All OM606 normally aspirated engines have "flaps" in the crossover pipe and intake manifold to "tune" the pipes for efficient breathing. In addition, the 1997 model (USA version, possibly world-wide) adds an electric switch to each flap; the switch talks to the system electronics and sets a code if the flap doesn't open when required. The following picture from the 1997 "Introduction into service" manual shows the flaps (99/4 and 99/4) and the switches (S35/1 and S35).



The switches are also shown in the 1997 ETM (Electrical Testing Manual) but I cannot find them in EPC nor can I get a part number for them. The flaps themselves are the same for 1996 and 1997 models -- the part numbers are identical (606-140-04-31 and 606-140-05-31). I think the switches are separate parts and there's no sign in EPC of an update for the flap in the 1997 model year.

What I'd like is for some kind 1997 E300D owner to go look at his/her engine and see if there really are switches attached to the flaps. You shouldn't have to take anything apart but a small mirror might help look underneath. If you happen to know where the switches are in EPC, so much the better.

Thanks -- Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

The switches are "micro type" switches integrated into S35 & S35/1 as shown on your attached diagram and they come attached to the vacuum flap assembly. I don't believe you can purchase them separately in that they do not have separate part numbers .... the switches come already installed/adjusted with the vacuum flap assembly .... I have a '97 E300D and have had to purchase a replacement flap unit in the past.

I was afraid of that . . . the flap prices went up January 1 along with most MB parts prices and are now in excess of $300 each, alas.

Interesting that the MB part number is the same for both 1996 and 1997. I wonder if a new flap bought today would come with the switch and would simply not be used in a 1996.

Thanks for your input.

Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Did you happen to photograph either the new or the old flap? Still have the old one or did it get tossed?

Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Does this ring a bell - http://www.peachparts.com/shopforum/diesel-discussion/258494-97-e300d-crossover-manifold-flaps.html ?

Are the flaps unique to 96-97 or are they used in the turbo engines as well? Maybe someone with a turbo engine waiting for a transplant can take pictures for you.

Sixto
87 300D

Sixto, that's it! I forgot all about that thread from only 4-1/2 years ago. Duh!

The turbo 606 doesn't have the flaps. There's a small possibility that some of the M103 or M104 gasser engines might have had something like that but maybe I'm thinking of the "throttle" flap in front of the EGR valve.

This pretty much confirms that the switch was included as part of the flap when the 1997 version of the E300 came out.

Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970