Timing chain?

Will a 603 even 'turn over' if the timing chain is broken, or will a piston soon fetch up against a valve and lock the whole engine?

JimH,

If the timing chain breaks or jumps only one tooth, one of the pistons will push against a valve and stop the engine from rotating. If enough force is applied, such as cranking the engine with the starter, the piston will cause the cam towers to break, and possibly bend a valve. If this happens when engine is running, more may be damaged.

Possibly after a while, the hydraulic valve lifter may leak down and then the engine will turn again.

P E H

That is really nice to get all the advice - ill look into the Vacume pump and if the crank is turning - its just been too cold- single digits- to work on the car.
Worst case

I have a cracked head, blown chain (not belt??), a loose (worn) engine, Bad piston and is the engine interference??

-It does crank but sounds 1/2 on off.

Is there somewhere to buy new vac pumps? I have searched through alot of MB parts sites but can only find rebuild kits. Is rebuilding them enough of a preventative.

Afaik their are no rebuild kits for the 603's vac pump, you can rebuild the 617's pump but that is a different animal.


Any MB parts site worth its salt should have a 603 pump listed Fastlane, Rusty, Adsitco ect.

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

The engine is definitely interference. In fact, I might take a stab and say that all M/B diesels are interference because of the very low chamber volumes.

Just in case anyone was wondering, I checked, and do indeed have the newer pump on my car. Figured I would, but nice to verify it.

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

i have a new vacuum pump on my car since its a nice new metal unlike the rest of the oily 20 year old grime coated block.. how do i tell its the good pump not the bad one

You don't have to worry. The problem was with the 603 engines.