My 1992 400E passed its recent CA smog test easily,
except for the EGR functional test, which passed, but just
barely. The tech applied vacuum to the EGR valve when
the engine was idling. Normally the engine should stumble/die,
but has to be passed if the idle decreases at all. Fortunately,
the idle speed decreased a little. . The tech mentioned that
the EGR would probably have to be "cleaned out" to pass smog
next time.

I've checked and cleaned the EGR valve, it operates
freely. But the idle speed still only decreases a little when
vacuum is applied to the EGR valve.

Is there a good/recommended way to clean out the EGR
passages on an M119? And what about the deposits that
are removed, is there any need to be concerned about where
they end up?

Thanks,
Forrest

Do a search on cleaning egr line. You use an old piece of speedometer cable and "roto-rooter" the line out from the egr valve to the intake manifold. I do not get too concerned with the stuff that gets rooted out going into the intake.
Make sure that the piece of speedo cable bends easily at the very end to insure it gets around any sharp bends in the line. I have had to do it on my E320. It will make the check engine light come on and give you a "faulty" egr code if it gets completely plugged.

__________________
Jim

Your search should locate a post, or series of posts by Steve Brotherton (I think) describing this procedure. Even haas some pictures of before and after. Should be very helpful.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

Jim and Mike,

Thanks for the replies. I've seen Steve Brotherton's article that describes the
procedure he performed on a CLK(?). That
engine has an external EGR line so there
would be less concern about stuff getting
into the intake. The EGR passages on the
M119 are incorporated into the head so
you can't see where the crud is going,
which makes me nervous.

Forrest
1992 400E (191k)

I too have an M119 (1994 E420) I keep getting a facult code 5 which is of course the ERG valve. where is the egr valve and where is the entrance to the line that needs to be roto-rooted?

The EGR valve is located at the left (passenger) front
of the engine. I think you'll need to remove the plastic
"cowling" piece in that area to access the valve.

The passage is under the valve and integrated into the
head. You have to remove the EGR valve, two bolts I
think, to access the passage.

HTH,
Forrest

ON the M119 engines, EGR flow malfunction requires removal of the intake..

The flexible tube between the upper section & plenum is always the problem.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

on man, sounds like more work than it was to change the oiler tubes. I don’t know what the area looks like, could you tell me a little more about this hose. is it a small vac line, or some other large rubber hose? Removing the entire intake means opening up the fuel system correct? Seems like I can’t just remove the EGR valve and poke around eh?

I'm gonna go search the forum to see if there is a thread that talks about removing the intake. does that mean I need to remove the MAF and throttle body (I kinda forget if the throttle is connected there or not)?

BTW I see you've in snellville. I live like a min away from ronald regan.

So what happens if the EGR were to stop functioning entirely on an M119? Power loss? MPG loss? I assume there will be a CEL, but is that it?

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

Does a faulty EGR valve or clogged tube cause the engine to have a bad idle where the engine sometimes will almost die when the throttle is depressed?

__________________
1992 Mercedes-Benz 400E
2002 Mercedes-Benz ML500

My trusty 400E failed smog due to EGR functional test; engine needs to stumble/die when EGR is activated (they've gotten stricter), RPM only decreased a little.

M.B.Doc, does intake manifold have to be removed???

What does "upper section" refer to?

Thanks,
- Forrest

Forrest,

Is that an updated sig in your 2001 posts, or did that car have 191k 9 years ago? How many miles now?

__________________
former: 83 300D, 97 C230, 93 400E

current: 08 C300 Luxury , 92 500SL

Will_w202,

Yes it's the same one, car now has about 216k . I've been commuting by bicycle for almost 8 years.

- Forrest

1992 400E 216k

Doc said the upper intake manifold needs to be removed. The M119 intake is a 2-piece manifold with an upper and lower portion. See image below. Item #14 is the upper manifold, #5 is the lower manifold.

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

Dave,

Thanks for the info. Looks like a 'bit of work' to clean out the EGR passage(s).

Do you know which item is the flexible tube that M.B.Doc referred to?

- Forrest
1992 400E 216k