Running hot (not fan clutch or bleeding problem)

[E30King]

I tested the aux fan. The radiator is less than a year old. Replaced it myself as the old plastic one had cracked. The thermostat was changed about 3 months after the radiator. It had failed and was stuck in the open position. Got the 88deg thermostat installed. Did that myself as well. Had to bleed the system several times on both occasions to get all the air out. Checked the bleed screw this evening and it's in good condition.

Whilst driving home today the temp needle creeped past the halfway mark again and kept on going. Turned on the heater full blast for about a minute. This got the temp needle back down to the middle of the temp gauge and it stayed there for the rest of the 15min drive back home.

Will check the fan clutch... will update with the results of that.

Just wanted to let you know that today I replaced my thermostat on my 318iC with something a little different. I presume the one I had before, was opening up way too late to the point where the temperature can be ridiculous at times. Anyways, my new one is now running at middle and less.

Maybe your temperature hasn't changed from the thermostat you got; 88deg? I put one with 80 degrees. After you try the clutch fan, and it still isn't any better, take the thermostat and exchange it with something less. Possibly that 8 degree difference does make a difference.

[Carib]

Tested the fan clutch. I was able to stop the fan from spinning with the engine hot and even when revved up. Replaced it yesterday. Dropped the wife to work today and on the way there, the temp gauge was stuck at the halfway mark. Coming back home, the temp needle shifted slight to the right of the half way mark and stayed there. The outside temp was only about 15degrees celcius and there was minimal traffic. Going to keep an eye on it for the next few days and see how it goes.

[DesktopDave]

Let's hope it stays fixed...good to hear!

[Carib]

Update: Changing the fan clutch worked. Temp guage shows the engine running at a constant temperature during long drives. Went on two +600km trips within a week and the temp guage was rock steady in the middle while cruising and shifted a hair's width to the right, if any at all, when working the engine hard going up lo-o-o-o-ong hills. The same happens when sitting in heavy traffic for more than a few minutes at a time.

All in all, I'm satisfied the new fan clutch solved the problem.
:-)

[DesktopDave]

Excellent!  Thanks for posting the solution.  The M42 is very intolerant of overheating - any assistance with this problem is very important.

Makes me think I should test out my spare fan clutches...wonder if the oven would work?