Coolant temp and Cool Harness (c)
 

My 420SEL normally runs failry cool. The temp in my daughter's 300TE, however, had a tendency to shoot up, especially in stop and go traffic.

I did three things to help lower temps....

1. Lowered the coolant/water mix ratio to 40/60;

2. Added WaterWetter; and

3. Bought and installed a Cool Harness (c) designed, made and sold by our own JimF.

Yesterday I drove in the San Fernando Valley, where temps were in the hundreds.

The lower coolant content plus the WaterWetter helped keep coolant temps low. Whenever the temps creeped north of 90 degrees, the CH would kick in, helping to cool the engine. Even while waiting at the In and Out drive-through, the temp never shot past 95 degrees, even when ambient temps were in triple digits.

Good product JimF....it works as advertised.....

PS I also bought one CH for my 420SEL, but the W126 engines seem to run cooler than the W124, or they have a better cooling system...


If you are having cooling issues, check your coolant/water ratio and see what happens....

You can also...
 

try a new thermostat. Although, probably you already done that.:cool: