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  #31  
Old 05-16-2008, 07:19 PM
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Don't beleive everything you hear

You have an ultra modern engine in the 617. In the old days they could fix a Model A Ford with anything, even a slab of bacon was at times stuck between rod and crank and made to go. Not with a 617. Never! It has to be total perfection or it is junk. Hate to say it, but short of a complete rebuild your engine is, well not junk, but lets say a good boat anchor. I think that is the only sensible way to look at it. How good is the rest of the car. That is where I think you should be looking. Is it really worth putting thousands in to it?

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Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!
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  #32  
Old 07-20-2008, 04:24 AM
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as an update - all 5 rod bearing were found to be scored, or 'toast'. But it is very early and seems to be worth replacing. The worst bearing still had close to 1/3 of the journal surface uncathed, and no bearings actually 'spun' in the true sense.

main bearings that I checked so far were unharmed.

now how do I get that dagged crank outta there w/o messing up the timing?
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  #33  
Old 07-20-2008, 05:31 AM
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Originally Posted by jt20 View Post
as an update - all 5 rod bearing were found to be scored, or 'toast'. But it is very early and seems to be worth replacing. The worst bearing still had close to 1/3 of the journal surface uncathed, and no bearings actually 'spun' in the true sense.

main bearings that I checked so far were unharmed.

now how do I get that dagged crank outta there w/o messing up the timing?
Allright lets go from the begging of how this happend to everything that it affects.

First off, oil is pressurised and forced through the crankshaft and it goes inbetween the bearings and the crankshaft, creating a thin film of oil that the bearing rides on. Now when you devolope a rod "knock" or spin a bearing, what happens is your increasing the clearances between the crankshaft journal and the bearing. What happens when a bearing gets worn down, is it increases the clearance between the bearing and crank, causing the oil film to "splash" out and lets the crankshaft hit the bearing, and every time the crankshaft hits the bearing it smooshes it out abit more increasing the clearance until the oil cannot hold any pressure at all.

Now the layers on a crankshaft bearing are comprised of a thick top layer of alluminum (on nitrided crankshafts) or a tin alloy. The second layer is copper and the backing is steel. This allows the tin to be beaten off until it gets to the copper, (wich you would then have a rod knock) the copper is much softer than steel, so its your last chance before your crankshaft is scored by the steel backing.

When you spin a bearing the crankshaft has touched and grabbed hold of the bearing, and literally "spun" them inside of the rods (or main bearings). After this happens, you may get a rod knock, and more likely than not it will score the crankshaft. What you must check before you put the bearing caps back on with new bearings (if the crankshaft looks ok) is check the ID of the connecting rod for out of round and for it to be too large (Because it will enlarge the clearances and may spin the bearing again).

A crankshaft can be ground down any number of times some crankshafts can be ground 5 or 6 times, depending upon what the manufacture says.

To me that looked like flakes of the top layer of the bearings. and because they are flat they must be rod bearings. (wich makes sence because your rod bearings are missing flakes it looks like in the pictures you showed).

I suggest you drop the crank, get all new fresh bearings check all of your connecting rods and main caps. Grind your crank (if needed) or get a new one. slap a new rear main seal in there and thwo your pan back on.
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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

Last edited by Cervan; 07-20-2008 at 05:37 AM.
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  #34  
Old 07-20-2008, 09:56 AM
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Originally Posted by jt20 View Post
main bearings that I checked so far were unharmed.

now how do I get that dagged crank outta there w/o messing up the timing?
Pretty hard to do all that work without retiming the IP plus its allot easer to learn with the engine out where you can get to things, maybe time for a new chain also?
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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"
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  #35  
Old 07-20-2008, 10:51 AM
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hello, i have been following you're story because i think i am in the same boat, mine came home from a half hour freeway (65-70 mph) trip and now goes knock knock. do you think you're (or we) going to look at the pistons and cylinder bores "while you're in there". You pulled the motor after looking at those lovely rod bearings? did you do a compression check?
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  #36  
Old 07-20-2008, 12:02 PM
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WWJD if he had his 617.95 out of the bay?

Sloppyjoec, My issue is a little different. There was no knock presesnt which provides me a much higher chance of replacing the crank and bearings with success. As Cervan was explaining, my clearances in the rod bearings have not yet been worn to a state that allows for 'slapping' of the crank surface against the rod bearings. There is a good chance that my rod caps are still undistorted.

If you have a knock present, you need to get under that car with a stethoscope at least, and listen for noises against the upper oil pan. You can drop the lower oil pan to check the bearings on #2 cylinder / rod to confirm damage before engine removal. (#1 can also be done, but must remove oil pump).

I have done a series of compression tests before taking the engine out and deciding to fix it. I agree with you completely, i would totally be wasting my time if I needed an entire shortblock.
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  #37  
Old 07-20-2008, 12:10 PM
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Quote:
Originally Posted by jt20 View Post
WWJD if he had his 617.95 out of the bay?

Sloppyjoec, My issue is a little different. There was no knock presesnt which provides me a much higher chance of replacing the crank and bearings with success. As Cervan was explaining, my clearances in the rod bearings have not yet been worn to a state that allows for 'slapping' of the crank surface against the rod bearings. There is a good chance that my rod caps are still undistorted.

If you have a knock present, you need to get under that car with a stethoscope at least, and listen for noises against the upper oil pan. You can drop the lower oil pan to check the bearings on #2 cylinder / rod to confirm damage before engine removal. (#1 can also be done, but must remove oil pump).

I have done a series of compression tests before taking the engine out and deciding to fix it. I agree with you completely, i would totally be wasting my time if I needed an entire shortblock.
As long as your crankshaft mic's out good (you need to measure it, the surface can be reconditioned) you can simply buy new bearings and have the crankshaft (or you can do it yourself) polished to remove the surface blemishes. You also need to check for "ovaling" of the crankshaft, so check it in three or four points on each journal.Retiming isnt that bad and its so much better to know that everything is good on the bottom end than to have something go wrong just after you got it back together. As long as you did not spin any bearings, your rod end caps will be in perfect shape, the spinning of the bearings removes material from the ID of the rod's.

All you need to do is make sure that your clearances are correct, the crankshaft is smooth, and you have plenty of oil pressure and you will have no issues.
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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

Last edited by Cervan; 07-20-2008 at 12:16 PM.
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  #38  
Old 07-20-2008, 12:14 PM
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Oil pressure was normal and there is plenty of unblemished surface on both bearing sides on all 5 rods.

I already have a new crank and bearings on the way. Regrinds are not worth the time and money. Few shops are set up for metric regrinds and have lots of trouble with clearances after nitride hardening b/c the metal swells after the procedure. Metric motors makes a regrind - that is the only one I would buy ever!
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  #39  
Old 07-20-2008, 12:18 PM
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Originally Posted by Stevo View Post
Pretty hard to do all that work without retiming the IP plus its allot easer to learn with the engine out where you can get to things, maybe time for a new chain also?

Chain stretch is good - it actually looks like a new chain!! sweet. What do you think about zip tieing the cam sprocket to the chain - removing the rockers - pulling the sprocket - removing tensioner - then trying to get that crank out?

I am tring to do this with all the pulleys and balancers still mounted.
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  #40  
Old 07-20-2008, 12:22 PM
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Quote:
Originally Posted by jt20 View Post
Chain stretch is good - it actually looks like a new chain!! sweet. What do you think about zip tieing the cam sprocket to the chain - removing the rockers - pulling the sprocket - removing tensioner - then trying to get that crank out?

I am tring to do this with all the pulleys and balancers still mounted.
Your planning on removing the front pulley on a bench vise? I think you could get enough slack if you did all that.. it would be much easier just to put a 2x4 inbetween the crankshaft and the block then get your breakerbar on the front pulley bolt. This is all with the engine out of the car correct?

You could try a 3/4 air impact gun, that may do the trick.
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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.
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  #41  
Old 07-20-2008, 12:31 PM
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I am doing all of this with no air. The engine is out.

that pulley needs to come off now, huh? Was hoping to get a pulley with the new crank. You are right.
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  #42  
Old 07-20-2008, 12:34 PM
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Quote:
Originally Posted by jt20 View Post
I am doing all of this with no air. The engine is out.

that pulley needs to come off now, huh? Was hoping to get a pulley with the new crank. You are right.
Oh, im sorry if your getting a new pulley with the crank by all means leave it on there lol. i just figured you were going to transfer it over.
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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.
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  #43  
Old 07-21-2008, 01:25 AM
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Quote:
Originally Posted by jt20 View Post
Chain stretch is good - it actually looks like a new chain!! sweet. What do you think about zip tieing the cam sprocket to the chain - removing the rockers - pulling the sprocket - removing tensioner - then trying to get that crank out?

I am tring to do this with all the pulleys and balancers still mounted.
I think it might be difficult to do this job without losing timing for one reason or another. Wouldn't it be better to feel confident the crank, IP and cam are all in the right position before installing the engine?
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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"
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  #44  
Old 07-21-2008, 01:32 AM
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Originally Posted by Stevo View Post
I think it might be difficult to do this job without losing timing for one reason or another. Wouldn't it be better to feel confident the crank, IP and cam are all in the right position before installing the engine?

it would, indeed. I dont know what my fear of timing the IP is all about, never done it before.

today I removed the camshaft and left reference markings to the chain after setting the #1 to TDC. Thats FSM and the best I can do. As long as I dont move the pistons from here on and the IP doesn't move, I should be able to do a straight swap.... right? If not, I'll learn how to time the IP.

I have read about the drip method - it seems very faulty - any suggestions on preferred methods?
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  #45  
Old 07-21-2008, 04:49 AM
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Originally Posted by jt20 View Post
it would, indeed. I dont know what my fear of timing the IP is all about, never done it before.

today I removed the camshaft and left reference markings to the chain after setting the #1 to TDC. Thats FSM and the best I can do. As long as I dont move the pistons from here on and the IP doesn't move, I should be able to do a straight swap.... right? If not, I'll learn how to time the IP.

I have read about the drip method - it seems very faulty - any suggestions on preferred methods?
i had to time my engine by the "welling" method awhiel ago when i lost my timing. i took each of the lines off going to each cyliner and cleaned out the ports on the injectionpump the best i could with compressed air. then i took some dry paper towel and put it in a cone shape down into the hole. i then turned the chain over until i saw fuel welling up in that hole. That means that was firing at TDC on cylinder number 1 and i put everything back together

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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.
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