Mercedes-Benz Forum banner

1 - 3 of 3 Posts

·
Outstanding Contributor
2006 ML500 2002 ML320
Joined
·
17,579 Posts
Hi

I have a late 2003 ML270 CDI. The car drives fine and accelerates strongly from standing.

I have noticed however that at 70 mph cruising on the motorway if I accelerate gently I get a pulsing or surging acceleration. The rev counter echoes this pulsing by moving up and down.

This is not a violent pulse and up to that speed the car drives perfectly. I have changed the air filter thinking that may be causing it, and although extremely dirty the problem has not been fixed.

All thought appreciated.
I rarely work on diesels but since you said that your air filter was very dirty, I would remove the Mass Air Flow insert and spray clean it with CRC Mass Air Flow Cleaner. Not knowing where you are from, I do not know its' availability, but try and get this product, it works very well. If not use an electronics spray cleaner.

Also, try hooking up a scanner to the truck and see if there are any codes stored.
 

·
Outstanding Contributor
2006 ML500 2002 ML320
Joined
·
17,579 Posts
Were you able to spray the very thin wire on the insert? That is the important one. Remove the two screws (see phot #7) pull out the insert and spray the wire clean. If after doing this the truck runs remarkably different (worse) then you need a new MAF.

Note: The screws holding the insert need a #25 Torx Plus w/security socket, but don't waste your time finding one. Either use a vise grip or cut a groove in each screw so you can use a flat screwdriver.
 

Attachments

1 - 3 of 3 Posts
Top