Timing Chain SOS - please help!!
 

Replacing a timing chain in '93 300D (OM602). The kit did not include a temporary master link for the feed through portion of the show, and I was afraid to use the master link unpeened, lest it fall off in the nether regions of the engine. So we fed heavy hanger wire through the holes, bent it up over the chain and hammered it down as flat as we could.

We got most of the new chain fed through, and with about one foot left to go, the chain bound up and would not continue. We put a lot of torque on the crankshaft but it would not budge. Back and forth several times, no help. Tried gingerly spinning the starter to free it, no help.

Soooooo...we tried to back the new chain out and start over - but it bound up going out too. There is about 4" of play between the two bind points. The chain is stuck and so are we. I am assuming there is insufficient clearance for our temporary pins through a guide somewhere that we can't see.

Anybody been-there-done-that? Any guidance would be appreciated - if not we are scr*w*d

Has tensioner been removed? Maybe moving the rail will help.

Not me!
 

I haven't been there or done that. But you are in a difficult spot no doubt. I always think a good place to start is to get an assembly view of the problem. So I chased this down on your vehicle from the "Russian site" It is a decent drawing of the timing and perhaps will give a help. Check it out. Scroll down on the page to pick up the detail parts drawing.

http://www.detali.ru/cat/oem_mb2.asp?TP=1&F=140134&M=603.971&GA=722.367&CT=M&cat=503&SID=05&SGR=015&SGN=01

X-Ray Vision of the Timing Case
 

Whoa ! Un-Happy Times.Sorry for your difficulty

Looking at and Measuring Mine (both)
I'll do the "California Psychic Prognostication".

"Your homemade TC attachment device initially "Bound" on the Bottom Lip of the Guide Rail that is used by the Tensioner to keep "Slack" out of the TC system.Your further efforts (WITH the STARTER) may have "Deformed" the
"Hanger Wire" sufficient enough to Prevent the "Connection" from passing
back over the Dual Crankshaft Sprockets."

EDIT:
On JunKYarDJIM's RU diagram...#50's bottom edge is where the "Crystal Ball"
says your initial "Bind Up" occurred.
(Of course it may have "Grabbed" some part of the Dual Crankshaft Sprockets)

Hopefully, One of the Professional Techs that visit Tomorrow Morning will
have an answer to your problem.(They may have previous experience
"Correcting" the same sort of difficulty, imposed upon them by another owner.)

However, Your assigned reading material for this evening are FSM procedures
for R+R the Timing Cover.

A foot to go suggests it's binding in the transition from the crank sprocket to the tensioner guide. Thankfully gsxr has this picture from a 603 which should be identical to a 602 for this situation -

http://www.w124performance.com/image...ront_view1.jpg

If I had to guess, though, I'd say it's binding between the IP sprocket and lower guide or lower guide and crank sprocket. If you're really stuck, pull the vacuum pump and basket. It might give you a clue as to what's going on or at least a new leverage point to tease through/back the chain.

Might also be binding by oil pump chain where chain width clearance is tightest.

Sixto
87 300D

Update and thanks
 

Thanks to all who chipped in with advice and suggestions. I cannot tell you how much I have learned from these boards since I found this site last year.

After reading all the input and studying the diagrams, we replaced the tensioner spring, thinking that if it was binding up between the tensioner and the crankshaft gear, this would pivot the base of the tensioner and provide more clearance. This operation was successful, and we were able to thread the chain almost to the top.

Almost home....We have hit another binding point and we are stumped. We can see the temporary pins coming up along the tensioner, and they are moving freely.

What else could be binding up??? we have about 4" of chain left to feed.

Tensioner is out.

Maybe you have some bunched-up chain in there... if you are sure you can keep your temporary pins free, maybe you should back it out pretty far before going forward again. Another possibility... with all the difficulty you've had so far, is it possible your cam got out of time and a valve is hitting a piston?

Remove the lifters to close the valves, if you think they are touching piston.

End of the story
 

The second binding was the valves hitting the piston head. Turns out the rockers on the used motor I had just installed were about 175* out of alignment. So much for "it was running great before I pulled it from the car."

Caveat emptor.

I don't understand this about the rockers being out of alignment... I fear we haven't heard the end of the troubles yet.

The saga continues.....
 

JonL your words were prophetic.

So we finally got the timing chain reassembled, crank at 0*, camshaft marks lined up, buttoned it all up.

It starts with difficulty, runs very rough, lots of smoke, will die if I take my foot off the accelerator. Not the look we're going for. Threw in the towel at 2000 hours last night.

Bit of background: '92 300D with 415K, bent a rod. Found a OM602 from a '93 at a local junkyard (that in and of itself is amazing for Maine). Understanding the risk, I bought it because (1) head looked brand new & (2) the IP was intact and apparently untouched. JY man assured me the car was running well before he pulled the motor and disposed of the car. We had hoped to get this cab on the road in about a week. LOL

Swapped out bolt-ons, fuel injectors, glow plugs, new filters, now new timing chain. Now I'm thinking IP timing. Is there a DIY out there on adjusting IP timing on a 602?

Look under resources, articles, at top of page. "Removal of 603 injection pump" reviews timing. What part are you calling a rocker?

Thanks for pointing me in the right direction
 

By rockers, I was referring to the camshaft lobes

If the valves did hit the piston head, there is the possibility that the valve stems or heads are either bent, or damaged, and are not closing correctly, which may account for the poor running you are experiencing. Good luck

Compression test.

I'd agree that camshaft and/or IP timing is your issue. For IP timing, the easiest method, which also happens to be the factory method, is to use the A/B timing lights via the port in the side of the IP.

You connect it to the battery, the probe and slowly rotate the engine until both lights illuminate. Then, read the crankshaft damper. If it's not 15 ATDC, adjust IP until you get 15ATDC.

Done.

There are two of them in the rental pool.

When you replaced the timing chain, did you check the cam timing? Simple to do, instructions elsewhere and should be easy to find.

I'm concerned that the valve was hitting the piston as you were rolling in the chain. This means that either the engine was out of time when you bought it, or it got out of time while rolling in the chain. Either way, it was most critical that you ensured the cam timing was correct when you finished the chain replacement. If you started the car with the cam timing out by enough (not much), you've bent the valves and the head will have to be removed. Here's what I suggest:
1. Pull the valve cover, check the cam timing. If it is off, correct it.
2. If the cam timing was off and is now correct, might as well try running the engine. You've got nothing to lose.
3. If the engine runs properly, don't worry - be happy.
4. If the engine runs poorly, do a compression test. If bad, pull the head. If good, check injection pump timing (instructions elsewhere).

Good luck.

To clarify:

I am sure the camshaft is properly aligned; we were most careful to check this before we closed the chain. So I know that the crank and cam are in sync. This leaves the IP - or (shudder) damage to the valves, head and/or pistons.

I am a newbie to the boards, how does one go about renting the A/B timing tool? Meanwhile, we will check compression (cold since I can't run it - yes I already know what you're about to say)

And again my thanks.

'97 E300
'95 E300
'92 300D
'92 300D (the sick one)
'95 Suburban 6.5L Turbo

Go to the tool rental forum and the first and only thread has the list of the available tools and who rents them. Contact the member via PM and make the arrangements.

The compression check is fine if you're just interested in seeing if all cylinders are close to each other and you don't have one or two that are hurting.

Also, I'm sure you don't want to type those vehicles every time you post. Go to "User CP" and click "Edit Signature". Put them in once.........

OK... here's a thought. If the original timing chain was stretched 5 degrees, and you were at TDC but on the intake stroke, you'd think the cam was out 175 degrees. So you rotated the cam 175 degrees, now the marks line up, the valves won't hit, everything is cool... except the injection pump thinks you're on the intake stroke when you've changed the valve timing to make it now the compression stroke. In other words, your IP is now 180 degrees out. Fix is simple, and you don't have to screw with the IP. Set the engine to TDC, with the marks on the cam lined up also. Rotate the crank clockwise one turn and one turn only until you are again exactly at TDC... now the cam mark should be 180 degrees away from where it was. Remove the tensioner. Take the gear off the cam. Loosen the cam bearing caps a lot so the valves are all closed. Rotate the cam 180 degrees to line the marks back up. Put everything back together with the cam marks lined up and... voila.

Do this only if you think you rotated the cam almost 180 degrees to get the marks lined up during your previous work.

Do Not Rotate Engine Backwards (CCW) !
 

Jonl,

Your Statement:
"Rotate the crank one turn and one turn only back to exactly TDC.

I realize you typed "Forward",BUT it appeared as "back"
(That 9 year old in Latvia "Hacked Into" the Stream and altered your reply)

That damn kid got me again... Fixed his mistake. Thanks for the heads up!

Cab 5 saga continues....
 

Hi gents,

OK - after turning the crankshaft forward one rotation, re-aligned the camshaft, buttoned it all up and - nothing. Now it cranks but won't fire. Checked for fuel at the head of the injectors, fuel present. Fuel lines to/from secondary filter full, no air. Kill switch on the IP is up and all vacuum lines properly connected.

I am thinking that even if the IP timing is still off, it should still combust - it did when it was WAY out and the 'pistons were being introduced to the valves'. Surely we should be getting combustion now.

Any insights??

Well, you decided to ignore my previous advice regarding obtaining the A-B lights and took advice regarding rotating the crankshaft 360 degrees.

You had no data to suggest that the IP/camshaft relationship was incorrect other than the fact that it ran roughly. This is certainly not confirming evidence of 360 degree error in the crank/IP timing.

So, now you have a vehicle that previously ran but didn't run well..........and you currently have a vehicle that doesn't run at all.

Which advice was correct?

If you used the starter to try and bump the chain free from the crank sprocket with the chain broken and laying halfway down in the front cover than you have no business attempting a timing chain r and r in the first place. You probably bent some valves when you cranked the motor without any timing chain connected to the cam. Not trying to sound like forcedinduction (just a good natured jibe) but seriously it sounds like you should have done alot more studying up or found someone with some experience to help you out on this one. I hope for your sake that you didn't damage anything seriously and it is just a matter of everything being out of time which it certainly is at this point.

The idea that the IP was about 180* out of alignment sounded logical and was easy to verify. Brian, I did not discard your advice, only tried the simple answer first. I guess the next step is to rent the AB light - I'll be doing that top of the week.

The OP did have a reason to suggest the IP/camshaft relationship was incorrect, as he claimed to have rotated the cam 175 degrees independent of the crank while changing the chain. Nonetheless, my "advice" was phrased as a "thought," and not a diagnosis with any certainty. It also contained the following disclaimer:

Anyway, I've sent the OP a PM suggesting that he take a more methodical approach, starting with a compression check. Then checking to see if his IP timing is near correct or near 180 degrees out or somewhere in between the two.

PS: If the advice to use the A-B lights failed to lead to a running car, would the poster who suggested doing a compression test first jump in here and say "See, I told you my advice was better...."?

Ace, with the crankshaft and the cam on thier timing marks you should be able to see the timing tang on the ip with its access plug removed, the tang will be in center of the hole if you are in time. A mirror helps.

http://www.w124performance.com/images/OM603_injection/IP__RIV_tang.jpg

You can absolve yourself on here until your heart is content.

However, without any real data on IP timing, you took a running engine and turned it into a paperweight.

The A-B lights would tell you, in about two minutes, if you're close on timing or 180 degrees off.

This approach is also perfectly acceptable for a quick check without the lights.

There was no expectation of a "running car" when the A-B lights were used. It was to be utilized as a diagnostic tool to determine where the IP timing is relative to the crankshaft.

As such, it would have fulfilled this task perfectly.

BTW, there's nothing wrong with a compression test........when you get done, you've got a bit more data........and you haven't harmed anything.

And is exactly the approach I suggested to the OP in my PM to him earlier today.

I strongly discourage communication via PM. If you take him down the wrong path........there's nobody to solve it and there is no possibility of recreating the events. The full onerous of a paperweight will be upon YOU.

I very rarely provide advice via PM.........only in the case of a single post response that will fix the issue. Anything that requires any thought or testing is directed to the forum.

Thank you for your permission. Perhaps I will take you up on that if I ever feel I must.

It was clear from the OP's saga that the timing of the cam had been in question. And changed by just about 180 degrees. Perhaps you failed to read that posting.

Two minutes plus about a week for shipping. Plus it will NOT tell you by itself if you are 180 degrees off. (I'll leave the proof as an exercise for the student.)

I have an idea... Let's try to help the guy fix his problem? ;)

Point well taken. So, here it is. Get out your red pencil.

And finally:
Brian, I hope this meets with your approval.

It's fine.

However, there is no question that the engine will start........it already did.

And, since it did.......without too much effort.......I'd dispense with the compression test. Unless one cylinder is dead, it can't explain the rough idle.

He probably doesn't have the equipment for a compression test anyway.

Thank you. :rolleyes:

The condition of the engine is totally unknown... it was purchased used and never operated by the original poster prior to replacing the chain. There are no data to suggest that the compression is good on all of the cylinders. In addition, there is the real possibility of bent valves based on the information posted that the engine would not continue to turn by hand because the cam timing was off enough to cause a valve to contact a piston.

There is a data point (post 18) that indicates that he in fact does have the equipment required to perform this operation.

;)

You asked........




Then, by all means, more data is always helpful.

Ace Taxi: Did you start or attempt to start the engine after putting it in the car? If so, how did it operate? Why did you replace timing chain?

Gentlemen,

The engine came from a '93 with approx. 150K miles, per the seller. Has been out of the car for a couple of years. IP intact, all other bolt-ons were removed. PO stated that the engine was running fine before he stripped the car for salvage.

After we had the motor in, it ran, but very very poorly, rough idle, much smoke, no pick up, temp spike on idle. Valves may have been hitting at that point. Given well documented TC stretch issues w/OM602 as discussed elsewhere, I decided to change out the timing chain. [It was during this changeout that I ran into trouble and first started this thread.]

After replacing TC, car ran worse than before, would not idle - although clanking sound (which I initially took to be a loose TC and has since been suggested was the valves hitting) was no longer present. Turned the camshaft 180* per JonL and that brings us to present condition.

Assuming that the IP timing is more than a few degrees off, I am going to have to remove the IP to fix it, correct? In that case, does it make any sense to simply pull the IP from the old motor, line everything up, and install? That motor was running great until we bent a rod at 415K mi.

Alternatively, is there any way to compare the two pumps so as to diagnose and align the pump that is currently on the engine? I know there is a DIY on removing the IP; I have studied it carefully. Is there one on adjusting the IP?

As each day passes the pressure to get this car rolling increases. Cab 6 ('97 E300) is still in the body shop for repairs following a hit by an F150) during a snowstorm, and C2 ('95 Suburban) just got towed in with a blown head gasket. Don't you wish you were me?

Can we please stop making assumptions? As suggested by Owell in post #29, it's time to go to the IP, remove the plug to the port on the left side, rotate the engine until you can feel/see the notch in the window, read the crankshaft damper, and check the camshaft for stroke.

As suggested above, this can be done today, without the A-B lights.


Also, since you have the equipment for a compression test, how about getting some figures........??

I agree with Brian. You'll only solve this car's problem with a logical, methodical approach. There are two big unknowns -- the engine condition, and the IP timing. Both can be determined relatively quickly and easily. If it were me, I'd want to know if I was wasting my time with the engine and I'd do the compression test first. Of course, I might end up magically converting a paperweight into a lawn ornament or a chicken coop. Maybe we can give Brian a shot at that! ;)

Seriously, you can check either thing first... You will absolutely need to set the IP timing before the car runs well, and knowing where you are now is the first step to that.

Well.......let's hope for the best......maybe it's just IP and cam timing........

Data
 

Here's the data:

With tang in the middle of the port, crank reads +22*
Cam mark seems to be near 180* +/-20*

Compression test either later or tomorrow

Again, I am grateful to all for your input.

+22* is 22* ATDC or BTDC? Spec is 15* ATDC so 22* is not too far off. Might not be within the adjustment range of the IP. Might have to move the IP timer a spline or two to get it in range.

What do you mean cam timing is 180*? Cam timing when the IP lug is showing is irrelevant. Give the crank another spin to align the cam notch with the cam tower then read the crank pulley again.

Sixto
87 300D

To clarify:

By +22* I meant 22* ATDC, that is, the hash marks to the RIGHT of 0* as you look down on the crank pulley.

Looking down at the pulley, the marks reading left to right start at ATDC. In other words:

ATDC 30 20 10 0T 10 20 30 40 BTDC

I don't recall exactly the marks, and the "ATDC," and "BTDC" aren't actually marked.

Here's what you want it to look like when the pump is timed properly:

20 * 10 0T 10 20 30

0T is TDC. the * is where you want the pointer on the front cover. The number one cam lobes should be pointing more or less away from the valves, in other words, valves closed.

Then if I have the nomenclature correct, the crank pulley reads 22* BTDC with the tang visible.

30 20 10 0 10 20* 30

I will double check this and try to snap a pic to eliminate any doubt.