Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

LinkBack Thread Tools Display Modes
Old 08-08-2006, 11:44 AM
Registered User
Join Date: Aug 2005
Posts: 81
240D - Runs VERY Rough at 1,000 RPM

I have a 1983 240D. I have noticed that at idle the car shakes more than it used to. If I touch the accelerator lightly and raise the idle to about 1,000 RPM, the shaking gets much worse and the engine misses and runs horribly. If I accelerate a little further, everything smooths out and the engine runs fine.

There is no noticable decrease in power and acceleration feels strong, (as strong as it gets in a 240D), and smooth. Fuel economy is about 28 to 29 MPG, which seems good.

I just took this car on a 1,900 mile road trip with my wife and did the "Italian Tune Up" multiple times while climbing the hills of Pennsylvania. This had no effect on the miss at 1,000 RPM. Still the same.

Also, worth noting is that the number 4 injector - near the firewall looks wet - like it might be leaking fuel where it screws into the block. Not sure if this could be effecting it. Figured I would mention it since I never saw that before. Also, the valves were just adjusted before going on this trip, so I know the clearances are within spec.

Any ideas? I really appreciate the help. Thanks!

Reply With Quote
Old 08-08-2006, 12:30 PM
rrgrassi's Avatar
mmmmmm Diesel...
Join Date: Jun 2006
Location: Royse City Tx
Posts: 4,872
Fix the fuel leak. That can cause rough running from fuel starving.

70's SPM #5608 Fairmont A-4 MOW car

06 VW Jetta TDI 210K miles

03 VW Golf TDI 5 speed 372K Miles

RIP--Lost in fire...82 300D 322K was My Daily Driver-On the search for a w126 now...

90 Dodge D250 5.9 Cummins/5 speed. 350K
Reply With Quote
Old 08-08-2006, 12:54 PM
Dale 240D
Join Date: Mar 2006
Location: Gainesville, Fl
Posts: 84
fix fuel leak

The fuel leak might just be the return lines deteriorating. They are generally cloth covered and run in a daisy chain configuration from one injector to the next and then to the fuel return line. It should still be fixed though. Clean up the area and see if you can tell if it's coming from the injector itself or where the return lines are. I just replaced these on my 83 240D. The return line hoses are cheap and easy to fix. They just push on. I overpaid for mine at 12 bucks for 18" at the dealership, i'm sure phil sells it here cheaper.
For the shake i'd check the engine mounts. If it only happens at one rpm spot, thast's got to be it. Also some people have commented that a broken air cleaner mount(yes!) can cause an awful rattle.

Dale 240D
Reply With Quote
Old 08-08-2006, 01:11 PM
Stevo's Avatar
Registered User
Join Date: Apr 2002
Location: NW WA
Posts: 6,296
I think I would try and find out which cylinder is the problem by running the engine at a "running rough' RPM, then cracking injector lines and see which one doesnt make a differance. Not so easy with the 4 cyl engs but you might be able to tell, then go from there, check pre chamber, injector, compression.....anyway try and find the problem cyl first. The fuel leak is most likly return hose, not a big deal.


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 12:16 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page