SL/R129: 1994 SL320 Overheating 230,000 miles
Thread Starter
Newbie
Joined: Apr 2023
Posts: 7
Likes: 1
1994 SL320
1994 SL320 Overheating 230,000 miles
My engine temp slowly rises to just below redline and holds there. If I turn on the defrost on hot, it brings the temp down 5 degrees. I have replaced the thermostat and the fan clutch. When I turn the car off, the temp drops right away instead of rising? The car seems to run fine, just hot. The radiator looks like new. I do lose a little coolant out the radiator cap overflow. My overflow hose from the radiator cap is bad and it leaks there. Where does that hose go to?
Does anyone have any suggestions about what I should try next? Big Foot !!
Does anyone have any suggestions about what I should try next? Big Foot !!
Member
Joined: Aug 2007
Posts: 76
Likes: 7
One thing I don’t see you mention is the electric cooling fans, there are two mounted in front of the radiator. One runs via thermostat and one runs when the AC is on (also defrost) check that both are operating properly, they will run together if needed fuses/relays are driver side near the A-pillar. And some of them are located below the fuse box cover, 4-screws to access if my memory works. Best of luck keep driving it.
Thread Starter
Newbie
Joined: Apr 2023
Posts: 7
Likes: 1
1994 SL320
Thanks. I think they are ok? They do both come on. I noticed that if I kill the engine and leave the key on, after 30 seconds both fans kick in and stay on till I turn the key off.
I am afraid to drive the car with it running hot. It runs fine and doesn't boil, but I am afraid of damaging a head gasket running it that hot????
I am afraid to drive the car with it running hot. It runs fine and doesn't boil, but I am afraid of damaging a head gasket running it that hot????
