overheating

[blaze12]

whats up folks, here's the problem
89 525i only overheats when the the car is in drive and my foot is on the breaks
changed hoses, water pump, aux pump, radaitor, aux fan did compression check
on engine and coolant hoses. when the car overheats i have to put on the heat
to cool the engine . yo it's hot as hell already in the summertime know what i mean. Its relly pissing me and the shop off. any help is thnakfull

[JonE]

Is the fan clutch good, so that when that engine is quite warm the fan in front of the engine is blowing air pretty strong? If not, that fan clutch might be turning/spinning but just "free-wheeling" and not blowing enough air to cool the coolant/engine. This was the problem with my '90 535i recently. Pretty easy fix.

[blaze12]

sorry forgot to say that we changed the fan clutch also.
thanxs

[winfred]

have you gotten the air out of the system? m20 525s are a bitch to get to burp, i've done a few head jobs on cars that people have roasted the motor trying to get the thermostat to open, one thing that helps get rid of the air pocket is to drill a 1/16 or so hole in the thermostat to break the vacuum and let the block fill up

[ocampg]

have you gotten the air out of the system? m20 525s are a bitch to get to burp, i've done a few head jobs on cars that people have roasted the motor trying to get the thermostat to open, one thing that helps get rid of the air pocket is to drill a 1/16 or so hole in the thermostat to break the vacuum and let the block fill up

I might be having that problem with my M20, where exactly do I drill the hole?

[JonE]

This is from Bruno's site:
• When doing the thermostat the arrow on it needs to be pointing straight up and if you want to make the job of bleeding easier drill a 1/16 hole directly through the thermostat where the arrow is located (tricks from BMW tech's) which allows the thermostat the bleed easier. Trick from LINGLE

[ocampg]

This is from Bruno's site:
• When doing the thermostat the arrow on it needs to be pointing straight up and if you want to make the job of bleeding easier drill a 1/16 hole directly through the thermostat where the arrow is located (tricks from BMW tech's) which allows the thermostat the bleed easier. Trick from LINGLE

unfortunately, i went the cheap route and purchased my thermostat from autozone, anybody have a pic or diagram of where this hole should be drilled?

[blaze12]

i ran a vaccum on the hoses to get the air out then bleed the line for hour and a half. All the hoses were hot . thanks i'll try the hole trick you never know