of it into the block. Any other suggestion.. Really need to get this car rolling.. It was 90 + degrees...

[KenC]

I still think you have an air bubble.

Jack the front of the car up while you're bleeding it.


Did you mess with the lines into the firewall/heatercore at all?

[Nairb]

I was having all these same problems.

I bought a new radiator, a lot of my problems went away.

[tonywonder]

check to see your clutch fan is good newspaper trick. check your aux fan is working by pressing the AC switch. should turn on with that switch on. if it does turn on make sure your temp switch on the side of the radiator is good. if not check all aux fan related fuses.

check to see if there are any leaks under the car and anywhere on the radiator. and if the coolant level is the same after running it. if u did the mess under the intake cleanup make sure you routed the heater hoses correctly (the two hoses that go to the firewall then into the heatercore)

the longer you let it run hot the more likely other things are to fail. happened to me. i just ended up redoing the coolant system.

[keada714]

What I pretty much did to that vaccum liens was remove the whole spider hose.. Then I took a heater hose from the valve cover to the intake. Also the put in a new heater hose from the intake manifold to the ICV and to the intake. I also connect the coolant line for the intake cooler thing. Would the ICV cause the car to heat up. Also how do I know if i have a aux fan? The only fan I see is the clutch fan..