HEllo guys.93000 miles and getting ready to do the timing chain..sould i change tensioners and guides? does this mean taking off the front of the engine and if this is the case can I get a chain that is already continous and install it in one piece. I have read the searches and the argueing has clouded the technical info. Also tools and proceedure would be helpful. Thanks
Brian

Arguing over timing chains...Never !
Seriously, are you experiencing problems? I am at 105K on my 400E and my tech has specifically stated that a chain change now is not required. I would be interested in what you have heard.

As far as rails...If you are gonna do "it"..do it all. Tensioner, rails, chain....get it over with!

I understand that the chain on the 119 is the most durable part of the system. The tensioner and upper rails tend be be more fragile. I'd watch them more closely and if you are going to replace the chain, take care of all the support parts at the same time...

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Jeff
'87 300E
'92 400E
'06 ML350

I'm in the same boat -- 108 kmi, and my tech says leave it alone. I am interested in what's involved, though, in the event that it needs to be done; I've heard it's a pretty big job on our 119 engines.

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Steve
'93 400E

note the word 'required' vs. 'recommended' (...I imagine when there's a failure...the word 'required' will come up with an exclamation point)

...you may wish to consider and note your appetite for risk ..are you risk adverse on this matter?

..if so, you may wish to proceed with a maintence service/review in this area...ie having a tech look at the plastic rails and/or show you them & have the chain measured for stretch (compare to range)...that info will offer better data to decide on proceding with these items

hope this helps
-fad

thanks for the input. Do you know the proceedure for inspecting the rails..I have done the search and found plenty of discussions on the subject but no real objective technical data. Thanks

I really disagree about the interval about 150K being the time for the timing chain change on the 119. The problem is that the chain is NOT the problem. It is the upper guides. My 119 motor (119.960) was only 5 degrees BTDC off before the change, yet both upper rails were disintegrated to hell, the chain under the left intake bank was riding on the slide pin! Therefore, engine timing alone can't tell one squat on the DOHC motors in my opinion.

I would pull valve covers and examine the upper slide rails. 100K-120K is the time for the chain, rails, and tensioner. Note the post on using only a factory tensioner for the job. BTW, the new tensioners no longer have an oil check feed on it. It's completely blocked off from the factory! Therefore, the tensioner is always under tension and thus, so is the slide rail and the chain. Great idea. Too bad it took 5 revisions before they got it right. Insist on new stock chain and tensioner when replacing them. The latest chain has a different lock on it as well.

Satish
1989 560SEC with engine 119.960 5.0L/32V DOHC

do you guys think it is smart priming these high tech engines. I remember reading on this board that 97+ M119 and M104 dont need priming.

They don't need priming. We actually looking into this issue. All you MIGHT save is MAYBE the block itself but those blocks are good for 400,000-550,000 miles anyhow. Considering the cost of the equipment, installation, and possible problems if they fail, I wouldn't bother.

Satish