Okay the car is great condition with 106k mile. Oil and fuel filter changed religiously and I'm using Mobil 1 syn as well as 1/2 bottle of Redline on fill ups.

I took the car into the mechanic for vibration issues. The car at idle is shaking pretty bad. The mechanic recommended new motor mounts...which made the problem worse...

He went on to explain that this car had a problem with the IP. It viabrates, in my case badly. He said that MErcedes had a problem with this and in Europe tried replacing the IP.

Does anyone else have this problem? My 123 car doesn't vibrate at all or very little compared to the 124 car. I'm at the point were I'm considering going to the dealership to have them trouble shoot the issue.

Oh yes and I used two cans of diesel purge this weekend to see if it would help...nada...

My 93 does the same thing. I can see the hood shake at idle, if I put my head against the headrest, my "picture" shakes. just off idle it's smooth as can be. My 82 td is much smoother at idle, but never gets as smooth as the 124 at rpm. What did you ever find with yours?

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'93 300D 200k (since Aug 04)
'82 300TD 205k (since March 04)
'02 Ford Escape 192k (bought new)
'90 Ford Festiva 310k (since '92 with under 10k)
'01 Jeep TJ Wrangler 278k (since 07 with 235k)
'76 VW Westfalia van 150k ? (since '90 with 100k)
'72 Chevrolet Corvette conv. (base not a LT1) 175k (since '84 with 100k)
71' VW Squareback (since '72 with under 9k, odo turned over, then stopped then replaced. maybe 250k)
'87 Yamaha Riva 125 scooter 7k

You may just have a weak injector.

You'll need to isolate the problem. Try opening each injector line one by one and work out which cylinder gives the smallest rpm drop. With 100k mi your injectors are coming up for a service anyway but it's worth finding the sorce of your problem before throwing money at it.

A compression and leakdown text would be a valable check of engine conditon as well. I haven't heard of any common faults with the IP.

Have you checked you IP timing?

Do you have any other symtoms such as reduces fuel economy, smoke (mention rpm, load and engine/ambiant temp and color if you do), is it an even shake or uneven, in gear or out of gear (auto).

What is your idle rpm anyway?

__________________
Alex.

MB Tech
Sydney, Australia
Volvo 122S
W201 190D 2.5 manual
W202 C240
W203 C32

AusMBtech,
I just went out and checked my idle rpm. 600. I came home about 30 mins. ago so it was still close to 80c. At 1000 it is smooth, then coming down slooowly, it maintains untill 750-800, then shakes more as rpm falls back to 600. I don't have a book but guess that is to low. Never even thought about idle speed. To late to work on it tonight but I did check the throttle cable and there is some slack where it connects to the rod system. could it be as simple as that? What is involved with the injector service? Pull them and clean them? Add injector cleaner? Diesel purge? Does it make a difference if I open the injector line on one end or the other? Seems like the pump end would be easier. I'll make note of specificlly what the smoke does. My wife hates it, but casually I only notice it at heavy throttle = black smoke and at night in the mirror only a little with moderate throttle. I haven't checked the IP timing. Is that specific test equip. or just garage tools? Thanks, Mark

__________________
'93 300D 200k (since Aug 04)
'82 300TD 205k (since March 04)
'02 Ford Escape 192k (bought new)
'90 Ford Festiva 310k (since '92 with under 10k)
'01 Jeep TJ Wrangler 278k (since 07 with 235k)
'76 VW Westfalia van 150k ? (since '90 with 100k)
'72 Chevrolet Corvette conv. (base not a LT1) 175k (since '84 with 100k)
71' VW Squareback (since '72 with under 9k, odo turned over, then stopped then replaced. maybe 250k)
'87 Yamaha Riva 125 scooter 7k

Ok, sounds like getting the idle speed up is the first thing to be done.

I think the spec idle is 700-750rpm. I personally run my car at 850rpm (same engine, non turbo, no electric idle control).......I like the A/C working well at idle

I'm pretty sure that you have the electric idle control on your IP. There is a 2 pin electrical connector on the back of the IP. with the engine running disconnect it. The idle should drop. If it does then the idle control is working, if not then there will be some electrical diagnosis that I'll run you through in detail next week when I have the specs in front of me.

The base setting for the idle (with idle control disconnected) is about 600rpm, the idle control may be your fault.

Try that and get back to me

__________________
Alex.

MB Tech
Sydney, Australia
Volvo 122S
W201 190D 2.5 manual
W202 C240
W203 C32

I dove to Tenn. this weekend so it will probably be Mon. or Tues before I can test the idle control. I'll let you know then. Thanks

__________________
'93 300D 200k (since Aug 04)
'82 300TD 205k (since March 04)
'02 Ford Escape 192k (bought new)
'90 Ford Festiva 310k (since '92 with under 10k)
'01 Jeep TJ Wrangler 278k (since 07 with 235k)
'76 VW Westfalia van 150k ? (since '90 with 100k)
'72 Chevrolet Corvette conv. (base not a LT1) 175k (since '84 with 100k)
71' VW Squareback (since '72 with under 9k, odo turned over, then stopped then replaced. maybe 250k)
'87 Yamaha Riva 125 scooter 7k

How did you go with checking the idle?

normal idle should be 680rpm +-20rpm
Idle without the idle control solenoid connected should be 620rpm +-40rpm

I've got the list of tests in front of me now so I can run you through all the tests. I just need to know what it's idling at now.

__________________
Alex.

MB Tech
Sydney, Australia
Volvo 122S
W201 190D 2.5 manual
W202 C240
W203 C32

My saga continues, my car still has a bad vibration problem at idle. I just don't notice it anymore...

I'm starting to feel like an abused owner...I guess this would be my support group...

Anyway I think the problem is deffinately the injector pump, as anyone had this issue before?

i would be very surprised if it is the ip. it is more likely to be injector, or cylinder specific. did you do the loosen the injector line test yet? if you did and isolated the cylinder, if it is one, then a compresssion test is next.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I have the same problem - low idle speed and bad vibration. My motor mounts are shot and I was sure that was going to fix it but after reading this thread I have new doubts. A couple of things:

Were the motor mounts Mercedes OEM? I've heard rumblings about the aftermarket ones not being of sufficient quality.

When I disconnect the idle control, my idle drops below 500 and the engine nearly dies. Does this imply that the "base idle speed" (if there is one) is set too low? How does one adjust this?

Can someone describe the "loosen the injector line" procedure in a bit more detail? Does it simply mean loosening the nut where the line goes into the injector? Doesn't this cause diesel fuel to spray all over the place?

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-Dave

1. Check fuel delivery
2. Check compression

Yep the motor mounts came from mercedes... I figure the engine vibration is what killed them, basically my car eats motor mounts...

I going to check the car this weekend, if I can't solve it... it's off to the dealer. I have had good luck with Star, one of three dealerships here in Houston.

If the EDS idle control is not working the car will idle at around 550-600 RPM - and it will produce a notable vibration.

What does your tach read when the car is idling??????

I'll check...

Car is idling around 800-850 RPMs, and it's the same if its in neutral or drive.