161k Do I need to change my Timing Chain?, damaged Injection Pump Timing device - Page 2 - PeachParts Mercedes-Benz Forum

dieseldiehard · #16 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.

#17 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 · #18 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.

#19 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.

Stevo · #20 09-21-2007, 01:12 AM

Quote:

Originally Posted by Craig

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.

I think thats the first I have heard of a timing device going south. Wonder why. I had too pull one once and remember having a bugger of a time getting the timing chain off it and then back on. Your engine isn't ready for a chain yet is it.

Good luck.

Hatterasguy · #21 09-21-2007, 01:13 AM

Quote:

Originally Posted by Stevo

I think thats the first I have heard of a timing device going south. Wonder why.

403,000+ miles!

t walgamuth · #22 09-21-2007, 05:33 AM

Quote:

Originally Posted by Craig

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.

It happened to me too. So it is not that uncommon.

Tom W

t walgamuth · #23 09-21-2007, 05:34 AM

Quote:

Originally Posted by barry123400

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.

I agree with this. Never change anything you don't know is bad, mercedes parts are just way too expensive.

Tom W

#24 09-21-2007, 09:08 AM

Quote:

Originally Posted by Stevo

I think thats the first I have heard of a timing device going south. Wonder why. I had too pull one once and remember having a bugger of a time getting the timing chain off it and then back on. Your engine isn't ready for a chain yet is it.

Good luck.

Not sure, but he thinks it may be the thrust bushing behind it that got beat up when the first vacuum pump failed, when I saw it yesterday afternoon they were still trying to get all the down pins out the release the chain tensioner so they can slide it out. Now it has too much play front to back. The chain only has about 70K miles on it, so it's OK.

Stevo · #25 09-21-2007, 10:23 AM

Quote:

Originally Posted by Hatterasguy

403,000+ miles!

Ah, didn't notice that, I still hadn't heard of one going bad, now with Tom's story, thats two

Stevo · #26 09-21-2007, 10:31 AM

Quote:

Originally Posted by Craig

Not sure, but he thinks it may be the thrust bushing behind it that got beat up when the first vacuum pump failed, when I saw it yesterday afternoon they were still trying to get all the down pins out the release the chain tensioner so they can slide it out. Now it has too much play front to back. The chain only has about 70K miles on it, so it's OK.

I don't remember but I think the intermediate gears must be removed also, be interesting too see what those look like. That would be good if its only the thrust washer.

#27 09-21-2007, 11:08 AM

Quote:

Originally Posted by Stevo

I don't remember but I think the intermediate gears must be removed also, be interesting too see what those look like. That would be good if its only the thrust washer.

By "intermediate gears" are you talking about the chain sprocket (which does have to come out) or the drive gears for the IP (which come out the back, I think)? Anyway, since they are in this deep I'm having them replace the timing unit (including the sprocket) and the thrust bushing. They are not removing the IP, they just locked everything in place to (hopefully) not mess up the timing.

Stevo · #28 09-21-2007, 11:36 AM

Quote:

Originally Posted by Craig

By "intermediate gears" are you talking about the chain sprocket (which does have to come out) or the drive gears for the IP (which come out the back, I think)? Anyway, since they are in this deep I'm having them replace the timing unit (including the sprocket) and the thrust bushing. They are not removing the IP, they just locked everything in place to (hopefully) not mess up the timing.

The "intermediate gears" (2) drive the oil pump and IP .there is allot going on behind that timing device and its all gota come out in the right order, I remember witting too this forum to figure it out

I put the shaft that drives the oil pump in upside down.

87tdwagen · #29 09-21-2007, 01:35 PM

I would check for stretch the eyeball method first and dig in deeper if not happy with those results. I followed the often mentioned procedure of lining up the camshaft and crank marks on mine at 220k, original chain and they lined up to Zero eyeball stretch, if I had more than 2 deg I would have gone into it per the FSM.

Just make sure to do it multiple times and average your readings, I did mine 5 times over each time showing zero so I'm not concerned. Eyeballing it should get you to within 2 degrees of precision. Since the tolerance limit is 4 degrees I'd recommend checking it with a dial indicator if eyeballing it gives you 2 degrees or more of stretch.

#30 09-21-2007, 01:49 PM

Quote:

Originally Posted by Stevo

The "intermediate gears" (2) drive the oil pump and IP .there is allot going on behind that timing device and its all gota come out in the right order, I remember witting too this forum to figure it out

I put the shaft that drives the oil pump in upside down.

OK, I'm not messing with the IP drive now, the IP isn't even coming out, just the bushing on that shaft (from the front). On the 617 turbo, the oil pump drive is a chain, not a gear drive like the 616.

Edit: on the 617 turbo, it looks like this: