This morning the check engine light came on when first started. I drove it to a gas station to fill the tires to spec, and it seemed to be running in limp mode. Yesterday, on a run from Tucson to Las Vegas it went into limp mode 3 three times. I reset it each time by pulling over and restarting the engine.

The display showed Malfunction a couple of times, and showed check tire pressure a few times on that run.

I was planning on driving home to Idaho today, but since it was in Vegas, I drove it over to the MB dealer. It was sluggish on the freeway, not really wanting to go faster than 60 mph.

After 3 hours, the service rep said the servo motor in the intake was shorting out, due to oil leaking onto it. Without this servo working the flaps in the intake, the fuel/air mixture is incorrect and the check engine light comes on, and it goes into limp mode.

To replace the "swirl flapper motor" the intake manifolds are removed. They said they would also repair the oil leak.

I searched a bit and found only one similar problem. Apparently an oil line on the turbo can leak onto the servo motor, shorting it out.

Has anyone seen or repaired this problem before? Can anyone provide more details? The dealer is charging $3500 for the repair and its going to take 2 days.

So I'm stuck in Vegas waiting on the repair.

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1st MBz: 1982 300SD
2nd MBz: 1987 300SDL
3rd MBz: 1995 S420
4th MBz: 1987 190DT
5th MBz: 1984 300SD w/1983 300DT engine
6th MBz: 1999 C230k I'm 3rd owner, got it w/57,235 miles.
and manages Mom's 2007 R320 CDI

Sounds about right. The OM642 can be a real heartbreaker.

Thank you for the reply. This is mom's car and I have not worked on any MB this new. I've had 1982 SD, 1987 SDL and 1987 190D 2.5 Turbo.

__________________
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1st MBz: 1982 300SD
2nd MBz: 1987 300SDL
3rd MBz: 1995 S420
4th MBz: 1987 190DT
5th MBz: 1984 300SD w/1983 300DT engine
6th MBz: 1999 C230k I'm 3rd owner, got it w/57,235 miles.
and manages Mom's 2007 R320 CDI

The dealer also told us that the compressor for the rear suspension system is worn out and does not make compression. They wanted over $800 to repair it. Since that fault does not cause it to go into limp mode we decided to repair that after we got back home. The run from Las Vegas to Southern Idaho went well, 510 miles averaging 71 mph.

Where is that compressor located? Maybe I can swap it out.

__________________
.
1st MBz: 1982 300SD
2nd MBz: 1987 300SDL
3rd MBz: 1995 S420
4th MBz: 1987 190DT
5th MBz: 1984 300SD w/1983 300DT engine
6th MBz: 1999 C230k I'm 3rd owner, got it w/57,235 miles.
and manages Mom's 2007 R320 CDI

The compressor is located in the right front wheelhouse, just behind the bumper. Make sure you fix any leaks in the system before you replace the compressor. They usually fail due to excessive run-time. Pay close attention to the rear air springs.