Hi, I have an e36 325i with an s50 engine which I'm preparing as a drift car. After playing with the car at high rpms, I heard a pop from the engine bay. I immediately turned the car off and gave it a visual inspection. There was no liquids leaking and the car still had oil and coolant. A few days later, I let the car idle for a bit to see if I could find the problem but the car stayed at proper temperature. Another few days past and I decided to take it out. After a few blocks, the car started overheating again. Thinking it was the water pump, I took it off today but the impeller was still intact.. Any ideas what could be causing the overheating? There was no white smoke out of the tailpipes when the pop happened. I filled the coolant not too long before taking the car out before the incident. Could I have overfilled it and improperly bled the system? Any help would be greatly appreciated.
I noticed that the coolant hasnt been ciculating through the system, so I think you're right. Although, I just took the thermostat out and it doesnt seem like it's been stuck closed or anything. I can press on the spring for it to open. Are there any other visual signs of a broken thermostat now that it's out of the car? I have an upgraded aluminum housing, so I don't think it's that
Chuck it in a cup of boiling water and see if it opens. Are you running an s50 rad with expansion bottle?
Just tried the boiling water trick... sadly the thermostat opened... Starting to fear that it's a head gasket. Wouldn't the coolant still be flowing if it was though? Yea, I believe its an s50 rad with the expansion bottle Anything else I should check for? I'm out of ideas
Heater core connection in a 36 is oring sealed potentially an air pocket in there has popped the plastic housing or oring. Need to pull the centre piece of the slam panel out and you'll see the 10mm holding it on. Try get a hold of a pressure test kit and pressurise the system that'll show any leaks. Also did you remove the valves in the heater core pipework?
I think i found the issue. I was trying to bleed it some more and noticed that steam was coming off the heater control valve. It seems like it disconnected between the top two ports and the bottom 1 {}