Trying to be proactive in maintenance.....have had several episodes in last few months of "engine...hesitating at part load with no fault codes." Car would not downshift and turbo seemed inoperative. All restored to normal after car shut off and restarted. Dealer said to wait till it starts to throw codes (if ever).

Any first hand experience on EGR clogging? The first 2005 CDIs had a different EGR valve that was replaced by MB along with software upgrade. I wonder how many of the first type of EGR valves caused/will cause problems? Wonder how many of the new EGR valves will cause problems?

How many of the 2005s had work done by MB (please check your VMIs and report back)?

Here is excerpt from DR. Diesel in 2006:
----------------
Quote:
Originally Posted by DR.DIESEL View Post
Hello,

Those EGR valves have been known to be trouble and were modified.

See the following Dealer technical Bulletin.

DTB Date: January 10, 2006
Order No.: P-B-07.16/55a
Supersedes: P-B-07.16/55 dated October 31, 2005
Group: 07
SUBJECT:
Model 211.026
Engine Performance Complaints / Check Engine Light On with Code 2511 and/or 2355
If you receive customer reports in the above model vehicles of the engine being in limp home mode with the check engine light illuminated with fault code 2511 and/or 2355 stored in the engine control unit (ECU) or
the engine is surging/hesitating/misfiring at part load with no fault codes, perform the below procedure to resolve. These may be caused by the EGR valve temporarily binding and consequently exceeding the setpoint and causing the fault code and limp mode condition; or the software version in the engine ECU (lean condition under certain RPM/load, temperature and fuel quality conditions).

To resolve, install modified EGR valve (see parts information) combined with ECU software update (available as patch 2005-10-13-0474 with DAS update 10/05 and later DAS updates without patch).
Note: It is important that the modified EGR valve is installed together with the modified engine ECU software and vise versa.

Note: After the software flash, perform SCN coding (refer to Star Tekinfo Document S-B-07.61/38g or S-B-07.00/144) and verify injector coding.

Parts Information
Qty. 1 EGR valve A646 140 19 60

I would ask your Dealer about some goodwill reimbursement or checking the Fedral 8/80 emmissions warranty for that model.
If no luck, call the CAC at 1-800-FOR-MERC and start squeaking.
The regional SPOM will be notified of your complaint and should respond.

Good luck.
DR.D
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Any shared experiences would be helpful to me and future members......

__________________
-- Chris

'95 E300, 216k miles, Silver Surfer
'05 E320 CDI, 138k miles
'07 S550 4matic, 69k miles

Gone but not forgotten:

'76 300D, 350k miles?, SOLD in 1995
'75 240D, 300k miles, SOLD in 1991