I have a 300 sdl and want to do a diesel purge to clean the injectors. It has not been done in at least 2 years. The question is do I install the new fuel filters before the purge or after? It seems to me if a install new filters before the prurge it will just gunk up the filters right away.
Thanks

It was my impression that you were supposed to arrange a closed system... with the diesel purge introduced into the rear of the injection pump... and the overflow from the injectors running back into a clear container... so that you could be running on ONLY DP until almost all of it was used up... the reason for the clear container is so you can see when you are about empty and can stop before you suck air into the injection pump....As small as the bottle of DP is I did not think it was supposed to be going through any filter... but someone who is for sure should post soon...

That's precisely how to do it. Get a pickle jar, cut two holes to match the return line and supply line, dip the hoses in and let 'er rip.

Takes 20 min and when you get close, use the under hood shut off, pour the rest left in the tank and rock on!

I don't have the diagram in front of me but I seem to remember that the instructions from Performance Products has Diesel Purge fed downstream of the prefilter and upstream of the IP's external pump. That means Diesel Purge will go through the preheater if the thermostat's open and through the main filter.

I wouldn't worry about running Diesel Purge through the main filter. It is, after all, a filter.

I run Diesel Purge when I replace filters so step one is to fill the new filter with Diesel Purge. The rest, not much, I put in a small jar per the Performance Products instructions.

Sixto
91 300SE
87 300SDL
83 300SD

I did the DPurge last night. FIrst did the purge(rev the engine by hand to blow Purge through the injectors), then changed the filters adding Purge to the filters before reinstalling. Then pumped the air out with the hand pump on the 300D. I must say, this Diesel Purge thing is amazing! My 300D rides so smooth and peppy now, even the auto transmission shifts smoothly. Incredible what $20 will do. I used 2 cans as this was my first time and I didn't want it to suck air.

I have been having mpg problems with my 350SD and have used a product by power service - diesel injector cleaner. I normally use redline diesel catalyst and have had great results. Unfortunately, I can not get redline in the KC area, where the car is. The car has been off the road and I did run the tank almost empty - it was dirty and old. I have replaced all fuel and air filters and the fuel is perfect with no sign of contamination.

Do you think I would gain benefit, i.e. idle, less smoke, better mpg from diesel purge that another product would not offer.

Also the say you can put diesel purge in the tank. Which is better from experience?

Thanks!!!!

I would think that Diesel Purge works best as a concentrated flush directly into the injectors. It's too expensive and diluted to waste it in the gas tank. Lubro Moly makes Diesel Hi Test for that.