OM606 NA breather plumbing question
 

While I have the intake off of the '96 E300D (W210, OM606 NA) to replace all of the fuel lines, return hoses, and o-rings with biodiesel-resistant materials, I'm looking at the breather plumbing, as it is leaking oil all over the valve cover, especially (see attached diagram from EPC) in the area of #30 (606 010 00 91 "differential pressure valve"). The "molded hose" #35 (606 016 04 81) feels like hard plastic and I suspect I'll have to break it to get it out of its hole in the valve cover. Hopefully I can do so without getting a lot of scraps inside!

Is this part #35 (and #38 and perhaps others) supposed to be rubbery and somewhat flexible? My parts are hard plastic -- age and heat maybe? but I have never seen new ones to compare. I don't see any o-rings in the EPC so I would think the parts would have to be somewhat rubbery in order to seal properly. There have been threads here before talking about the importance of replacing these parts with new ones but I have never seen anyone mention what the parts are like.

None of the parts are broken, just somewhat loose and leaking. I don't want to spend any more money than necessary.

Caveat: the diagram has been Photoshopped to remove bits and pieces that do not apply to my engine, so it will not look exactly like the picture in the EPC.

Jeremy

Yes. 35 and 38 should be soft and pliable. Basically, all of the connectors should be soft. I was extremely careful when I removed 35 because it was so brittle. Little pieces fell into the hole, but I was able to remove all of them with tweezers and bent nose pliers. None of the tubes were affected by heat or age, but I bought them new anyway. None of these parts have o-rings.

Thank you. Exactly what I needed to know.

I have found #35 for sale in FastLane and #56 and #59 from ********AZ and other on-line retailers but it would seem that the rest of the pieces must come from a dealer -- unless you or someone else has a lower-cost alternative.

PCV pieces
 

I've replaced three sets of those d*mn PCV hoses on three 95 E300s over the past few years, and on every one, the base of #35 broke off into the valve cover. Two times I was able to fish out the pieces, but on the last, I took off the valve cover to get the stupid pieces out. All were hard as rock, so do whatever it takes to keep the fragments of #35 out of that hole.

Good luck, Dave

Phil sells a complete set. Next time I'll only order the rubber connectors.

Maybe you should consider "testing" a straight hose after #30 to under the car and putting "test" plugs in the IM where this abomination connects to.
You worked too hard cleaning all that gooie tar from your car's IM. I'm right on the middle of cleaning this myself...

Actually, when I pulled the manifold this time, it was quite clean -- only a film of oil on the gasket from the breathers, no soot at all since the EGR valve 'broke.' I agree that the arrangement is overly complex and should have been routed out to the crossover as a single pipe rather than the rat's nest it is today.

I ended up buying 35 and 38 from my local dealer--don't remember whether I couldn't find them elsewhere or just didn't want to wait for shipping. Each one was a little under $10. Would be worth checking Phil's price for the complete set, but the hard plastic tubes can easily be reused if not broken.

56 and 59 were also brittle on mine and broke into pieces upon removal.

For 35, you might try cutting off the bulk of it, then holding a vacuum cleaner nozzle up to the last part as you try to pull it out with small pliers. The vacuum should prevent fragments from falling into the valve cover.

That's a good idea. It looks like #35 is partly broken anyway. I hope I can get all the pieces out without having to pull the valve cover as Dave had to do.

Finished!
 

Got the job done today. All the fuel line o-rings replaced w/viton, injector return jumpers ditto, cleaned up the top of the valve cover and installed all the new pieces of the oil vapor distribution plumbing system -- what a rat's nest compared to older, simpler engines like the 601-2-3 and the 61x family with their single tube breathers.

"Before"

http://i323.photobucket.com/albums/n...D/IMG_3250.jpg


"After"

http://i323.photobucket.com/albums/n...D/IMG_3258.jpg

This is one of the big advantages of DIY -- a hired mechanic would never do the cleanup and we would not want to pay for it if he did (at mechanic rates). With the new breather parts it should now stay clean.

What with having all of the fuel lines off the engine (and therefore full of air) it took a bit of cranking to get the engine started but it eventually caught and ran fine with no leaks -- yet. I'll keep an eye on it for a week before putting the middle belly pan back on.

It did manage to throw a couple of codes -- P0200 "injector circuit malfunction" and P0120 "throttle position sensor." The injector code was probably due to the long cranking time; I've never seen it before. The TPS code has been showing up occasionally and is probably related to the occasional problem I've seen with poor low speed throttle response -- I think the wiper inside is not making good contact (no, it's not the K40 module ;)). The TPS is just a potentiometer but it's very expensive ($500) so I hope it's something I can fix with a little contact cleaner as if it were a piece of stereo gear. I cleared both codes with my ScanGauge.

Jeremy

Looks great! I'll probably need to check this on my car. Where do all those #56 pieces go into? Must be a non-turbo thing - I think mine only has one line into the turbo inlet.

Here's why you can't trust EPC . . .
 

I've never seen the "top" off of a turbo ('98-'99) OM606 but I sure hope it's simpler than the mess they made on the NA version. Parents: this is what happens when you try to be "fair" to the family and divide things up evenly among 12 children (intake valves).

BTW, this is an excellent example of why you can't accept the drawing in EPC without checking. The actual plumbing in the engine is not quite what is drawn . . .

http://i323.photobucket.com/albums/n...D/As-drawn.jpg


http://i323.photobucket.com/albums/n.../Corrected.jpg


Thanks to Photoshop, this is what's actually in the OM606 NA engine. The parts list has the correct quantity of bits and pieces, fortunately, because that's what the dealer's parts guy and I went by.

Jeremy

What that picture also shows is how the rearmost inlet valves won't actually be getting their fair share of oil mist.

That, and perhaps the rearmost cylinders running hotter are the reasons why I think inlet valve seat recession tends to happen towards the back of these engines first.

Jeremy5848 - Thanks for posting pics! :) I'm following your thread with interest as I'm right in the middle of my clean-up project also.
I was trying to remove my #35 piece and it was so brittle that it also broke, I had the upper-outside part on my hand and the lower-inside-of-the-valve-cover piece is still in there in one piece. I'm going to take my time getting it out using the vacuum-cleaner method as suggested.
All of the plastic pieces that connect to the intake manifold (#56's) were also hard and brittle and they broke the nipple when I pulled them off. I don't think I'll be replacing them though...I'll probably go a different route. I'm thinking of plugging all these breather holes in the IM and venting the fumes under the car using the plumbing from the newer 606 turbo models- I worked too darn hard at cleaning my cross-pipe and IM to ever let any of this junk back into my baby's lungs again.:D

It looks like that drawing is for both turbo and non-turbo models. Parts 20, 65, 68, 71, 74 and 80 look like the ones on my car.