Overheating problem. Help.
Thread Starter
Junior Member
Joined: Jan 2015
Posts: 27
Likes: 2
S500 w140
Overheating problem. Help.
I've been fighting an overheating issue for some time now on my '92 s420. I've eliminated two items on my own checklist hoping it'll have solved he issue. My temp gauge spikes almost near the 120 mark when in traffic or when you gunning the pedal for an explosive takeoff. Yesterday I replaced the thermostat and the fan clutch hoping that would solve the issue but the gauge is still spiking. Tried bypassing the coolant hoses away from the heating ctrl unit cause I suspected a leak from the unit and figured that might be the cause but that too didn't help. My mind has stalled 
Please share some thoughts on what you may think could be the issue. Thanks guys.
Please share some thoughts on what you may think could be the issue. Thanks guys.
Thread Starter
Junior Member
Joined: Jan 2015
Posts: 27
Likes: 2
S500 w140
I removed the thermostat and ran the car at normal speeds but still the temperature rose to almost 120. Haven't flushed the coolant radiator yet. Planning on doin that today with absolute ridiculous pressure and hope all goes well. If that doesn't help then I'll have completely ran out of ideas
Thread Starter
Junior Member
Joined: Jan 2015
Posts: 27
Likes: 2
S500 w140
I was able to get the problem fixed eventually. My coolant radiator was really dirty and some passages had been slightly constricted thus the high temps when driving fast. Take the radiator for a thorough wash (in and out) and that should sort out the problem. Better yet, buy a new one. Zero the life.
