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Hello fellow enthusiasts,

Doing some timing chain and guide rail/tensioner work on our 500SEL project car - and I'm trying to remove the gear off of the passenger (US) side lower cam. The gear appears to be held on with three Torx bolts, and those suckers are tight - I've already stripped the head of one of those, so I'll be having to cut that off and replace.

Anyone with experience have any idea if this is normal? If so, what have you done to get them off without killing the torx head?

Thanks as always!
~Bryan

p.s. the project is a really well cared for 500SEL that has been idle for 7 years. We've straightened out the fuel system, and now discovered that the cams have jumped teeth, either due to a failed tensioner or several (confirmed broken) guides. We're performing the leak down test today to get an idea if we have valve damage, so far boroscope does not indicate as such, although we know that will be inconclusive. Replacing the chain and guides will require removal of the cams, and that should also allow for a good time to do a compression check, when all valves are theoretically in their seats. Thanks!

Photo of the project below. It's actually my son's $1200 project (he's 16 and has the bug...) We are prepared to do an M119 swap if we have to, it's a good learning experience for him!
 

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Bryan,

Here is what I would do as my buddy just did the same thing to three spare engines for his 93 500SEL.

If your bolt is still there, leave it there. Read below..

A) I would check the timing, and remove the valve covers. Set the harmonic to 45degrees and see how far off you are. I know it jumped, but you really want to know how far you are by the alignment holes on the cam(not all holes are the same size. One is different from the rest) sprockets. You may have to manually turn the engine to get the CAM's to be timed-Remember turn it clockwise while you are facing the engine. See the restoreyour Mercedes videos on youtube:

https://www.youtube.com/results?search_query=m119+timing



B) You do not need to take the sprockets out, yet my buddy did not do that for his three engines. Just remove the CAM hold downs, but keep them in order how they came out.

C) you will also see how bad your chain got by all.... the scratch marks(or wear marks :( ) on the valve covers.

D) One replace all the guides except for one which is also the one with less wear from the top without taking the timing plate cover, but you need the special guide-extractor tool to remove the pins. Buy a premium gasket for the tensioner.

E) Mercedes requires a special chain tool which can be a pain to put the press-on keeper, but aftermarket their is a snap-on keeper that makes life so much easier...

F) If you want to remove the chain tensioner bits which they are all plastic except for one tensioner. Then you will need to lift the engine out. You should change the rubber boot around the oil pick-up-which is rubber, and not plastic as it will appear as plastic because it is so so hard...

Here are some threads


https://www.benzworld.org/forums/w140-s-class/1339994-s-klasse-119-97-engine-v8.html

https://www.benzworld.org/forums/w140-s-class/1361656-r-u-worried-about-your-t.html

https://www.benzworld.org/forums/w140-s-class/1474393-pulling-119-97112-early-90s-s.html

Hope it helps,

Martin
 

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Hi Martin,

Thanks so much for taking the time to reply - really appreciate it!

We did in fact check timing on the cams, and the holes in the sprockets are quite a bit off from aligning with the pins - much more than normal chain stretch I suspect.

We are planning to replace the chain, and all of the guides that can be reached with the front cover in place. I have reviewed Victor's videos (restoreyourmercedes - the 5 part series about timing chain work on an s500 M119) and he removed all of the cams with the sprockets on them, except for the passenger side lower - he mentioned in the video that one had to come off to slack the chain off of the rest of the sprockets.

But then it made me think - we are going to replace the chain anyway, so perhaps I could just split the chain at the master link (if the master link is visible at 45 degrees TDC) and sip tie it out of the way. Do you have any thoughts on this? Victor was changing the chain as well, and he still removed the one sprocket. I don't see any way to get the cams off of the chain without either breaking it, or removing one of the gears -

Do you have any thoughts on this? I'm going to go now and inspect and see if I can see the master link. I guess I could always split it with a dremel tool since we're going to replace it anyway. I'm asking all of this here because there's not a lot of chatter about the procedure in the forums. Thanks for those links, the one with the front cover removed seems to have a lot of good bits of info!

Thanks again!
~Bryan
 

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Ha!

Took a look at the valve covers. Boy did the cam chain sure have a fight with one of the valve covers! Yep, I suspect that the timing jumped... a LOT. See photo:
 

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Lots of discoveries this morning as we probe deeper:

1) One of the cams the "hole" in the cam sprocket was almost 90 degrees off from the location of the pin. ooofff...

2) The "wear" on the valve cover (drivers side US) is severe- it had been wearing for a long time (see pic previous post.)

3) We had the crank positioned at the 45 deg TDC makr. We tried to rotate it around to see if we could see any kind of cam chain master link anywhere, and after about 40 degrees-ish of rotation, it became VERY hard to move by hand. Considering how far off the cams are, could this possibly be a valve saying "hello" to the top of a piston? The engine did try in the past to sputter and run, but perhaps valve <-> piston interference is a bit much to overcome by hand.

We sure would like to do a leakdown test, but it's seeming more and more certain that we have valve<->piston interference - and we may just start shopping for a used M119 - probably the least expensive route to go. This 500SEL is really really clean given it's age, so definitely worth the time investment.

Thanks in advance for your help!
~Bryan
 

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Hi Martin,

Thanks so much for taking the time to reply - really appreciate it!

We did in fact check timing on the cams, and the holes in the sprockets are quite a bit off from aligning with the pins - much more than normal chain stretch I suspect.

We are planning to replace the chain, and all of the guides that can be reached with the front cover in place. I have reviewed Victor's videos (restoreyourmercedes - the 5 part series about timing chain work on an s500 M119) and he removed all of the cams with the sprockets on them, except for the passenger side lower - he mentioned in the video that one had to come off to slack the chain off of the rest of the sprockets.

But then it made me think - we are going to replace the chain anyway, so perhaps I could just split the chain at the master link (if the master link is visible at 45 degrees TDC) and sip tie it out of the way. Do you have any thoughts on this? Victor was changing the chain as well, and he still removed the one sprocket. I don't see any way to get the cams off of the chain without either breaking it, or removing one of the gears -

Do you have any thoughts on this? I'm going to go now and inspect and see if I can see the master link. I guess I could always split it with a dremel tool since we're going to replace it anyway. I'm asking all of this here because there's not a lot of chatter about the procedure in the forums. Thanks for those links, the one with the front cover removed seems to have a lot of good bits of info!

Thanks again!
~Bryan
Bryan,

When you look up the Mercedes chain and "keeper" it is different from what the W124 E420/E500 use yet it is the same chain with a "Real" keeper not something you Dremil-off. I would remove the chain once your crank is at 45, and you loosen the tensioner. Have the chain-guide tool to extract the pins to the lower guides, but remember the lower"drivers guide" (I think that is the one) cannot come out from the sprocket openings, yet to get that guide out the work went double as you need to take brackets, harmonic balancer, chain cover, lower oil pan, and accessories - much more work.

You need to search the sections of W124/W140/R129/E500 board( lots of hard-core DIY there https://www.500eboard.com/forums/forum.php? ) as these had M119 engines, and the process is really the same for distributor and non distributor engines.

Remember to change the oiler o-rings on your metal oilers since the CAMs are coming out if you have plastic ones find the metal oilers ones on ebay

HOW-TO: Replacing M119 camshaft oiler tubes

Lots of discoveries this morning as we probe deeper:

1) One of the cams the "hole" in the cam sprocket was almost 90 degrees off from the location of the pin. ooofff...

2) The "wear" on the valve cover (drivers side US) is severe- it had been wearing for a long time (see pic previous post.)

3) We had the crank positioned at the 45 deg TDC makr. We tried to rotate it around to see if we could see any kind of cam chain master link anywhere, and after about 40 degrees-ish of rotation, it became VERY hard to move by hand. Considering how far off the cams are, could this possibly be a valve saying "hello" to the top of a piston? The engine did try in the past to sputter and run, but perhaps valve <-> piston interference is a bit much to overcome by hand.

We sure would like to do a leakdown test, but it's seeming more and more certain that we have valve<->piston interference - and we may just start shopping for a used M119 - probably the least expensive route to go. This 500SEL is really really clean given it's age, so definitely worth the time investment.

Thanks in advance for your help!
~Bryan
You are going to have to take the gamble, and install the chain plus tensioners to find out if the engine is okay. Go through your test, yet you will really know with a compression test too.

It is not worth the expense or trouble to go through head/valve testing as nearly all the W140's in the junk yard have no engine problems other than they too need new chains. My buddy got his engines when the junk yard had half-off days, so he paid like right at $100 to $120 on those days. Just pull the valve covers check the timing, and check how clean the engines are, and the rest is busy work. Remember you can use a upto a 95, but the accessory brackets are different as the 400SEL's/500SEL's have mechanical adjustment for the belt, and have one or two more groves for the belt.

San Jose Pick n Pull had a clean 92 500SEL like six weeks back, and a 92 SL500 in Newark.. Check the specials. They will have one near Christmas:

Pick-n-Pull » Events & Specials

Pricing:

Pick-n-Pull » Part Pricing @ Pick-n-Pull - San Jose North

Here is the search links...


https://row52.com/Search/?YMMorVin=YMM&Year=1992-1995&V1=&V2=&V3=&V4=&V5=&V6=&V7=&V8=&V9=&V10=&V11=&V12=&V13=&V14=&V15=&V16=&V17=&ZipCode=&Page=1&ModelId=3626&MakeId=182&LocationId=&IsVin=false&Distance=50

https://row52.com/Search/?YMMorVin=YMM&Year=1990-1995&V1=&V2=&V3=&V4=&V5=&V6=&V7=&V8=&V9=&V10=&V11=&V12=&V13=&V14=&V15=&V16=&V17=&ZipCode=&Page=1&ModelId=3628&MakeId=182&LocationId=&IsVin=false&Distance=50

Messy soupy job, but worth it - better than car payments..

Martin
 

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Abolutlely right Martin, better than car payments!
I'm just excited that my 16 year old is interested in such a safe car! Of course, he is a teen, he wants to port and polish the heads at some point haha!

Thanks for the tips! I was able to finally get the stripped-head Cam sprocket torx pulled out (turned it into a slotted head with the help of Mr Dremel) and now the chain is able to be removed off the other cams, so we'll remove those and set to work on replacing the guides.

Finally read the Alldata text carefully. I was searching for some kind of "master link" and there apparently is not a (visible) one. Alldata (Mercedes) says:

- Grind chain pin of timing chain (4) between inlet and exhaust camshaft sprockets open (Fig. C),
- Pry plate (8) of timing chain (4) off with a screwdriver (Fig. D).
- Push out ground-open double link

So we're off to the races. While we have the cam gears out of the way to get to the rails/guides, we'll do a quick leakdown test to see if there's any indication of valve bent-ness - and if not, then we proceed and hope for the best!

Funny you should mention that Pick and Pukk '92 - that's on our radar in the next few days to go up and grab a few parts - including the cam oilers - if they've not been taken yet - we have a '95 e420 that has the plastic oilers, and at least one is ticking.

Thanks again for taking the time wor offer your help!
~Bryan
 

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Abolutlely right Martin, better than car payments!
I'm just excited that my 16 year old is interested in such a safe car! Of course, he is a teen, he wants to port and polish the heads at some point haha!
Ohhh yea, Ferrari and Indy 500 dreams on Homeless wages... Been there done that....

I took my fathers Chevy Nova appart, and could not put it back together, so it had to be junked...:eek: :help: :crybaby2:


Funny you should mention that Pick and Pukk '92 - that's on our radar in the next few days to go up and grab a few parts - including the cam oilers - if they've not been taken yet - we have a '95 e420 that has the plastic oilers, and at least one is ticking.
Ahhh a little Birdy :nerd has told me that(PnP) Pick-N-Pull(at lease in Sacramento, or Northern California) is having a 50% off or something real close to it this weekend, yet it is not on the events page, but it is probably posted there at each PnP, or everyone got a notification by email from Row52.com...

Glad to of helped. I need to change my chain soon on my V8..

Best of luck,

Martin
 
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