I have a 1989 BMW318i, and the engine temp wouldn't warm up all the way so I changed the thermostat. After changing the thermostat (testing the thermostat prior to installation) I started the car and to my dismay I watched the temp rise to the red and I had to shut it off. My question has to do with the bolt on the thermostat housing, is that there to bleed the thermostat? Someone told me that's what that is for, but I want to get someone else's opinion. Do you have to bleed the cooling system (the bolt on the thermostat housing) after a thermostat change? Please HELP!!!

sincerely,

Whiteb

If it is an 8 mm bolt with a little hole under it,yes,that is a bleeder.You must bleed the system of all air or it will over heat in short order.

Bleed for me.

I broke off the screw on the previous t-stat housing. It has to be turned counter-clockwise right? The screw was pretty rusty, I'm afraid I might break the screw in the new t-stat housing. Any suggestions?

I broke off the screw on the previous t-stat housing. It has to be turned counter-clockwise right? The screw was pretty rusty, I'm afraid I might break the screw in the new t-stat housing. Any suggestions?

Buy a new housing.

Alex

I fixed it. I didn't see the bleed screw next to the radiator cap. I opened the bleed screw, added water/coolant, and revved up the engine. After a few minutes my heater started blowing hot air and I took it for a spin and the needle never went over the half mark (it stayed right below the whole drive). Thanks for everybodies help

Whiteb