i would think it will be the same as the 603.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Correct I just checked this as well.

If the timing chain breaks on a 603/617 you will probably bend a few valves and maybe crack a piston. So yeah its rebuild time.

But the timing chians are so overbuilt I just cannot see one failing unless it has some real high mileage on it, like 350k+.

Now the oild pump chain on the 617 is another story, at 300k it is probably worth changing that if you are a diy'er and plan on still keeping the car.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

timing chain failure diaster depends on the type of engine.
The main diaster is that a piston slaps into a valve and bends
the valve....

i have a ford truck that has a timing belt and it brakes ever 70k miles...
I just pull over and put a new one on.... the reason there is no damage is that there is clearance room at the top of the piston so its not possible to bend the valve... so no big deal...

i broke a timing chain on a dodge intrepid and it ruined the engine..
bent the valves...it was a 2002 and i did this in 2004...bad deal..

I have 3 mercedes and i have replaced a chain but yet to see one brake..
but it would depend on how close the pistons at tdc come to the valves...

Oh don't worry on a MB the engines you will blow it apart if the chain breaks. The models that usualy bust the chains are the older V8's. The plastic guides get brittle and snap, really the chian doesn't fail the guides do.

But usually when they do snap, the valves will knock the piston with such force that the cam breaks and very often the valve becomes part of the piston. Usually happens on start up. I have seen pics of failures at higher rpm's, the results are quite amazing...very often a large chunk of the valve cover is blown off...

Sleep easy diesel owners, I cannot recall hearing of a timing chain just failing on a diesel. They are all inline engines with nice short chains. I have heard of more oil pump chains failing on the 617/602's actually.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

It's possible. I've seen 3 in cars from a long ago job at a used car lot. They were a '72 240D, '83 300D, and an '84 300SD. In all cases the chain itself broke. The 240D broke the cam and cracked the #2 piston. The 300SD bent some valves and cracked the cam towers. The 300D was very lucky, no damage other than the chain.

I feel the chain and rails should be a scheduled preventive maintenance item to be changed at 8* stretch (At the camshaft) or 250K miles. It's around $250 for parts for $250K miles. Compare that to a possible $800-2500+ in repairs or a rebuild.

Yeah but I am assuming at a same age and mileage. If a 20 year old chain at 300k+ miles snaps, well its old what do you expect? The guides are plastic they are not going to last forever.

Anyone seriosly thinking about keeping their car for a very long time would be well advised to pull the front cover off and replace the timing chain, oil pump chain, and most of the guides before 300k miles.

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

your SD has the same engine as the 300D