161k Do I need to change my Timing Chain?, damaged Injection Pump Timing device - PeachParts Mercedes-Benz Forum

777funk · #1 09-17-2007, 10:28 AM

I have 161k on my 300d (603 diesel engine). It runs great. It sat for about 2 or 3 years before I bought it. I got it running again with no problems. Anyways, I've already invested a good amount of cash and time into this puppy. Glad I have it's a great car. Very nice acceleration.

Anyways, before I go on my way with this car, I want to make sure it's not going to blow up on me. It's got the 14 head. Oh well, not going to spend that kind of cash and time at this point. But a new Timing Chain is around $110.

Do I need to do the chain job? Also, I've read when I've searched that it's good to also change the tensioner. ANYTHING ELSE???

vstech · #2 09-17-2007, 10:40 AM

it's doubtfull you need a chain, but be sure and check the vacuum pump. if it is the open bearing type, it could fail and destroy your motor.

777funk · #3 09-17-2007, 10:49 AM

This is one thing that's always kindof surprised me about 603 owners... the 617 drivers have only the open bearing type available and don't really worry about it.

I will of course change it. But when I drove a 617 engine people always seemed to say, 'change it when you hear it knocking'. Isn't there some type of similar warning with the 603's old style vac pump?

Biodiesel300TD · #4 09-17-2007, 10:56 AM

Have you inspected your chain and checked stretch? That will tell you if you need a new chain.

vstech · #5 09-17-2007, 10:57 AM

nope, no warning, just popped bearings and a destroyed oil pump, or worse.
the 617's have no openings to dump parts into the chain. plus it's a different style vp altogether.

C Sean Watts · #6 09-17-2007, 10:57 AM

I did mine a month or so ago. You will need a dial gauge and a fairly good base for it. Have fun and FWIW, I did mine and thought 15 DEGREES!!! Oh, I see, not from zero... I did it three more times just to be sure, I have ONE MORE DEGREE to go, whoo hooo!

777funk · #7 09-17-2007, 11:58 AM

Can you just measure stretch from the Crank and Cam timing marks? At least approximately?

I would think if the chain had stretched some (and of course no woodruf keys are in place), the cam tower marks would be off when the crank is at Top Dead Center.

777funk · #8 09-17-2007, 12:08 PM

So far this is what I will change (chain related):
Chain (of course)
Tensioner
Vac Pump

Anything else adviseable?

#9 09-17-2007, 12:09 PM

Quote:

Originally Posted by vstech

...the 617's have no openings to dump parts into the chain. plus it's a different style vp altogether.

You think? Check out what the vacuum pump did to my 617:

Stuck in NE - vacuum pump failed

Refer to post #24 for ugly photo, the whole mess ended up costing about $2500.

vstech · #10 09-17-2007, 12:50 PM

oh yeah, I remember your post! but a 617 this problem is WAAAAAY more rare than on a 603. a 603 has that set of bearings just sitting out there and just a little wear and they go all over the motor destroying stuff left and right!

Stevo · #11 09-17-2007, 02:35 PM

A friend of mine that is on this list found ball bearings in his "early" 616 oil pump screen,

indicating a past catastrophe caused by his diaphragm type VP.

#12 09-17-2007, 02:39 PM

Quote:

Originally Posted by vstech

oh yeah, I remember your post! but a 617 this problem is WAAAAAY more rare than on a 603. a 603 has that set of bearings just sitting out there and just a little wear and they go all over the motor destroying stuff left and right!

I agree that it is much more likely on a 603, and the consequences are likely to be much worse. I just didn't want to give the 61x owners the impression that it's OK to ignore a failing vacuum pump.

barry123400 · #13 09-17-2007, 06:56 PM

There are many reasons not to just change the timing chain without checking it. The most important is what if the previous owner changed it say 10k ago? Then just a waste of money.
More important is to inspect the chain guide in my opinion. If the chain checks good. There is no really sensible option to getting a proper chain stretch reading. To be accurate you have to make sure that an offset key has not already been installed on the cam. They tell me harbour freight has a dial gauge and magnetic base for about twenty five dollars on sale. Useful for other things as well over the years.

C Sean Watts · #14 09-19-2007, 10:39 PM

Quote:

Originally Posted by 777funk

Can you just measure stretch from the Crank and Cam timing marks? At least approximately?

I would think if the chain had stretched some (and of course no woodruf keys are in place), the cam tower marks would be off when the crank is at Top Dead Center.

You can check the cam timing that way, but that only really tells you that you have or have not skipped a tooth. The ZIP file is the FSM specified method and much more precise than eyeballing since it goes on valve lift to 'X'mm. For the 603 you're looking for the cam mark "7" (there is a table for that.) When you rotate to the point of 2mm of valve lift, a NEW chain would indicate 12 degrees AFTER TDC on the damper. The allowable wear on a 60X is "...if a difference of more than 4 degrees of crank rotation angle exists, replace the timing chain." There is no woodruff key for the 603.

Hatterasguy · #15 09-19-2007, 11:24 PM

Check the stretch. But on a 160k mile 603 their is probably very little. Put another 100k miles on it then start thinking about changin the chain.

I'd worry more about the vacuum pump, is it the old style?