M52 running hot?

[85bim]

I have an M52 in my car with an E36 318 radiator (the one with the overflow attached). The car runs at about 215 -220 deg F with the heater off. With the heater on it drops down to just above 200.

It has a new radiator and new 180' thermostat. I thought I was just not getting it bled correctly so I took it to a local BMW shop and they tested everything and pressure bled the cooling system. And said it checked out fine...

Any ideas????

[justin_l_]

Too small of a radiator. Add a little water wetter and a good fan, you should be able to keep it under control then.

[matthugie]

Do you have a fan? I'm running the same setup with a 16" SPAL pusher and haven't had any issues.

[85bim]

Justin you are awesome! I forgot I put water wetter in when I first did the swap! Thant should bring my temp down.

And yes I too have a 16" SPAL Pusher fan, love those things!

Thanks guys

[85bim]

OK so still overheating....

The problem seems to be that the thermostat doesnt want to open. I can drive around for 20-30 min and the lower hose is stone cold...

Any more ideas?

[e30rapidic]

The problem seems to be that the thermostat doesnt want to open.

;-)

[85bim]

But why is that? I just replaced the thermostat and nothing changed...

[ParsedOut]

Air in the lines is more likely.

Here's what I do to bleed M5x.

Drill 1/16" hole in the thermostat.

Fill radiator through the upper radiator hose, then fill through expansion tank.

Lift the front of the car and let idle until up to operating temp, all the while massaging the upper radiator hose to push the air through the previously mentioned hole.

*This part is optional and not usually required, but will help with stubborn trapped air. Then let it cool down so the upper radiator hose is still very warm, not so much to burn you but it shouldn't be comfortable to hold onto it for very long. Then you loosen the upper radiator hose at the thermostat, just very slightly loosen while listening for any suction or whoosh sound before coolant starts to push out, tighten back up as soon as you see coolant.

Let cool the rest of the way, top off the expansion tank and you should be good.

Check the expansion tank a few more times throughout the week and keep it at the appropriate level.

[e30rapidic]

I had to drill a hole in mine as well, as it was a bugger to bleed. If I am remembering correctly, the hole should be at the 12 o'clock position when you put the thermostat back in.

[85bim]

Thanks for all the ideas, the shop determined that everything is working fine and I just have a bad temp gauge. Lets hope thats correct since the Leavenworth drive is this Saturday!