Over Cooling

[doogie]

OK... had this problem for a while but until very recently didn't kow it was a problem......

My temp gauge has never normally read 12 o'clock since I got the car, normally it only goes up 1/4 of the way.

I have had the stat that the car came with, I have drilled this to help bleeding, I have put in a new (non genuine) stat which I drilled to help with bleeding, and with all of these, the stat only goes up 1/4 way during normal driving.

Today I had the car idling for a while (I actually also had the electrics disconnected from the heater valve because I was trying to work out if it was related to this because I also have a problem that I get no heat from the middle blowers, but heat from the windshield and floor blowers,) and the temp gauge went up to 1/2 way, but as soon as I started driving again, it went back down to 1/4 way.

I know I could try putting some cardboard infront of the radiator (!) and I'm now thinking about changing the stat again.... I could get one from the stealer for £23 or one from Halfords (like the one I bought the other day) for £11.20...... if that will definetley solve my problem, then I'll happily change the stat again to the stealer part, but if it's just an iffy/maybe then it's probably not worth it as I've already just changed it.

[Tiger]

The reason it never go half way because you drilled the hole. Someone did this on a MB and the temperature gauge would always read very cool... until I change it again with no hole and it is back to normal.

That little hole makes the big difference in temp control because it allows hot coolant to escape to radiator when it is not supposed to. And because of extended idling, the temperature stabilized itself. As usual, when you start to drive again, too cold.

You are wasting too much gas due to cool engine.

[632 Regal]

part stores. BMA sells BMW stats and so does my local foreign part place. The BMW one has a hole in it but it has a check ball deal on it. Some after market stats plain suck, if it dont seat completely just a hairline gap it will allow enough fluid to travel through and not heat up correctly.

[George Davis]

I'd suspect the gauge or sender. Find somebody with an infra-red thermometer and check the temp on your upper rad hose when the gauge is showing 1/4 to see what it's really going on.

[Tiger]

He said if extended idle, then 1/2 way mark. Seriously... a hole in thermostat will affect the operating temperature greatly. One tiny 1/8" hole is about 10 degree difference.

[632 Regal]

too.

[doogie]

Tomorrow I'll pull the stat and bung the hole (duck tape!) and I'll put hylomar instant gasket stuff round the new o-ring and the inside of the stat housing to try and get it as sealed as possible and see if that makes any difference.

[Tiger]

Try a very short screw if possible or a rivet.