Over heating!!!

[Rkcstllns]

Ok so I just bought my car a few weeks ago and I barely get to drive it. But when I drove it home I noticed that the temp on the gauge was fine, at about half way. But as soon as I got on the streets it started to creep up. I got home before it got too hot and parked it. The next day I take it to a friends house and the gauge barely even moved off of the cold side. I replaced my timing belt water pump thermostat and other items as preventative maintenance. And now the car over heats unless I turn the heater on. Any ideas? It's an 89 325i coupe.

[yert315]

did you bleed the system thoroughly?

[Rkcstllns]

I'm supposed to jack the car up turn the heater on and run it right? Will not bleeding the system right cause it to over heat that quick? My friends house is 2 miles away tops.

[HR2L]

Sounds like you need to bleed the system a little bit more.

[yert315]

Jack car up. Run car with heater on. Crack bleeder screw until no bubbles come out.

Sometimes it takes time to get it all out.

And yes, air in the system will cause it to heat up quick.

[jlevie]

A possible clue here is the observation of the engine running hot when the car was being driven slowly. That is usually a sign of a bad fan clutch. If the pattern is still the same, replace the fan clutch.

To bleed the system:

1) Using ramps or a jack get the front of the car 1' or more higher than
the rear. That will make the radiator and bleed screw the highest point
on the engine and facilitate removal of air.

2) With the bleed screw open, add coolant until no more air comes out of
the bleed.

3) Leave the filler cap off, or at least loose, and set the heat for max
temp and fan speed. Leaving the cap loose will prevent air that's still
in the system from causing a "coolant fountain" once the engine heats
up. Start the engine and allow it to warm up to operating temp. As it
warms up occasionally crack the bleed screw to release any air and top
up the coolant as necessary.

4) Once the engine is at temp bring it up to 2000-2500rpm for a few seconds
several times. Then crack the bleed until no more air is released. At
this point the heater should be throwing lots of hot air, which
indicates that the heater core is filled with coolant. You may have to
repeat this a few times to get all the air out.

5) Drive the car a bit, allow it to cool back down, and recheck the
bleed for air. Over the next few days you may get very small amounts (a
few bubbles) of air out of the bleed screw.

[Rkcstllns]

Quick question, where is this damn bleeder screw?

[Rkcstllns]

I have the system with the overflow separate from the radiator, I read somewhere that these systems are self bleeding, Is that true? Does this mean my problem isn't that I haven't bled it right?

Thank you guys for your help

[z122643]

The bleeder screw is directly on top of the thermostat housing.

[MR 325]

R3V does things the hard way, I swear. I can bleed a car without running it and without it being hot in about 2 minutes. I should probably make an instructional video. (Oh yeah, no ramps needed either).

[StereoInstaller1]

If you have a stock M20 cooling system, don't jack it up.

if you jack it up, the bubbles will go to the highest point...which is the radiator.

Leave it on the ground and use the bleeder screw.

[accident]

R3V does things the hard way, I swear. I can bleed a car without running it and without it being hot in about 2 minutes. I should probably make an instructional video. (Oh yeah, no ramps needed either).

Would be interested in this information.

[Rkcstllns]

Ok that's where I thought it was, I guess the po messed it all up last time he did the timing belt, because it's all rounded off and I can't get it to open.

[accident]

Vice grips work great on stripped bleeder screws

[Rkcstllns]

^^exactly what was thinking