Has anyone ever had a situation where the delivery valves were NOT leaking externally, but replacing the crush washer & o-rings resolved a nailing condition at idle? (Or has anyone ever encountered a broken delivery valve spring? (Assuming correctly or not that a broken or out-of-spec DV spring could possibly be causing nailing at idle?)

Reason for asking: My '98 E300 (OM606.92) has been nailing at idle on one cylinder. It's especially bad when cold, and it actually misfires under cold-start conditions. (The glow plugs all ohm out OK - but even if a glow plug was faulty, that wouldn't cause it to nail at idle while the engine is hot.)

I've pulled the factory original injectors out (to have Greazzer go through them) and I temporarily replaced them with a spare (used) set for the time being, but the nailing persists. Granted, I don't know the condition of the spare injectors, but the nailing is consistent – therefore my suspicion about the delivery valve.

It is definitely not a tank of bad fuel, as it has persisted through several tanks. (I also run Power Service at relatively high doses with every fill up.)

Any thoughts, opinions, conspiracy theories, etc. are much appreciated. Oh, and Merry Christmas too!!!

__________________
Current rolling stock:
2001 E55 183,000+ Newest member of the fleet.
2002 E320 83,000 - The "cream-puff"!
1992 500E 217,000+
1995 E300D 412,000+
1998 E300D 155,000+
2001 E320 227,000+
2001 E320 Wagon, 177,000+

Prior MBZ’s:
1952 220 Cab A
1966 300SE
1971 280SE
1973 350SLC (euro)
1980 450SLC
1980 450SLC (#2)
1978 450SLC 5.0
1984 300D ~243,000 & fondly remembered
1993 500E - sorely missed.
1975 VW Scirocco w/ slightly de-tuned Super-Vee engine - Sold after 30+ years.

Curious to find this out as well. My 603 seems to have the same symptoms, yet no external leaking. I've also swapped injectors and it didn't seem to change anything.

__________________
'98 E300 Turbo "Juliette"
'85 Federal 300TD

https://www.youtube.com/watch?v=-SW1dRGpHPU

__________________
'84 300SD sold
124.128

OM606 engine (W210 E300D/TD) delivery valve seals

__________________
'84 300SD sold
124.128

It can't hurt to replace the delivery valve seals, but this isn't a likely cause. I had a problem like this on my 190DT (602). Turned out to be damaged valve seats, which required sending the head to a machine shop.

Never at idle but at highway speed my car has had a nailing problem that I solved by re-torquing the DV holders. Also, tiny bubbles in the fuel lines can do it.

I also replaced the rubber line from the firewall to the fuel heater and that helped. I think it was sucking air somewhere along the line. Sometimes I get tired of chasing air leaks in that system.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

I just had my head done at a reputable shop so I doubt the seats are my issue. I suppose it's possible but so is anything

__________________
'98 E300 Turbo "Juliette"
'85 Federal 300TD

I like how the master cleaned the top of the IP BEFORE he removed the dv's POD's ip is scary dirty...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Thanks for the links Compress Ignite. And Vstech, I agree whole-heartedly!

KarTek: There are no signs of air in the fuel lines, even at higher revs - so that is not an issue. But the fact that re-torquing your DV's helped... that's encouraging!

MxFrank: Making sure that there are no mechanical deficiencies in the engine itself is something I will do when I've got everything apart - however considering the low mileage and easy life this car has had (90%+ highway use) I feel that it's very unlikely that there is a compression problem due to either a valve, ring, or head gasket issue.

As I typically do on any of my new (old) cars, when I "open up" an area, I just go nuts and replace every 'consumable' item so that I don't have to worry about it again for a long, long, Long time. When I have the manifold off I'll be replacing all the fuel lines, the DV seals, the SOV o-ring, and glow plugs. (If I've forgotten anything, please let me know guys!) I've already ordered Viton o-rings for everything even though I run only conventional pump fuel; I figure why not put the better material in. By the way, in addition to McMaster-Carr, believe it or not Amazon has viton o-rings available too.

I guess that I'm really looking for anyone's experience where there is verification / confirmation that the DV's can leak internally in some manner (past the crush washers?) and fixing that can resolve the nailing.

__________________
Current rolling stock:
2001 E55 183,000+ Newest member of the fleet.
2002 E320 83,000 - The "cream-puff"!
1992 500E 217,000+
1995 E300D 412,000+
1998 E300D 155,000+
2001 E320 227,000+
2001 E320 Wagon, 177,000+

Prior MBZ’s:
1952 220 Cab A
1966 300SE
1971 280SE
1973 350SLC (euro)
1980 450SLC
1980 450SLC (#2)
1978 450SLC 5.0
1984 300D ~243,000 & fondly remembered
1993 500E - sorely missed.
1975 VW Scirocco w/ slightly de-tuned Super-Vee engine - Sold after 30+ years.

When my 96E300 d delivery valves started leaking externally, I decide to repair them. Prior to me doing the repair, the engine ran smooth as silk at idle. The first time I did the repair, I did not change out the copper crush washers. A number of posters indicated it was not necessary to do so. The leak was fixed, but when I started the engine, it was nailing, which it had never done before. After driving the car for about 100 miles, the nailing was still there, and I decided to do the delivery valves again, only this time changing out the crush washers. Long story short, the idle was back to normal and smooth as silk.

__________________
96 E300d

Pimpernell,

Thank you! That is a VERY encouraging story, as it seems to verify that the crush washers themselves could cause nailing if they aren't sealing completely.

If your crush washers weren't sealing after you first replaced your o-rings AND that high-pressure leakage didn't blow out the new o-rings, then it logically follows that any crush washer leakage has an alternate path back out of the pump. Therefore (in theory) my pump's crush washer(s) may be leaking internally while still allowing the o-rings to remain intact and not cause external leakage. Good news indeed!

I sure wish that I had an old pump to dissect so that I could simply look at it to see how it functions - that would answer a lot of questions...

__________________
Current rolling stock:
2001 E55 183,000+ Newest member of the fleet.
2002 E320 83,000 - The "cream-puff"!
1992 500E 217,000+
1995 E300D 412,000+
1998 E300D 155,000+
2001 E320 227,000+
2001 E320 Wagon, 177,000+

Prior MBZ’s:
1952 220 Cab A
1966 300SE
1971 280SE
1973 350SLC (euro)
1980 450SLC
1980 450SLC (#2)
1978 450SLC 5.0
1984 300D ~243,000 & fondly remembered
1993 500E - sorely missed.
1975 VW Scirocco w/ slightly de-tuned Super-Vee engine - Sold after 30+ years.

I have one Cylinder that has 50 psi lower compression then the rest and it nails slightly when hot and more so when cold.

When I used to rebuild Fuel Injection Pumps in a Shop Delivery Valve Spring breakage was rare but I have seen it a few times.

What is going to be fun in this case is that if the Delivery Valve Seals are replaced people have said all of them nails for a few 100 miles.

Some People have claim issues with the Delivery Valves themselves that were solved by replacing them but I don't remember the specifics of the symptoms they were having.

__________________
84 300D, 82 Volvo 244Gl Diesel

Thanks Diesel911, your input is always appreciated - especially in light of your shop experience.

I've read about the post-seal replacement nailing issue, so I won't freak out unless it persists for several hundred miles. I guess we'll find out the answer once I receive the 33-point socket and all the other bits & pieces.

__________________
Current rolling stock:
2001 E55 183,000+ Newest member of the fleet.
2002 E320 83,000 - The "cream-puff"!
1992 500E 217,000+
1995 E300D 412,000+
1998 E300D 155,000+
2001 E320 227,000+
2001 E320 Wagon, 177,000+

Prior MBZ’s:
1952 220 Cab A
1966 300SE
1971 280SE
1973 350SLC (euro)
1980 450SLC
1980 450SLC (#2)
1978 450SLC 5.0
1984 300D ~243,000 & fondly remembered
1993 500E - sorely missed.
1975 VW Scirocco w/ slightly de-tuned Super-Vee engine - Sold after 30+ years.

D.M. only Torqued-Released-Re-torqued ONCE.

And the 605 idled perfectly.

(We've always been cautioned about the NEED to release and re-torque
Three (3) times .)

__________________
'84 300SD sold
124.128

Reviving this thread because the situation I have is just about identical to the one described in post #1, with the main difference being my car is not turbo-charged (1996 E300 with OM606, 184K miles). I've got a persistent nail at and a little above idle, and rebuilding the injectors made no difference. Searching led me to this and other threads about delivery valves being a possible culprit.

RunningTooHot - Did you ever resolve your idle nailing issue? I've got pretty much the same thing going on:

- One cylinder always nails below 1300/1400 or so RPM, worse when cold to the point the engine misses a little until warmed up.
- IP is dry - no leaks.
- Replaced all fuel system o-rings - no air.
- Replaced return and supply fuel hoses between engine and chassis.
- Replaced main and pre fuel filters.
- Pulled injectors and had all the nozzles replaced, and adjusted to pop within 5 bar or so of each other.
- One cylinder took a lot longer than the others to purge the air, and it made some nasty knocking noises in the process.

The engine runs better but the nail persists as if rebuilding the injectors did nothing for it. Under power the car is smooth and quiet. With no load the engine is quiet over 1300 - 1400 RPM but I do feel a subtle engine shake up to around 2500 RPM.

Here's a video I shot of mine and its nail. The engine was at operating temp after a drive. It's generally clattery around 1000 RPM and below, but there is one cylinder that nails consistently to about 1300 - 1400 RPM.

https://www.youtube.com/watch?v=vlmywW0wXmI&feature=youtu.be

Does my engine's nail sound consistent with what others have fixed by re-sealing the delivery valves?

__________________
- Greg -
1973 220D, The Prodigal Benz
1974 240D