I've found a 95 N/A that I'm interested in, but have some reservations about this motor given the talk about the (#6?) inlet valve recession issue. I'm looking for one of those 400-600k experiences that we so often hear about on forums like these, and am prepared to commit the necessary care and maintenance to realize any such potential. As far as I can tell this is mostly limited to the OM617 and OM602 motors, but I'm hoping some knowledgeable soul can convince me otherwise with the OM606.

What is this valve recession issue? News to me.

Jeremy

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"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

Never heard of this either

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1987 300D 180k
1985 300SD 330k Helga
1992 300D Lola 269k- Sold
1986 325 coupe Bessie >300k Original engine(ODO Broke) sold
2006 2500HD Druamax Linda- Tows boat and looks pretty in garage thats about it

Looking at your signature, perhaps I shouldn't say. But, well, turns out some folks have noticed roughness at idle (among other symptoms) only to discover that their #6 inlet valve seat had sunken so far into the head that the hydraulic adjuster could no longer fill make room for the valve. Or something of that nature.

Worked on many om606 as a Mercedes technician never seen this

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1987 300D 180k
1985 300SD 330k Helga
1992 300D Lola 269k- Sold
1986 325 coupe Bessie >300k Original engine(ODO Broke) sold
2006 2500HD Druamax Linda- Tows boat and looks pretty in garage thats about it

How many were over 150k? Not sure, but I think that's about when people started to see this. One example of this experience:

http://www.peachparts.com/shopforum/diesel-discussion/209339-om-606-nailing-idle-6.html

Another--start about 4 posts down. I've seen this reported on many other sites too:

606 starts fast and perfect, smokes and misses till warm

I have a 96 OM606 NA with almost 262K miles. Never heard of it either.

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06 MB E320 CDI 123k miles
14 Sienna (wife's DD) 36k miles
11 GL350 Bluetec 136k (Sold)
96 E300; 292k+ miles (Donated)
11 Sprinter 22K+ miles (Sold)

Apparently there was a problem with valve recession on the early production OM606 motors. Since the US didn't get the E300D until 1995, then it probably isn't seen much for the most part of the forum.

MB started production of this motor somewhere about March of 1993, I think.

We have the early motors over here in Australia. Mine is dated 1993.

I'm not sure what they did to rectify, maybe a change in the somewhat over engineered breather system?

Also, My signature says mine is a 1995 but it is really a 1993. Someone here on the forum suggested I do this as I would get more responses to posts.

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1995 E300 Diesel

The majority of the posts I've found (here and elsewhere) come from U.S. model owners, 1995-1996--which is all I have to choose from if I want a N/A OM606. So I have to conclude that there is an unknown variable here, given the number of folks who've report an excess of 200k on theirs. I'd love to commit to this motor, but given that my project goal is to find one for a "life-long" vehicle (so far I'm in good health), I'm inclined to go with the somewhat more time-tested OM602.

Keeping your crankcase vent system in good shape should mitigate the damage. Also, it's not the end of the world to have a valve seal installed at a machine shop.

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-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

The crankcase breather system design is dependant on the suction effect in the intake manifold which is optimised by the resonance flaps - if those flaps are sticking or bad the last cylinders may have a little starvation of the blowby fumes.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

The crankcase breather system in the 606NA engine splits the vapor into 12 parts, one for each intake valve. If the small passages that feed the vapor into the head get clogged with soot from the EGR system, the valve stem lubrication will be reduced by a small amount. Would reduced lubrication due to a clogged breather then cause valve recession? I can't imagine that Mercedes designed the engine to depend on the breather system to provide valve stem lubrication.

In the case of my '96 E300, purchased at 249,000 miles and opened up by me to check the breather system, I found the plastic plumbing badly deteriorated and leaking and the intakes badly clogged with EGR soot. The worst was cylinder #6 (rearmost), where both breather holes were completely clogged. I cleaned the intake, replaced the breather plumbing, and blocked the EGR valve.





In my case, the head was not pulled so I can't comment on the condition of the valves. The engine had/has no idle problems before or after the work described above. The intake has stayed clean since the EGR system was blocked. The engine is now at 287,000 miles and has no starting or idling problems, cold or hot.

Jeremy

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"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

So interesting!

My silver one just turned over 313k miles and the gold one just turned over 269k miles without any valve issues. Both cars start, idle and run out great.

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Jim