The picture isn’t too great, but are you sure it really jumped forward?

The gear towards the rear of the engine looks like the gear that drive one camshaft from the other on the OM606

A timing chain guide likely broke, and the chain jumped the broken guide, remove the front timing cover to inspect the guides , if when you reset timing the engine runs ok, replace chain, tensioner and all the rails,

x2 The picture shows both sections of the chain on the driven sprocket. The visible sprocket drives the intake cam.

Something came loose and rode the chain to a weak spot in the valve cover.

Sixto
98 E320s sedan and wagon
02 C320 wagon

Despite the panic of others, replacing the timing chain and components isn't a big ordeal for those that have repaired engines. I'd rather fix a known good engine than get a high mile unknown used one that might suffer the same failure. This late in the game finding a low mile unit will be difficult and $$$.

Have a look at this pic:

http://www.w124performance.com/images/OM606_misc/605_valvetrain1.jpg



The chain runs the exhaust cam and a gear drives in intake cam. In your pic it looks like the front half of the exhaust cam chain sprocket broke for unknown reasons. Look at the front most row of chain. Starting from the passenger side there are 2 teeth visible but when moving towards the driver side the teeth are missing.

Given the engine still ran smoothly, valve bending didn't occur.

As for valve bending / not bending if a chain breaks / cams jump out of time, idle or freeway speed makes not one bit of difference. Valves can be bent by cranking the engine with the starter or even by hand.

The best case is when a chain breaks clean , the cam stops and one intake and one exhaust valve of different cylinders bends. There will always be some valves open at any given point in the cams rotation.

There are some dual cam engines that are called valve benders but can survive a belt breakage. Supposedly the Chrysler 2.4 used from 2000 to 2010 ish in the PT Cruiser , Stratus , Cirrus and mini vans is an example of maybe maybe not. If the cams stop with valves mostly closed, valve bending won't occur.

Worst case is when the chain hops a tooth or more and cam continues to turn. In this case all valves are opening at the wrong times and , depending on if single cam / dual cam + type of drive, either all exhausts or intakes will bend.

An example of this is the mid / late 80's 1st gen Buick 3800 V6. The engine can seemingly be running fine, get parked , shut off then won't restart. With these engines, the chain / sprocket wears to the point at shut down the chain hops over a tooth. Not knowing this has occurred, the driver cranks the engine and all of the intake valves bend. ( Might be exhaust, it has been a while since I fixed one of these engines. )

Thanks SL320 and sixto.... I have repaired engines in the past when I was a mechanic so I may take a shot at it.

There appears to be a timing cover just under the valve cover, not much information on line about the OM648 engine, as I believe this is.

I suspect that first I'll get the timing marks aligned to insure that it is 100% on time, then I'll go from there.

As stated, there are in fact teeth missing from the front of the cam gear, been looking on line for parts, most available are from foreign countries, I'd hate to pay full dealer price for a valve cover or any other simpler parts that need replacing.

My question at this point is that since it is apparent that the cam gear's teeth were damaged do I need to replace the timing chain as well?

Thanks guys!!!!

__________________
Currently Driving
2006 E320 CDI
1999 E300 Turbo Diesl
2002 ML500
1995 E320 Station Wagon


MBs I've owned
1997 E320 Assassinated by Pine Tree
1987 300E Wife Killed Engine
1981 300D Stretch Limo Total Loss
1970 250 Coupe 212,000 mi.
1974 450sel 184,000 mi.
1974 240D 377,000 mi.
1977 300D 204, 000 mi.
1979 280se God Only Knows!
1983 240D 130,000 mi.
1972 220D 280,000 mi.
1983 300SD 244,000 mi.

Yes, replace the chain as it has become stressed.

I'd also be looking into pulling the oil pan and removing broken parts. Does this engine have a separate steel lower pan?

Have a look on car-part.com this searches participating salvage yards, that might turn up a used valve / timing cover. If that does not work, look for self serve yards.

Always get pricing from the dealer network, parts that don't sell in volume through the aftermarket are frequently bought from the dealer parts network and priced much higher.

Look on youtube for legitstreetcars Alex's recent content is on his CDI. He got a manifold from a youtube viewer, so chances are that viewer has a parts engine. It may be a longshot, but may pan out in the end.

__________________

All Diesel Fleet
1985 R107 300SLD TURBODIESEL
2005 E320 CDI (daily)

LOTS of parts for sale!


EGR block kit
http://www.peachparts.com/shopforum/diesel-discussion/355250-sale-egr-delete-block-off-plate-kit.html

1985 CA emissions 617 owners- You Need This!
Sanden style A/C Compressor Mounting Kit for your 616/ 617 For Sale + Install Inst.

Sanden Instalation Guide (post 11):
http://www.peachparts.com/shopforum/diesel-discussion/367883-sanden-retrofit-installation-guide.html

How different is the timing system / valve cover from our guys engine vs a 1995 OM606 ?

IDI vs. DI


A lot.

__________________
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

Agreed. There aren’t too many full size cars that can get 45mpg

__________________
1993 e300
1995 e320
1994 e320
2006 s500 4matic
2004 Jeep wj overland
2001 Ducati 748
2004 Honda shadow aero

While I'm all for supporting this site, over on Rock (of) Auto, they have lots of engine parts on deep discount wholesale clearance. Valve cover gaskets are $ 4 , timing chain $ 66 , guides $ 5 to 6 , tension adjuster $ 57 , oil pump chain $ 17 , intake gasket $ 8 .

I've also found that there is a early 2005 and late 2005 + so be sure to ID your engine not just the car in case parts were changed along the way.

I agree with Sixto, especially if the chain rails and tensioner are OK.


Can you post a photo of the missing teeth? I'm not seeing that in your previous photo.


The chain doesn't automatically require replacement, but it would be a good ideal to mark a link on the chain, and turn the engine by hand so you can inspect the entire length of the chain. If timing marks are aligned, AND stretch is within factory specs, AND there is no visible sign of damage to the chain... I'd leave it alone.

You really should drop the oil pan and inspect for debris in the sump. This may also help solve the mystery as to what caused the valve cover to pop in the first place. It may be a miserable job; I'm not sure what's involved.

Replacing the valve cover won't be cheap either, new is ~$250 from discount dealers, a used cover may be difficult to locate. If you don't identify the root cause, you'll be really unhappy if you install a new valve cover and have the replacement cover suddenly get extra ventilation like the first.

With 200 K miles and the work involved / cost of parts, there is no way I'd put these timing components back into a customers engine.. . or my own. ( And I've put some really patched up engines together for cars for limited use / have limited remaining life. )

My CDI has been sitting since February. I was so disgusted that this happened that I pretty much gave up upon it.

So, it never jumped time and I have verified that by lining up the timing marks.

It looks like one of the chain rails let loose and rode the chain up until it was so tight that it broke the valve cover, teeth are also missing from the cam gear so that will have to be replaced as well. Disappointing that a Mercedes Diesel would do this.

So, I have worked on engines before, I was actually a mechanic at one point on my life. Guess what I'm asking is just how difficult a job this is and if specialized tools are required?

I have a price from a Mercedes Indy who says he can repair it for about 3K.

I am still undecided as to whether to fix it or not, the rest of the car is flawless. it was impeccably maintained and I have the service records to prove it... One owner!

My question is should I repair it or take the 3k repair cost and try to find another E320 CDI.

Thanks guys, any replies or opinions would be grateful appreciated as I am undecided as to how to proceed!

Thank you,

__________________
Currently Driving
2006 E320 CDI
1999 E300 Turbo Diesl
2002 ML500
1995 E320 Station Wagon


MBs I've owned
1997 E320 Assassinated by Pine Tree
1987 300E Wife Killed Engine
1981 300D Stretch Limo Total Loss
1970 250 Coupe 212,000 mi.
1974 450sel 184,000 mi.
1974 240D 377,000 mi.
1977 300D 204, 000 mi.
1979 280se God Only Knows!
1983 240D 130,000 mi.
1972 220D 280,000 mi.
1983 300SD 244,000 mi.

How is this going to cost $ 3K if you fix it yourself?