M119 Timing Chain Tensioner

[Pdmotors]

Hi guys and gals, if you are out there. Can anyone give me a heads up on how easy it is to change the timing chain tensioner on the M119 engine. I had my W124 500e engine rebuilt by a well respected Classic Mercedes engine rebuilder in the Frankfurt area. My engine originally had something like 280.000 kilometres on it when it went in for it’s rebuild. It still ran like a train, but had a head gasket leak on one bank, and a rattling timing chain on start up from cold.
Looking at the engine rebuild sheet, for some reason the oil pump had not been changed. After checking online when I got the car back to Spain, I realised the pump commanded a 600 plus Euros asking price. They guys told me it still made good oil pressure, so it was deemed not a requirement to change it. After doing just under 2000 kilometres to get the car home, being driven very slowly. I have not driven it since....that was six years ago after I realised the timing chain still rattled.
The guides had been changed during the rebuild, so I figured the oil in the head was leaking back into the sump over a period of time. So I replaced the check valve in the filter housing, this made no difference. I have a new check valve for the oil pump as I suppose this could be worn at the mating face allowing the oil between the the pump and filter to back flow into the sump when static. Having said that, I am now suspecting the actual timing chain tensioner had not been replaced and may not be sealing correctly. I say that because once the engine is warmed up, if I rev the engine, I can hear a little timing chain slap....or at least that’s what it sounds like. I have found the tensioner online at a very good price.....but how easy is it to change.
If that fails, I will try the pump. Any info would be much appreciated.

 

[Pdmotors]

I should add that the chain and guides had been replaced. It’s a 1990 model and runs on 10-60 weight full synthetic oil.

 

[gsxr]

Replacing the tensioner is straightforward, but tedious. You must remove the passenger valve cover, set crank to 45° BTDC, pin the camshafts, then replace the tensioner, and re-assemble.

Link to factory procedure:

https://freescruz.com/.priv/W124/w124CD1/Program/Engine/119/05-3100.pdf

If the rattle at cold start remains, you may need the updated / later intake cam adjuster springs, as noted here... the 3rd version should be used for repairs:

https://freescruz.com/.priv/W124/w124CD1/Program/Engine/119/05-2170.pdf

If oil pressure is normal (above 0.5 bar at hot idle and 3 bar above ~1500rpm hot), the oil pump is fine.


Is this the startup rattle sound?

 

[Pdmotors]

Thanks Dave for the info, much appreciated. It all sounds and looks straight forward, and yes, that’s the exact sound I get.

 

[Pdmotors]

Just as a side note, after one day of shutdown, I only get a small duration rattle with the timing chain on startup. If I leave the engine for any longer, the rattle sounds very dramatic until the oil pressure rises. So what I have to do is bump the motor over on the starter with very short burst of cranking until I see oil pressure, then I can let the engine catch and allow it to idle. This scenario is what lead me to believe that some how the oil was back flowing back into the sump over a period of time. Which is why I initially replaced the check valve in the filter housing, but if the oil line from the pump to the filter housing is emptying, then again, this could be the lack of oil pressure on startup. I also remember that the oil level on my dipstick also rises over a period of time, which for sure means the oil is actually back flowing.
In the mean time, I will order up a Tensioner for my motor and see what the result will be. I may have to leave this project till after August as my current garage may be lost any time soon and I don’t want to start stripping the motor and then have to try and move the car.
I will let you guys know how it all works out. Once again, thanks for the info.

 

[gsxr]

The rattle sound in the video is from the cam adjusters. Messing with oil type, oil pump, etc won't make any difference for the issue where the noise occurs for a few seconds only, i.e. after 1 day of shutdown. I believe the fix will be installing the "3rd version" spring in the adjuster mechanism, assuming you already have the late style drainback valve in the filter housing, which it sounds like you do.

If the filter housing really is emptying, and sump level rising, something may be fishy with the filter housing itself. Might not hurt to remove the filter and verify it is fully intact and undamaged?

The noise with the engine running is of more concern, that should be investigated and eliminated.

 

[Pdmotors]

Thanks Dave.

 

[Sam SL]

Replacing the tensioner is straightforward, but tedious. You must remove the passenger valve cover, set crank to 45° BTDC, pin the camshafts, then replace the tensioner, and re-assemble.

Link to factory procedure:
https://freescruz.com/.priv/W124/w124CD1/Program/Engine/119/05-3100.pdf
If the rattle at cold start remains, you may need the updated / later intake cam adjuster springs, as noted here... the 3rd version should be used for repairs:
https://freescruz.com/.priv/W124/w124CD1/Program/Engine/119/05-2170.pdf

The part number for my cam adjuster springs, item #54, is 119 993 02 05. Do you have the part # for the 3rd version?

 

[gsxr]

The part number for my cam adjuster springs, item #54, is 119 993 02 05. Do you have the part # for the 3rd version?

The spring is NLA, but I think any donor from 1994-up should have the latest 3.0mm wire diameter spring. I'd try to buy used cam adjusters (eBay?) to harvest the spring, if you don't have a local junkyard to raid.

Edit - see post below.

 

[Sam SL]

Interesting because the version for my 92 is still available, shows 56 still available. I'm debating if it's worth just getting a couple of those. Chances are the ones in my engine are still the original ones.

 

[gsxr]

AFAIK the latest version for .97x engines is p/n A1199930205 and MB Classic does show it available! Either my memory is off, or the p/n came back from the dead... under $50 each from discount dealers:

Spring 119-993-02-05 | MB of Covington

Spring 119-993-02-05

parts.mbofcovington.com

Mercedes-Benz Classic Parts Search.

Browse through the Mercedes-Benz Classic Parts Search to see the availability of parts, promotional and newly manufactured parts and order them online (only in Germany).

partssearch.mercedes-benz-classic.com

 

[Sam SL]

The number you show is the number I quoted. Therefore if I use that number I should get the latest version spring which is 3mm, yes?

 

[gsxr]

The number you show is the number I quoted. Therefore if I use that number I should get the latest version spring which is 3mm, yes?

Yes, that is correct! I'm going to order a pair of these as well for one of my 1992 engines...

 

[Sam SL]

AFAIK the latest version for .97x engines is p/n A1199930205

So I assume this part number supersedes 2 earlier numbers, being that it's the latest version?

 

[gsxr]

So I assume this part number supersedes 2 earlier numbers, being that it's the latest version?

Yes, that is my understanding.

 

[Sam SL]

Yes, that is my understanding.

Dave, do I replace 2 springs to possibly address the problem discussed in this thread?

 

[gsxr]

Dave, do I replace 2 springs to possibly address the problem discussed in this thread?

If it's the cold start rattle noise, and the oil filter has the late-style drainback valve, then yes the late springs may help cure this. Should only apply to cars though mid-1993 USA model year (approx Dec-1992 production) if the FSM info is accurate.

If there's a different noise, with the engine warm, I don't think changing the springs will help.

 

[Sam SL]

If it's the cold start rattle noise, and the oil filter has the late-style drainback valve, then yes the late springs may help cure this. Should only apply to cars though mid-1993 USA model year (approx Dec-1992 production) if the FSM info is accurate.

If there's a different noise, with the engine warm, I don't think changing the springs will help.

Yes, noise only at cold start and more pronounced when car sits for extended periods of time. Build date of my car is April 1992. As for the late-style drainback valve, what is that part number?

 

[gsxr]

As for the late-style drainback valve, what is that part number?

Should be 119-184-01-30 and you have to remove the filter housing to R&R... messy job.

 

[Sam SL]

The rattle sound in the video is from the cam adjusters. Messing with oil type, oil pump, etc won't make any difference for the issue where the noise occurs for a few seconds only, i.e. after 1 day of shutdown. I believe the fix will be installing the "3rd version" spring in the adjuster mechanism

Dave is a special tool (pictured) required to install the spring in the adjuster mechanism? Or is the special not related to what we are talking about.

 

[gsxr]

Dave is a special tool (pictured) required to install the spring in the adjuster mechanism? Or is the special not related to what we are talking about.

You have to disassemble the adjuster mechanism to replace the spring. The tool is an assembly aid. People have re-assembled the adjuster without the special tool but from what I've read, it's a RPITA. I'd seriously consider buying the tool if it's in your budget, and/or may use it in the future. Alternately you could re-sell the tool when you're done to recoup some of the cost.

 

[Sam SL]

I wonder if anyone on this board has the tool.

 

[R129 UK]

Replacing the tensioner is straightforward, but tedious.

I replaced mine yesterday, I found this trick which makes it quite a bit easier as you need to overcome the resistance when positioning and pushing it into place to get the fixings in.

First, I found it very easy to work from underneath on my 119.982 because there is a nice gap above the altenator to get access.

Second, I used a slightly longer M8 bolt and washer from the power steering pump (the right in the photo below) temporarily to get the thread started and then did that right up which pulled the tensioner in just far enough to fit the nut and washer which I then did right up. I then removed the longer bolt and replaced it with the correct one (on the left below):