Overheating

Hi, I have a 1990 535i i am trying to get it back on the road, I recently changed the spark plug wires and it runs a lot better, and also changed the water pump due over heating, and found out that it didnt have a thermostat i put one in and i am still having the same problem it stills keeps overheating the gauge moves quickly to the red, i am stuck dont know what else to do, if any one has suggestions or been through this let me know what to do, before i have to take to a shop..

How did you bleed your coolant system after the water pump install?

+1 need to bleed the system. really easy to do on the 535 based on first hand experience let us know if you need help

+2 on bleeding.

If, after you know that you have bled the cooling system properly, you still overheat, then you need to investigate to see if you have a blown head gasket. Look for milky looking oil, oil in the coolant, and the for the most definitive diagnostic test, do a compression test.

Hope it's not a blown HG.

Good luck,
Steve

First of all how do you bleed the system correctley, and i did check the oil and their is no residue or anything different, i followed what the chiltons book said how to bleed the system i filled the with antifreeze into the tank against the firewall and then turn on the car and opened the bleeder valve i had steam coming out first then some antifreeze, but the gauge still moved up really quick to the middle then shortly after it got to close to the red, so let me know what you guys suggest for me to do.

i find it helps to raise the front of the car to get the air out and it can take a couple of tries. you should also have the heater on full. leave the breather open until you get a very steady flow of coolant and then close it. after another try or two you should have purged all the air out of the system. it can take 20 twenty minutes of running before you get the desired result.

witch is the correct way for the thermostat to go in i put in with the spring towards the front.

I think something's not right if a mere case of insufficient bleeding can be responsible for the car overheating like this regularly. I think he has other problems. In any case, try this on for size. Keep pouring water into the tank with the bleeder valve open. Say 1 gallon extra. Let it overflow like mad. It will flush water through the system and force out all of the air bubbles. Do this with the engine switched on too, another 1 gallon. Then pour in some cheap coolant from the gas station, and screw the bleed screw and tank cap back. Any remaining bubbles would be too insignificant to matter. Make sure you're doing this with a friend who can warn you when the temperature is reaching the red zone. This should sort out your bleeding issues and eliminate that as a possibility in this mystery...

Thanks everyone for you help on get my bmw back on the road it been working great and the heating issue has been resolved had to bleed the system a couple of times. Thanks again everyone.

Originally Posted by Junior76

Thanks everyone for you help on get my bmw back on the road it been working great and the heating issue has been resolved had to bleed the system a couple of times. Thanks again everyone.

Glad it was that simple. It did sound like it just needed to be bled properly and fortunately, that's all it was. It's a bear to get it done properly sometimes.

Steve