Just about a year ago I aqquired a 1979 300 CD and over the past year there has been a noticable reduction in power and acceleration on the highway and local hills around my area (cruising the city streets is fine, no problems there). It was at its worst during the winter months (maxing out at around 55-60 mph) compared to the previous summer when reaching speeds of up to 75 was relatively a breeze. My friends and I have been trying to figure out what the problem is and we only productive action we could take was replacing the air filter. All other ideas either lead to know where or are unpractical.
I only know so much about these wonderful cars and could use all the help i could get

Does any one have any ideas on what I could do to get her back up to speed?

Thanks

Your friendly neighborhood Diesel Owner

 

My first reaction (and hopefully those wiser than myself will chime in) is to run some diesel purge - there are several brands out there, but I like the stuff I get from Mercedessource.com - plus it comes with a good set of instructions - it's not something you pour in your tank, rather you disconnect fuel lines and run it through your system. You did not indicate how many miles on the car, but this stuff works wonders on tired old diesels (I've used it in both my old 300D and current 240D).

Not sure how mechanically inclined you are, but a valve adjustment may also be in order. I consider my skills Advanced Shade Tree, so I find it to be a pretty easy job. Again, same place has special wrenches and a good set of instructions.

Good luck, and keep us posted.

-Robert

 

Oh, and of course, fuel filters would be a good idea as well.

 

I have recieved advice to replace the fuel filter many times, but am pretty surefuel filters were replaced at the same time the water pump broke abouy 6 months ago. As for the miles, it is current at 191,000. I plan to look further into some diesel purge and maybe valve adjustment, but might be restricted on my mechanical abilities, we shall see.

thanks for the tips and keep it coming, ill keep you posted.