Hello All I'm new to the forums as a registered user but not as a reader. I just bought this car 1995 E300D 240k registering and it needs help. Already replaced injector nozzles, pop tested, new heat shields, and all the plastic fuel lines and returns, runs great all but a dead miss in the # 3 cyl. with the intake off and running seems that one of the valves is stuck open it's as if there is blow back from one valve could this be a seat problem? I'm looking at pulling the head and do a inspection but looking for advice as to what it could be. and having to get some tools ordered also (pre chamber Removal wrenches) Anyone made them? or should i order them? Any and all advice would be greatly Appreciated

Barry

Do some searching for: e300 om606 valve seat recession

It does not appear to be mentioned much on this board, but UK members have written about it regularly. I think my valves are in the middle stages of this issue as well.

The UK owners mention that it seems most typical on the cylinders 5 and 6. So perhaps, you have a different issue.

I will suggest that you not jump to conclusions about this issue too soon. If you just did the injectors and are running the engine and noticing this problem, it is likely just carbon bits from the recent work which prevents the valves from seating.

After putting everything back together and driving for a bit, it is likely to clear up.

Also, the car may run just fine with this issue being pronounced only at idle. If you are getting good fuel mileage and the engine runs well, it really isnt an issue.

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If it does come down to valve issue, the prechambers will not need to come out unless the head needs to be skimmed (surfaced) - I guess this also depends on the particularities of the shop.

A competent shop should be able to deal with this issue and replace the seats and set them to the right height.

I wouldnt pull any prechambers to try to troubleshoot this issue, it is highly unlikely to help.

If you pull the head, be sure to replace the glowplugs while it is off.

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however, the prechamber needs a splined socket to remove the prechmaber retaining collar.

Then, a puller with a special attachment to hammer out the prechamber.

Some have made the puller / slide hammer - it is doable. The splined socket will need to be purchased.

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Thanks for all the info (1) the heat shield in #3 was not easy to get out but finally managed"Easyout and a lot of swearing"pulled glow plug and BLEW it out many times reinstalled new one and its very possible that there carbon built up under valve (2) have return line leak issues to correct ( not enough new hose used some old and it must be leaking) so when i undo everything to find that i was gonna remove head and check BUT if im not damaging anything i can live with miss for a while and drive it P.S. It's not my daily yet i want it to be

Dead miss as in engine shakes excessively at idle? A bit of carbon won't take out a cylinder like that. Is the blow back like cranking an engine without an injector? (A hard pop ) What is the history of this car?

Were the parts you changed an attempt to fix the miss? I'd also pull the valve cover and look at the valve train for a broken valve spring , exhaust valve not opening.

I think the next step is remove the valve cover to see what's going on with that cylinder's valves.

What is the history of the car, specifically recent repairs?

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

The first thing that came to my mind was maybe a broken valve spring which IIRC on this application you will have to pull the cam to inspect.

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Jim

I had the same problem on one of my '96 W210's.

At about 330k, the soot from the egr system had built up on the valve stems so bad that at least 1 would not close completely when the engine was cold. It would be hard to start from cold and would pop combustion gasses back into the intake manifold until it warmed up, then the valve would seal for the rest of the day. It sounded like a really bad rod knock.

I scrapped what I could off the valve stem.
With the intake manifold off and the engine running, I used a spray bottle of MMO on the valve stems. Over the coarse of 30 minutes I sprayed 2oz to 3oz of it down the intake ports with the engine speed from idle to 4000rpm. After that treatment the severity of the problem decreased significantly. I have driven it another 20k, but it really needs a valve job and the car is just not worth the trouble or expense.

When I first got the car, I tied the intake flapper open at the EGR valve, but I never installed a blocking plate from the exhaust manifold. If I had done that, the problem may not have happened.

The car consumes a lot of oil if it is driven hard / fast. I believe that the oil is leaving via the valve guide seals. There is no blow by out the oil filler cap.

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Greg
2012 S350 BlueTEC 4Matic
2007 ML 320 CDI
2007 Leisure Travel Serenity
2006 Sprinter 432k
2005 E320 CDI
1998 SLK230 (teal)
1998 SLK230 (silver)
1996 E300D 99k, 30k on WVO
Previous:
1983 240D, on WVO
1982 300D, on WVO
1983 300CD, on WVO
1986 300SDL 237k, 25k on WVO (Deerslayer)
1991 350SDL 249k, 56k on WVO - Retired to a car spa in Phoenix
1983 380 SEC w/603 diesel, 8k on WVO
1996 E300D 351k, 177k on WVO

the engine will use up its lube oil if its dropped a cylinder as the rings require pressure from the combustion to sit tight against the cylinder walls

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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)

two things will occur when an intake valve stem is carboned up.

The piston can hit the valve causing noise and making is close somewhat but not all the way.

There will be clearance between the valve stem tip / lifter / rocker / camshaft lobe.

Ok history of the car is unknown I have service records up the 200 k mark from dealer nothing after that . ? Is I am going back into it and look at the valve cup for complete stroke or movement of the valve I am going to try and find a scope to inspect the inside can the seat be seen with a brite light and is there a way to post video on this site. I have only replace/ rebuilt injectors and all fuel lines and filters and heat shields head removal is not out of the ? But would rather not What a source for parts for the 606 seems like they are very scarce in middle ga. Anyway. Thanks