Heater blows hot only at higher rpm

[sepehr]

I tried changing the thermostat, but that didnt change anything.

Is my heater core clogged? Can it be cleared with a garden hose?

Thanks

[PeaveyBassist]

Try bleeding the cooling system. I had a similar problem. Only had heat when not at idle and with the fan speed on at least 2. I drained the radiator and block and changed the thermostat. Put new coolant in and bleed it. Fixed the problem.

Will

[AdamF 88iS]

You have an air bubble. You need to bleed it.

[325ise30]

I think he means the blower motor only works on high, in that case it would be the blower resister.

[Dave]

My vote is that you have an air bubble.

And BTW, I thought Heater discussions were forbidden now? ;-)

[sepehr]

I bled the system from the top of the radiator. Is there any other bleed valves I'm missing? The coolant looked like it had no bubbles when it was coming out of the valve. Are there any tricks in bleeding the system?

I had a reputable shop in here in town (Nixon Automotive) take a look at it. I got them to look at it, and give it a flush.

They say the bottom of the radiator stays cool. What does this mean?

Thanks for the input. I really need to get the damn thing working, moving to Regina Saskatechewan next month!

[PeaveyBassist]

What car is this??? AFAIK The only spot to bleed a 325 (m20) e30 is at the thermostat housing with the 8mm bolt on top.

Will

[sepehr]

Its a 91 318is

[bebes2k]

You need to get a new car sepehr, it's not worth fixing the heater.