Mercedes-Benz Forum banner
1 - 5 of 5 Posts

· Registered
51 Posts
Discussion Starter · #1 ·
Hello all,
I have an issue with my m102 2.3 "fuel injection" spark plugs go black after some time specially after going on highways with high speed and the engine starts to run in a non-stable mode, as soon as I change the spark plugs everything goes to the normal state again. I faced the same issue from nearly 6000 KM and it happened again.
I think I have a good fuel consumption 11L \ 100 KM, my only note is that the car doesn't accelerate good in high speed and I have a low top speed of average 165 KM

Many thanks in advance

· Registered
Diesels om616 -> om606
526 Posts
what "temperature" are the plugs?
there are different kinds for different engines and driving styles, it might be that they arent geting hot enough.

that might be down to inproper "temperature" of the plugs, but soot buildup like you have might very well be that it is running to rich.
Low power is also something you can get when its running to rich, either from bad airfilter, or badly tuned.

When the engine is warm, and if you rev it, do you have a black cloud out of the exhaust/on the ground?

im in no way an expert on gassers, and this might very well be a completetly wrong suggestion, but thats where id start.
swap the airfilter, and see what temperature the plugs are rated for.

some like NGK goes from low to high, where a 5 is for a "normal" slow engine, and a 8 is something for a bike/sportscar where a 5 would overheat, and a 8 will be good, and vice-versa, a 8 would never get hot enough in a commuter car, and would be to cool.
others brands goes the oposite way, so its down to what plugs you are using.
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.