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.

dieseldiehard · #5 09-20-2007, 12:17 AM

Quote:

Originally Posted by 777funk

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?

I know a 123 that was destroyed by a vac pump that disintegrated, they aren't immune from that problem but it was a run of the vac pumps on the 603's that were cost reduced or something and are responsible for a lot of dead engines

Don't wait until you hear knocking unless you like to tempt fate. They can fail before any noises start. Timing chain? If the engine runs strong you probably don't need one. I replaced mine at something like 260K just because the engine was being rebuilt. If your radiator isn't fairly new I would consider changing that as a plugged radiator can lead to a warped head. flushing one out is another alternative but they sometimes crack and leak.

#6 09-20-2007, 10:17 AM

Speaking of vacuum pumps, my "new" 617 vacuum pump just started making noise again (about 60K miles, 1.5 years). I thought it sounded like a loose valve, but it's the silly pump again. My indy is replacing it today.

Stevo · #7 09-20-2007, 05:41 PM

Man, your hard on vacuum pumps

Better take a good look at the little "roller coaster" track on the timing device.

#8 09-20-2007, 07:01 PM

Quote:

Originally Posted by Stevo

Man, your hard on vacuum pumps

Better take a good look at the little "roller coaster" track on the timing device.

LOL, you are way ahead of me. I just got back from the shop and it turns out the vacuum pump is fine but the timing (IP advance) device is hosed, it has way too much axial movement (which is what I could hear clanking) and the cam is pretty scored up. With any luck my indy can get his hands on a new one (and a new thrust bushing) by tomorrow. If it get put back together, I need to drive it to chicago on sunday.

300Turbo · #9 09-21-2007, 09:59 PM

What is this vac. pump everyone is talking about. My 1987 300DT has 151,400 miles on it.

#10 09-21-2007, 10:08 PM

Quote:

Originally Posted by 300Turbo

What is this vac. pump everyone is talking about. My 1987 300DT has 151,400 miles on it.

Unlike a gasoline engine, diesels do not create vacuum in the intake manifold so they have a mechanical vacuum pump to support the power brakes and other components. It looks like this, and is bolted to front of your engine:

http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1CQ0J3JZ426P1BAXNL&year=1987&make=MB&model=300-DT-002&category=All&part=Diesel+Vacuum+Pump

The problem is, if they fail they can cause significant engine damage by getting small parts into the timing chain area. The design of the pump on your engine has be upgraded over the years, it's not a bad idea to make sure you have the latest version installed. If you search on vacuum pump here, you will find a few ugly stories.

vstech · #11 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.

#12 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.

C Sean Watts · #13 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 · #14 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.

C Sean Watts · #15 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.

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