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1914 Mercedes 28/95 hp, 83' 300SD, 93' S420, (three) 94' S420's, 95' S500 & 96' S600
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Discussion Starter #1 (Edited)
Are you really worried about the Chain Guides and Timing Chain?

Do an inspection..... can be accomplished in a garage or car-porch!

1. Pick up an OEM lower oil-pan gasket......
2. rent 2 jack stands and hyd. jack or small eng-lift unit.


Then, remove the LOWER PAN and look for the tell- tale nylon debris of guides being eaten up by the chain!.

1. Lift the vehicle to allow access below same and support with good vehicle support stands...DO NOT WORK BENEATH ANY VEHICLE WHILE SUPPORTED WITH ONLY A JACK OF ANY KIND!
2. If this is a 119 engine en an 140 chassis, you will need to remove the motor mount bolts (keep them marked as to where they are from (some mounts have a specific bolt per hole, etc). Now, using a motor hoist, we use the bracket above the upper raduator hose to attach the hook and raise the engine 2-3 inches...ensuring the cable at rear of engine is not affected while raising.
3. Drain the existing engine oil, and detach the three ty-wraps holding a small wiring harness on rear of lower oil pan. Easily raise the small harness above...out of the way. Remember you are removing eight quarts of oil.
Now the lower oil pan has easier access to the allen bolts in front of lower pan for removal. After lowering the pan, move it to a location for inspection, like the work bench, or adjacent stool.

Following are suggestions for findings:

No debris: :D
Please keep in mind, if there is no debris. Great, then you have a reasonable expectation that the nylon guides are intact. Make sure to inspect the oil pump pickup horn and clean the horn's screen of any residue. As a further check, do a good visual of your oil pump and the drive chain.

Yes Debris: :eek:
1. Don't panic, this is what has possibly occured... your chain has damaged a guide and is stretched, thus causing the damage to begin due to flapping and hitting the guides. You have the necessary info on this site. Look over this site and do a search regarding Timing Chain/guide repacement. The task has been done here by several members. If you feel that can accomplish this task, then plan, gather resources and follow through. The chain being replaced is your decision of course. If you are going to keep this vehicle, after getting the timing cover removed..... think about your previous decision to change the chain or not? That expenditure will be the best money you have invested in your Benz and also BE SURE to replace all of the chain guides, not just this one or that one, etc. Suggestion:During replacement of the Guides.... make sure to put a DAB of Clear RTV on the tip of each Guide Pin and top Rim of same to ensure block and cover integrity from oil leaks. :thumbsup:

2. Also suggest removal of at least one valve cover. With the/both valve cover(s) removed, look closely at the roller(s) of one of the links. Does it appear damaged... indents, any dings or major loss of sheen in the center of the roller? Now look closely at the tip of the gear tooth/teeth. The teeth of the cam gear sprocket are slightly flat at the tip when new. As the gear wears the teeth will over time loose the flat and slightly deteriorate to a rounded appearance to finally when severely worn to SHARP appearance. When the gears teeth become sharp there is an expectation of the teeth to break and/or the timing chain to jump position. If the chain jump position or breaks....well, this will cause damage to valves and pistons as MAJOR DAMAGE :surrender:

The engine can compensate for chain stretch of more than four degrees. If it gets stretched, then you may experience the common "louder" rattle at start up and then the rattle, ticking will disappear when the Tensioner pumps up with oil and takes up the slack. Once the chain get too long (stretch's) for the Tensioner to pick-up the slack, the chain will start flapping and whip the guides at start up and hard acceleration, etc. Then the guides may be damaged and as the damage accelerates rapidly is dependent upon your driving habits and further guide damage that causes more damage from the chain, etc.

A simple inspection at intervals easily by removing the passenger side valve cover is recommended as a precaution. Also a removal of the lower oil pan would reveal a variety of items that could be easily overlooked otherwise.

As a note, the Timing chain can easily be replaced. This is without removal of the frontal timing cover. :thumbsup: Before doing so, it is recommended.... an lower oil pan inspection, to ensure there is not guide damage (evidence by possible nylon debris in lower pan, etc).

Regards, Dietrich and Robert
 

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1994 s320
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I respect your knowledge,and i know lots of people have worries ,myself included ,about timing chain snap,but i have two friends who's like you are experts and in their 30 years of experience ,they have never seen this to occur:rolleyes::confused:

I did replace TC on my diesel ,thats was an easy job around 2 hrs ,no special tools (chain press) required-two hammers -tap tap tap :)
 

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I respect your knowledge,and i know lots of people have worries ,myself included ,about timing chain snap,but i have two friends who's like you are experts and in their 30 years of experience ,they have never seen this to occur:rolleyes::confused:

I did replace TC on my diesel ,thats was an easy job around 2 hrs ,no special tools (chain press) required-two hammers -tap tap tap :)
Try reading again - timing chain snap is not the subject.
 

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'14 E350, '07 CLK350, '01 SLK320
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Dietrich, I have a question for you. It is not so much about the t-chain, but about removing the oil pan on the M119 in a W140. I have a leaky oil pan gasket on my S420 so I was thinking about doing the t-chain check and replacing the gasket at the same time.

Now to the question: Do you have to loosen the motor mounts and host the engine to get the pan off or does that just make the job a bit easier?
 

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1914 Mercedes 28/95 hp, 83' 300SD, 93' S420, (three) 94' S420's, 95' S500 & 96' S600
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284 Posts
Discussion Starter #5
Lower Oil Pan

When you do lower the pan, you will notice the oil pump's pickup horn extends down to just above the bottom of the lower pan.

By raising the engine only a few inches, not only will you be able to remove the oil pan bolts easier with an allen.

But you will easily lower and move the pan clear of the oil pan horn and forward oil pump chain gear

Hope this helps... also... when raising the engine- go slow and raise it only as high as you actually need to access the bolts. When you actually move the pan, you will see what I am referring too! :thumbsup:

Regards, Dietrich
 

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1914 Mercedes 28/95 hp, 83' 300SD, 93' S420, (three) 94' S420's, 95' S500 & 96' S600
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284 Posts
Discussion Starter #6 (Edited)
Plausible solution to T-Chain Condition Questions....

I respect your knowledge,and i know lots of people have worries ,myself included ,about timing chain snap,but i have two friends who's like you are experts and in their 30 years of experience ,they have never seen this to occur:rolleyes::confused:

I did replace TC on my diesel ,thats was an easy job around 2 hrs ,no special tools (chain press) required-two hammers -tap tap tap :)
As deanyel noted (thank you deanyel), this post has nothing to do with A CHAIN SNAP.......​

Dutch, Robert and I have a few years under these Dutchland hoods and also worked as Technicians in Diagnostics. Robert is the only one of us with board level diagnostic experience and design of CAN and data transfer systems. Between the three of us, we are having fun working on our personal cars and others in contact with us and Dutch's original shop..

The Post is simply a plausible solution to many PM questions about getting peace of mind regarding the condition of their chain.​

ALSO, In our few years of experience... we have seen several Mercedes Power Plants "JUMP TIME" and also on the AUTOBAUN....... it is a spectacular event.

But, anytime/anywhere an engine jumps time (as in when the timing chain jumps a tooth or two or more) the is a definite possibility of a true union of the face of a piston having a CLOSE ENCOUNTER with a VALVE or TWO OR THREE.

Have even seen a piston end up showing it head out the side of a block. Amazing what can happen at 150 mph and a chain tensioner fails or a few guides give it up and all of a sudden there is a whole lotta chain with not enough teeth to hold on too.

Hope the explanation assists your MINDS EYE...

Thanks for sharing the perspective of a chain snap and ease of chain replacement!

And yes, a snap is not likely.....​

but a Jump in Timing must be avoided!​


Dietrich​
 

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1914 Mercedes 28/95 hp, 83' 300SD, 93' S420, (three) 94' S420's, 95' S500 & 96' S600
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Discussion Starter #8
120 engine

How about the 120. Mine has 244KM
The lower pan is always the easier inspection recommend if there is a concern regarding nylon Guides and detoriation.

Due to the cranks location, it is not easy to see the T-chain with the lower pan removed.... the valve cover is the easier way to examine the chain in detail as to a link for a good view of roller, etc.

Regarding pan removal, the nylon debris will not always flow with the lubricant in an oil change. If the engine is noisy and you are concerned, or you have an higher KM/ US mileage.... make that oil pan inspection and put your mind at ease.

Hope this helps, Dietrich
 

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'14 E350, '07 CLK350, '01 SLK320
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By raising the engine only a few inches, not only will you be able to remove the oil pan bolts easier with an allen.

Regards, Dietrich
I crawled under the car yesterday and now I understand what you were saying. What a job! :eek: It only leaks a few drops every few days and I think its going to stay that way 'till I have to do motor mounts or some other major repair. I would guess that would be about $400 worth of labor to replace a $5 part.
 

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1995 S500, 2001 E55
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Are you really worried about the Chain Guides and Timing Chain?


As a note, the Timing chain can easily be replaced. This is without removal of the frontal timing cover. :thumbsup: Before doing so, it is recommended.... an lower oil pan inspection, to ensure there is not guide damage (evidence by possible nylon debris in lower pan, etc).

Regards, Dietrich and Robert
is there really a way to do this without removing the timing cover? if so, is there any DIY write-up on how it is done? also how involved is the timing chain tensioner replacement?

thanks.
 

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1914 Mercedes 28/95 hp, 83' 300SD, 93' S420, (three) 94' S420's, 95' S500 & 96' S600
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284 Posts
Discussion Starter #12
Sorry for delay, missed this question with so much going on with Dutch's work-load and him being out of country for so long.

The alldatadiy.com website has an excellent write up on the...
Procedure to replace the timing chain with the front engine cover in place.​
This procedure is not, as many say "easy", nor is it Brain Surgery, you must utilize patience and good partnering with a friend if possible. Being I have very few friends, I have found alot of innovative methods and procedures. I am know for hacking into many MB operative system protocol (mainly because I wrote some of them) and always look at

How easy it is going to be and take things... One item/line at a time.

If you break things into little pieces, one bit at a time and it will all come together,

eventually

Regarding the tensioner replacement... as above...alldata will help as well..or:​
1. Anytime the tensioner or timing chain is involved on the 119, ensure to manually rotate the balancer (crank) to 45 deg BTDC (removal of spark-plugs makes this easier) and also, remove both valve covers and pin all four of the cams at the 6.5mm lock holes which should align at or very close to 45 deg BTDC crank position. I simply take care and ensure the crank does not move... but if you desire to lock the crank: Many folks use different innovative methods to ensure non movement. I have tried to just watch myself and use care to keep at least one cam always locked and make very sure the chain stays intack on sprockets(usually both exhaust cams and even wrap a ty-wrap around sprocket and chain) can work or another is as follows: If chain comes off/jumps and cam sprockets move without relation to original 45 deg BTDC position....

If an operational error occurs, crankshaft and four cam position misalignment is determined... then correction of timing is in order.

This is simply to ensure the crankshaft and the four 6.5mm cam holes align with both intake cams retarded
:thumbsup:

The lil inspection cover over the flywheel (drivers side, area of the starter if drive wheel were on right, etc). The engine will have to be raised a few inches to remove a small exhaust section to access the cover.... involving removing the two engine mount bolts on driver side, then cut a 2X4 about 6" and place just under the transmission front ring and using a jack...raise the engine about 2-3 inches. Contrary to alot of posts... with care , this IS NO PROBLEM! Loosen the left exhaust pipe at engine lower exhaust manifold flange and also at Y connection beneath passenger area. The small exhaust piece can now be lowered and rotated to remove same. NOW, the smaLL inspection cover can be removed to lock the flywheel (which will lock the crank from movement, etc).
2. It is easier to remove the right distributer cap with plug wires (lay over radiator), also nylon shield and also the rotor to protect same from accidental damage! This will allow easier access of tensioner, etc. It can be a lil tight access to work with tensioner.
2a.Above seems like alot... don't worry, it is actually easier than buying an engine hoist. Now... You will need to loosed the air pump and bracket holding same. Once the air pump top retaining bolt is removed, the pump can be rotated back and the bracket (three 13mm bolts) can be rotated a little and removed.
3. Behind the air pump holding bracket, you will find the chain tensioner. Now, remember the tensioner is a DEAD END oil passage device and when you remove it... a small amount of residual oil will come out and you will want to protect the alternator from the oil with a few rags covering same. We also find it easier to remove the top and lower air pump retaining bolts (leave the alternator attached if you like. I simply rotate the air pump vacumn switch and leaving the hose attached to engine block under the exhaust and lay the pump head down by the alternator.
4. The tensioner will have a 13mm bolt and behind same is a stud with a 13mm nut. Slowly remove both in sequence to allow the tensioner to evenly be removed. If this is the original tensioner, remember it has been in use a few years and you want to ensure any stress it encounters to minimal. The tensioner will in some instance require a little coaching to help removal. After removing it, take your index finger and press within the tensioner hole and ensure the tensioner rail is relaxed and moves inward easily. When you reinstall the tensioner (or replace same), ensure to use a long small diameter screwdriver or dowl to (minimal pressure) raise the tensioner rail (access from above, beneath the right exhaust cam chain area). The torque of the tensioner installation is 25 Nm (19 ft lb), remember that the tensioner MUST be reinstalled with EQUAL torque and the tensioner face is pressed even. Due to the restricted area, I have found that using an inch pound torque wrench makes this installation easier. The proper inch torque is 228 inch pounds. NO SEALANT should be used with the Chain Tension Gasket. Also, DO NOT PRIME the new Tensioner before installation. I have found that by giving a little leverage to the upper right chain (beneath the exhaust cam sprocket) this will raise the tensioner rail and allow the tensioner to be reinserted and the 13mm hex head bolt and 13mm hex nut to be reinstalled. Slowly evenly tighten both to bring the tensioner evenly to firm face pressure. The begin to bring the Tensioner to appropriate torque.
5. When finished, I would suggest removing the crank lock (flywheel area, if used). Remove the cam pins and then using the crankshaft nut... slowly rotate the engine for two rotations to ensure movement and after two rotations, the four 6.5mm alignment holes for 45 deg BTDC should be correct. This is just a recheck of chain tightness and alignment. Now, reinstall the valve covers and engine ventilation hoses, spark-plug wiring and distributor caps. Do not install the air pump OR poly belt as yet.
6. To ensure at valid installation with no oil leaks. Suggest turning the ignition key over without coil wires until the oil pressure gauge shows minimal movement. Once you notice a small blip of oil pressure, reinstall the coil wires and start the engine.
7. Monitor the temp gauge and inspect the Tensioner area for any leakage. After the engine reaches just over 80C, operate for a few minutes. Once satisfied of no leakage, shut the engine off. Once the engine area cools off, reinstall components in reverse order. I would suggest a small dab of Permatek-2 on first thread of all bolts. The torque of the airpump bracket bolts is 25 Nm or 19 foot pounds :D
8. Reinstall all components. After installation, ensure to operate the engine again for visual inspection of valve cover areas, using a small mirror and flashlighjt... another visual of the Tensioner area can be made by positioning the mirror beneath the right front valve cover... just to the rear of the air pump. By facing your flashlight into the mirror, the light will be reflected into the side engine area and another good visual of the tensioner area is possible after a drive and operation of thirty minutes. :thumbsup:

Hope this is of help,

Robert :thumbsup:
 

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Are you really worried about the Chain Guides and Timing Chain?
Hello,

I happen to be gathering info and parts for a guide rail R&R for my M119.982 (a '97 SL500), and I'm wondering if I should also be concerned about the tensioner. My experience with tensioners on previous vehicles is that they can just fracture during hard acceleration.

On these M119's (my tensioner is A1190501711), what is the tensioner failure mode? Is this a preventative maintenance R&R item? I have 171K miles, and I'm presuming that it's the original tensioner.

Thank you,
John
 

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1997 S600 (sold)
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Hello,

I happen to be gathering info and parts for a guide rail R&R for my M119.982 (a '97 SL500), and I'm wondering if I should also be concerned about the tensioner. My experience with tensioners on previous vehicles is that they can just fracture during hard acceleration.

On these M119's (my tensioner is A1190501711), what is the tensioner failure mode? Is this a preventative maintenance R&R item? I have 171K miles, and I'm presuming that it's the original tensioner.

Thank you,
John
John, I would send a PM to mercedex mechanix. This is an old thread. I don't know if these guys are reading the forum as much lately, but in my experience, they respond promptly to PM's.

Brett
 

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Yes you should be extremely concerned with the tensioner at 130k+

Especially if you drive hard
 

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John, I would send a PM to mercedex mechanix. This is an old thread.
Thank you, that's a good point!

Yes you should be extremely concerned with the tensioner at 130k+

Especially if you drive hard
R&Ring the tensioner was my inclination, but I've never read any threads about M119 tensioners suddenly going bad.... Do they just crack, or does the spring break, or does it no longer fill up with oil?

Currently, I have zero indications that it's bad; there's no clanking, rattling, etc.... I'm just used to replacing tensioners on other vehicles as a preventative maintenance item....
 

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nothing broken. finally!
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Thank you, that's a good point!



R&Ring the tensioner was my inclination, but I've never read any threads about M119 tensioners suddenly going bad.... Do they just crack, or does the spring break, or does it no longer fill up with oil?

Currently, I have zero indications that it's bad; there's no clanking, rattling, etc.... I'm just used to replacing tensioners on other vehicles as a preventative maintenance item....

They just go...

i have photos of the internals somewhere.


92k, it just went, snapped camshaft, seized left side of engine

catastrophic failure. rare but when it happens :eek:

mbusa quoted over 30000 for a replacement engine. haha!

Way over the head of several people with a few cases of beer so it was towed to a pro. Sourcing parts and all took 2 months. And then the head leaked oil like mad so they had to open it again to fix it. Luckily it was only a gasket.

Tensioner wears out and no longer keeps chain in place. So jain jumps teeth and slack just goes from there

subsequently said engine had failed oil tubes and chain guides, which is probably what stressed out the tensioner too much. actually it had no chain guides left.
 

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2012 E350 CGI Avant Garde Sport, 2011 E350 Avant Garde Cabriolet
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I have mine replaced at 100K. Chain, guides and tensioner.

Peace of mind? PRICELESS!
 
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