S350 TD eng. power issues
 

Hi there. New to the diesel forum. I just bought a 1996 S350 TD that was imported. It has 53k miles. Always I car I loved and have been searching for...

My question: on some days the car drives fantastically, fast, smooth, etc.. Others, it lags power and is very slow quite honestly! Always starts nicely, idles well and runs beautifully.. No oil consumption; no smoke..

We did store the car for a period and the battery was near dead when we pulled it out, although only 3 months old. I bought a high end charger and left it on there as we have left the car for 3 weeks once again..

Any thoughts?? Fuel? Fuel filter? Bad battery?? Bad turbo???

Thank you for any insight or suggestions..

All the issues you say you have are not suported by facts you just indicate "very slow"and therefore it is hard to offer sensible suggestions, except you can forget the battery.

Forgetting about us, I would start a log to include weather, outside temps/humidity and as many of the engine details for good times and bad times----do you start to see conditions or patterns that validate your "very slow" perception. Good Luck!!

Same issue...
 

I have a 1994 S350D that has sluggish acceleration about 10 minutes after it's started. It does the same thing every time it's started in any and all weather conditions. It accelerates normally after initial start up but just drops power by 30 to 40% after you get going. It's almost like the turbo stops engaging or at least has about the same lack of power affect. It seems like something gets switched off because nothing else is affected but the acceleration/power. Sounds like the same issue you are having.
I've had the fuel tank drained and flushed and all filters replaced, including the screen one in the tank and it had no affect. It doesn't smoke excessively when this happens and no check engine light is ever lit. It seems electrical because when it's shut off for a few minutes it takes off with full power for about the same length of time. I've owned several different Mercedes diesels and none have ever done anything like this before. Hope some of the experienced Mercedes folks here can help lead me in the right direction to finding a solution.

Hi, this sounds EXACTLY like the problem I'm having with my S 350 TD!
-I'm curious about if you've located the problem? It's a very annoying problem to deal with...
Please share the solution with me if you've got it fixed... :)

the turbo waste gate actuator is vacuum operated and problematic with its safeties that malfunction which in turn shut off boost
i had one some time ago and changed the actuator from vacuum to pressure and solved all future problems
search the forums for a solution, you should find a good writeup to fix this

or you could track down the actuator issue and stick with the factory vacuum setup

try this ----http://www.peachparts.com/shopforum/diesel-discussion/212097-wastegate-actuator-swap-om602-962-a.html