HARD idle - PeachParts Mercedes-Benz Forum

clint77002 · #1 10-23-2006, 05:48 PM

This concerns my 124, 87 300D
The car developed a hard idle...shaking and dull rumble when starting first thing in the morning (temp between 40 and 60^F). After driving about 10 minutes, the dull rumble and shaking is much less but still noticably there. The IP was leaking alot and there were bubles around injectors 1 and 2 (looked like between the prechamber and head, not injector and prechamber).
I replaced the return lines and valve delivery seals (all were in need of it) and the leaking stopped. I still had the hard shaking. I pulled injector 1 and 2 and replaced the heat shields. Injector 1 had a good bit of carbon build up around the edge and the threads (head threads) were a bit carboned up. I cleaned the injector and head threads and retorqued both injectors (I replaced them one at a time to avoid mixing them up) to 71Nm. The bubling stopped on injector 2 but is still present (but MUCH less than before) on injector 1.
It all sounded like a rack damper problem but, after reading Gsxr's post, the 6cyl 124 does not have one.
I ran 2 cans of diesel purge and the smoking at idle stopped and after 10 minutes of runing on diesel purge, the motor sounded like a new beast...beautiful.
It started suddenly, so I don't figure its the motor mounts.
What else should I look for to stop this hard shaking?

Thanks,
Clint

92497pmu · #2 10-23-2006, 11:26 PM

Clint

I know we have different models, but does it sound/ feel like this?!?!
http://www.peachparts.com/shopforum/showthread.php?t=166261

I'm very curious if this is not just an e300 problem and maybe we can get some more minds to solve this.

Thanks

clint77002 · #3 10-24-2006, 10:08 AM

Phil,
Thanks for your post and directing me to your other posts. Our problems sound similar. My is most severe in the morning but the problem persists all day. I will look at the idler pully tonight, I hope. It feels like one cylinder is not getting fuel (similar to when I was looking for a nailing injector by loosening the injector line nut). Here is what I'll do tonight:
1. Loosen each injector line to see if there is a change in the shaking. If I find one that does not affect the shake, that's the line of interest.
2. Check idler pully and belts for wobble.
3. Retorque the delivery valves.
4. check for any fuel leaks

I'm baffled at the hard shaking and it started fairly suddenly but has grown worse. It happened before the delivery seals were replaced.

I hope to have some news (hopefully good/successful news) tomorrow morning.

Clint