bklynz00

Please Help.. My MB 97 C280 is running extremely hot while running the AC, and in heavy NYC traffic. The car seems to cool off when it is moving. The Temp. goes in the red and one day almost beyond. Again, this only happens when the AC is running. Any one with advice ?

David C Klasse

Check the thermostat! I'd replace it regardless, it's cheap. I'd also change the coolant.... and do a 60/40 mixture of water/coolant (MB). Have the system flushed and see if there's any clogged spots in the radiator.

systemguide

Check to make sure the fans are working. Seems like when the car is moving it is getting air to the radiator but when sitting in traffic not enough air is heating the radiator to cool it down.

David C Klasse

Yup.... check and make sure that your fans are turning on when the coolant temp reaches 100C, according to the cluster. You should definitly be able to hear them blowing when they turn on.

SLK Boy

My fans turn on, but not for very long...how can I tell if they need to be replaced? I'm still trying to figure out the same overheating problem...the highest it usually gets to is about 115...it never reaches 120, but it gets pretty close...radiator has been replaced, and the thermostat too....could it be a leaking head gasket?

bklynz00

He thanks for the tips, I think I'll make a trip to the local MB dealer and purchase some Anti freeze and a themostat... I'll keep you guys posted !!

bklynz00

SLK Boy

Dont over look your water pump, that could be a problem as well !

BrabusCClass

My Waterpump went out around 80,000 miles. Also some sort of fuse went out that made my car run hot or something. It was to my fan. Check your fuses.

SLK Boy

Oh, the water pump was replaced recently too.. So i'm still wondering why it's getting so hot...if i can't get it fixed, i'm going to get rid of the car soon..

systemguide

I thought your car is over heating. It's not over heating jus running hot. My 95 C280 does the same thing and someone told me it is normal for it to run that hot, but i'm not sure....
Let us know if you get it fixed.

bklynz00

"System-guide" I sure will.. Iam saving up da money now so I can bring my car to the MB dealer for servicing.. lol Iam hoping that your right.. Although, I cant see how it's normal to have the car overheat or get that hot normally while using the AC in stop and go traffic.. That can be dangerous for the engine. It gets hot where I have to cut off the AC and some times put on the heat to get the temp to lower !!

bklynz00

I would like to inform those whom are interested, that I found out what was causing the overheating with my car... The anti-freeze wasnt properly mixed. MB has different mixtures for summer and winter. Summer should be 60% water, and 40% anti-freeze. Once I made the proper change in the anti-freeze, the car didnt reach the 120 red zone as before. Also, I use only MB anti-freeze.

SLK Boy

That's good to hear! I think i'll be doing this soon as well (might as well replace my thermostat while I'm at it). Do you know what the mixture is for the winter? I also have a bottle of Red Line Water Wetter...you think i should bother using it, or just use MB coolant and water?

David C Klasse

Use 60/40 (Water / Coolant) year round! Unless it gets REALLY cold, I wouldn't worry about it.
And sure, throw in the water wetter... I did to mine. I didn't notice anything, but I guess it doesn't work to bring the coolant temps lower, just dissolves "hot spots" or something like that.