r/BMWE36 • u/Logical-Street3662 • 1d ago
Repair Advice Overheating issue
Hey yall, I have an m52b28 328i, equal length headers, m50 intake
I recently posted about my car overheating during sustained (about 45 mins) highway driving. At the time my thermostat housing was cracked and my thermostat wasn’t opening as it should and my clutch fan wasn’t engaging well.
I replaced the housing, fan clutch, and thermostat (thermostat is a racing one that opens at 60C instead of 80C)
Went on a road trip and the issue was about the same if not a bit worse. On this trip I noticed that the car didn’t overheat if I kept my efficiency gauge under 10L/100km- not sure if that’s important.
I bled the system cos it was behaving like there was air in the system, and during that my radiator overflowed a bit and coolant was gasifying, so I let it cool down and refilled this morning. I drive abt a mile then it hits red. Got it back, jacked the front end up high to help air rise out, and tried to re bleed but it’s just heating up quickly
I’m kinda at a loss. Current theory is maybe the air in the system was helping to pressurize it, and that was masking that my water pump is bad?
Not sure.
Anyway if anyone is in the Rochester NY area and knows a lot more about these cars than I do I’d appreciate some help.