The complete automotive resource for buyers, sellers, and owners like you.
Car, Truck and SUV Forums at Roadfly
+ Bentley Forums
+ BMW Forums
+ Cadillac Forums
+ Chevrolet Forums
+ Ferrari Forums
+ Jaguar Forums
+ Lamborghini Forums
+ Lotus Forums
+ Mercedes-Benz Forums
+ Maserati Forums
+ MINI Forums
+ Porsche Forums
+ General Discussion
+ Marketplace Forums
Re: Still running hot... (archive)
[ Follow Ups ] [ M5 (E28) Message Board ] [ Msg. Board FAQ ]
Posted by Lamar Hawkins on September 07, 2001 at 10:39:11:

In Reply to: Still running hot... posted by Sean on August 27, 2001 at 21:30:50:

Hi, Sean.

I just saw your 8/27/2001 post to the E28 M5 message board and all the replies. Is your M5 still running hot?

My temperature gauge usually never registers more than halfway. However, last summer I noticed it going past the halfway point, but only when I was waiting in a drive-up line at my bank on a hot day.

Anyway, I had the M5 in the shop one day and I told my mechanic what was going on. The first thing he did was check to see if the auxiliary cooling fan was running (something I was clueless about at the time). He said the aux fan should always be running when the A/C is on. Mine was not. He quickly diagnosed the problem and it turned out that the aux fan ballast resistor (the small rectangular plastic-looking piece mounted on the aux fan housing and visible through the front grill) had gone bad. So, I picked up a new resistor at my dealer and was able to replace it myself.

When I pulled the aux fan housing (this is the only was to get to the screws that attach the wires to the resistor), I found a large clump of debris in the condenser fins behind where the center of the fan rests. Obviously, I cleaned out the debris, replaced the resistor and the aux fan now works correctly.

Just prior to replacing the aux fan resistor, I had all except two of the coolant hoses replaced along with the thermostat and all the O-rings and nozzles and such in the thermostat housing. The radiator and upper and lower radiator hoses were replaced not too long before I bought the M5 in December of 1999.

So, guess what. After doing all that work, the M5 still runs at about the same temperature as before, which really isn't a problem. The only thing I haven't done is to renew the coolant and I'm about to do that.

Regards,



Replaced the fan clutch and it didn't seem to have any effect. It does feel a little more firm than the one I replaced, but was apparently not the culprit as the car is still running hot at slow speeds. I guess the thermostat is next. Any other suggestions?

Thanks.

Sean
'88 M5
'76 2002




Follow Ups:


[ Follow Ups ] [ M5 (E28) Message Board ] [ Msg. Board FAQ ]
Questions, comments, or problems, please visit the Roadfly help desk.
Roadfly.com Logo © 1997 - 2009 Jump Internet Inc. All rights reserved.