You seem to have 2 problems - see below for discussion of low speed fan circuit - fuse blown could be an issue.

For the loss of power - there are many other posts that discuss this - basically the computer will shut down some injectors due to detecting spark knock - need to check plugs, wires, coils ect. - some hints:
1) Do Not use platinum Plugs - recommended are the original copper plugs - non-resistor if you can find them - need replacing about every 30k I am told
2) Check or replace the wires - try first the conectors from the coil directly to the plug below it.
3) Look up wiring harness issues and see if your engine wiring harness is failing - plastic will be brittle and falling apart - has been a problem on some models


Hi everyone! Just an update - I have a 1995 C280 with only 63k miles and have been having the same coolant temp problems since I purchased the car a year ago. I went through all of the normal updates: new thermostat, flush and drain, even purchased from JimF the "cool harness" - but the real symptom never changed.

There was another post where someone mentioned that in the low speed fan circuit for his 1994 C220 - there was a relay that controled this circuit in the section "behind" the fuse box on the drivers side of the engine compartment. This relay has a "piggy-back" fuse installed at the factory as a 15A fuse. The indication was that the fans draw over 20A at times and that a 25A or 30A fuse should be placed here.

When I looked - that was my problem - a simple fuse replacement would have solved the problem.

Here are the symptoms:
1) At some temp the low speed fan circuit should turn on the fans and they should run continuously until the temp gets low enough to turn them off - or - the high speed circuit kicks in.
2) If your fans only turn on and of in high speed and typically stay on only for 20 seconds or so until extreme high temps are reached (110-120 degrees C) and you never see a slow speed fan condition. CHECK THIS FUSE
3) Most of the time the temp stays between 85-95 degrees C when operating at speeds of 30 MPH or more, but then in stop and go traffic - or low speed driving - temps can move up to over 100 degrees C and stay there until "something changes" (no clear indication of what made the temp go down). CHECK THIS FUSE