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MORE: Mercedes Benz 300se Repair Questions

Question: 1991 Mercedes Benz 300SE 3.0 I6 mileage: 113K. The car idles fairly smooth, but when put in gear the idle becomes quite rough. I have performed maintenance of all filters, plugs, and oil change. I have not changed the plug wires (they appear to be original) the plugs are not discolored and seem to be firing correctly when checked with a timing light. The wires are expensive so would prefer not to change them if not needed. The car runs well at speed but am afraid the roughness is being masked by the increased Rpms. This problem is not always present, but I have been unable to determine a pattern. We have been using 93-octane gas as recommended. We recently purchased this car so do not know the history of this problem. Steve

Answer: Do a compression check first. The plug wires can be checked by observing the running engine in very low light "night time" and watch for arcing. If they are arcing, replace them and your problem should be solved.

Question:  1985 Mercedes Benz 300 SE V-6 mileage: 79,000.  There was a question similar to this one.  I don't have problems starting the car, but twice now, it has stalled while driving.  It stalled when my foot was off the gas, while coasting.  I took it in last time for a tune-up, all they found were some corroded wire-but then it stalled again today.  The car has been pretty well maintained by the previous owner and me.  What could be the problem?

Answer:   Your stalling problem may be cause by the fuel pump.  Replacing it and the fuel filter should fix your problem.

Answer:   Your stalling problem may be cause by the fuel pump.  Replacing it and the fuel filter should fix your problem.

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