1995 w124 e300 rough idle.... - PeachParts Mercedes-Benz Forum

weisskasten · #1 10-26-2010, 02:06 PM

Hello to all!,
Newbie here. Not new to diesels, but the website.
Can anybody offer a lead here?
I have a very clean, spotless E300 diesel (OM606). I have no history of the car having just purchased it.
It starts up great in the morning and idles very smooth etc. However when it gets up to running temp, it violently shakes and idles like crap. It will slightly sputter up to 2000 rpms and then run fine all day(freeway)

thoughts?
No bubbles in lines, no leaks, etc.

thinking, filters/injectors

ps, theres a little oil in the bottom of #6 injector but its coming from the rubber breather? lines that go into the manifold.

Aquaticedge · #2 10-26-2010, 05:18 PM

Check the overflow lines between the injectors, Also replace the fuel filters, check your motor mounts, if they are worn they'd cause excessive shaking etc

Chris W. · #3 10-27-2010, 10:42 AM

New plastic fuel lines and O rings if you do not know when they were changed. If you are really on a budget you can probably get away with just the O rings.

New motor mounts if you do not know when they were changed.

New fuel filters would be good. If the car will pull to 4800 - 5000 RPM, however, your fuel filters are most likely OK. Running it through the gears up to these revs won't hurt it - I try to run mine up at least once a week to clean out the crud. I am running the original injectors, never serviced, so here is one data point that they will last a long time and work well.

Good luck and let us know if you make progress.

Rgds,
Chris W.
'95 E300D, 327K

vstech · #4 10-27-2010, 11:07 AM

click the buy parts link at the top of page, then choose fastlane, then put in your vehicle and look at fuel return lines. get a meter or two of the return hose, and change it. just cut to length of the hose on your lines, use needle nose pliers to pinch off from the side of the hose closest to the injector, and just push the new hose on. really simple.
that will stop the leak, but not fix the shakes. like has been said, air ingestion from the fuel filter o-rings are likely. swap them out and report back what changes.

weisskasten · #5 01-10-2012, 01:34 AM

So wow.....
I took so much of this engine apart.
-cleaned all manifolds
-checked flaps(operational)
-NEW wiring harness. Ouch
-took injectors in for checkup. "A ok"
-new fuel filters. One new o-ring.
-motor mounts ok

So plenty of awesome smooth power when cold. Warm/-shakes real real bad. Weak power. Kinda sputtery. Gotta be a sensor or something

benedict · #6 01-10-2012, 03:29 AM

[QUOTE=So plenty of awesome smooth power when cold. Warm/-shakes real real bad. Weak power. Kinda sputtery. Gotta be a sensor or something[/QUOTE]

I have the exact same problem at the moment and today was exceptionally bad. I have just replaced the engine/tranny mounts which did very little.I was thinking injectors but obviously not.

What temp does your guage say when you can feel the shake begin?

Mine begins when guage reads about 80C gets worse at 85C and cheek slapping at 90-95C.

connerm · #7 01-10-2012, 08:12 AM

I cleaned my tank strainer and performance increased big time. No more stumbling.

weisskasten · #8 01-10-2012, 03:17 PM

I noticed my 4 prong temp sender has no indexing for the connector to go on one way. You can put it on any which way. Have not checked tank screen.

weisskasten · #9 01-10-2012, 05:26 PM

Ok,
So I now noticed that there is no fuel shutoff on top of the fuel filter! Just a flat metal bolt. I didn't even know there was supposed to be one? Is this an update of sorts? It takes an oring and looks to be functioning.

weisskasten · #10 01-10-2012, 05:28 PM

In response.... I don't know exactly when it starts running crappy. Early on. It never gets too warm but yes above 85 it's bad

benedict · #11 01-10-2012, 06:54 PM

Quote:

Originally Posted by weisskasten

Ok,
So I now noticed that there is no fuel shutoff on top of the fuel filter! Just a flat metal bolt. I didn't even know there was supposed to be one? Is this an update of sorts? It takes an oring and looks to be functioning.

Your car (OM606.910) should have a shut-off on top of the main fuel filter, otherwise it makes it difficult to shut off engine should a vacuum problem arise.

These shut off valve's are pretty pricey for a 'bolt' so it has probably played up at some stage and the standard bolt from the later E300D's was used instead.

My shut off valve jammed up, thanks to a bright spark mechanic that used locktite on the thread, in an attempt to fix a leak. He fixed the leak ok but that was the end of the operational part of the valve. You can buy it from fastlane.

weisskasten · #12 01-10-2012, 07:15 PM

Thanks. I studied the two bolts one with shutoff And later one without. Oddly, the shutoff one has two o rings on it. The later one has only one. I wonder if this is a factor somehow. The fuel filter came with 2!!!

benedict · #13 01-10-2012, 07:49 PM

Best to change it or it will catch you out at a bad time.

First time I discovered mine was stuffed was when I was running late for a wedding at a church, jumped out and the engine was still running.

All I can remember was the sound of dak, dak, dak through the windows or the church for the entire wedding

At least my engine was warmed up and ready to go.

z3ds · #14 04-12-2012, 12:22 PM

Quote:

Originally Posted by weisskasten

Thanks. I studied the two bolts one with shutoff And later one without. Oddly, the shutoff one has two o rings on it. The later one has only one. I wonder if this is a factor somehow. The fuel filter came with 2!!!

Were you able to fix your problem?

weisskasten · #15 04-12-2012, 12:33 PM

Hi
Yes problem solved. There was a hairline crack in one delivery valve housing. I discovered it when I pulled them out to check. Upon retorqueing, it cracked in half. Apparently when it warmed up the crack would worsen? Anyway, a new valve has been installed. I had to then change the motor mounts(shot), and the belt tensioner(also ruined from bad motor mounts) Now it is so quiet and smooth. Wow!!!!