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1988 560SL - 120k miles
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6 Posts
Discussion Starter #1
Hi,

New to this (great) forum as I just bought a very fine example (at least on the outside) of an 1988 560SL. The electrics all work, the body is in very good condition but I have NO maintenance records for it. The engine has 116.000 miles on it and seems to be running fine. I had the following done:
- oil-change and transmission fluid change
- Spark plug (incl cables) change
- Air filter change

I also had them check on the following:
- Engine and transmission mounts
- Flexdiscs
- Oil leaks
- Brakes
- Subframe mounts
- steering parts
- Suspension

Interestingly enough everything came back as 'just fine' - but the one thing I really wanted to check because of a possibility of immediate complete engine destruction was the timing chain and tensioner - but the shop said that just ot check this would be 25 labor hours in order to get to the timing chain... is this correct or do they not know what they are talking about?
I'd rather play safe and have it changed, but am not prepared to pay $3500 dollars for it not knowing if is it in good shape or maybe has already been done by the previous owner

What are your thoughts? is 116k a high enough milage to warrant this? Should it be cheaper?

Thanks
Marco
 

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Premium Member
2010 Mercury Milan Hybrid, 1993 BMW 325i convertible
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6,077 Posts
the shop said that just ot check this would be 25 labor hours in order to get to the timing chain... is this correct or do they not know what they are talking about?
They don't know what they're talking about. Simplest method is to turn the engine until it's at TDC, then take off the valve covers and look at the timing marks. If they're on, you have a new chain. If either/both of them are off, you have a stretched chain. How much off tells you how much stretch.
 

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1979 280SL, 1984 280SL
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5,641 Posts
It's not even so much that your chain can stretch, it's more that the nylon tensioners get old and brittle. A piece can easily break off, get between a sprocket and the chain and ruin your day. Your chain may check spot on, and you could still have this failure. Have a different shop, one that is familiar with this engine series, take the cam covers off and check. Timing chain and tensioners should cost around $1k, give or take a bit.
 

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1988 560SL - 120k miles
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6 Posts
Discussion Starter #4
Thanks! That's what I thought - if they are already checking it, wouldn't it make sense to then also replace it (at least the tensioner)?
 

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1979 280SL, 1984 280SL
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5,641 Posts
Well, yes and no. You don't have any service records, yet many of the other components you had looked at checked out ok. That means one of two things: The shop didn't know what they were talking about, or some of those bits have been maintained. The front suspension in a 107 will almost certainley need some real attention by the time it is 20 years old, with 100k miles. If it has been maintained, it is possible your tensioners, etc may have been replaced. Old, heat cycled components will be dark reddish brown, whereas some of the new tensioners are white ( I think there is a black one in the mix as well).

Just taking the cam covers off doesn't mean "while your in there." Changing the tensioners is a bit of a pain, but do have them checked out by someone who knows. 116k is borrowed time for the originals. Look thru the search function here- there's a lot of info on the chains and tensioners on these cars.
 

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Premium Member
89 R107, 05 CDI
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2,536 Posts
chain guides

Hey marcoma,

Welcome and enjoy the forum... just for clarity's sake, when Chief says tensioners and speaks of the colour changing to a dark red colour, he is actually referring to the chain guides. He's right, there is a ton of info on the forum about them. There are tensioner(s) too.

It is a good idea to deal with them now. It's not just a mileage thing, it's an age thing. My little 1989 beastie has less than 24k miles and I worry every time I drive it, it's 21 years old. Next spring first thing for me: timing chain, those guides and tensioner(s), and then flex discs.

We had a new poster on here about four or five months ago who had just bought a 107 like yours. He had bought it for his wife as a surprise gift. She was ecstatic! They had had it for a short time, like less than two weeks, the OP backed it out of the garage heard a strange sound and then a horrible rattling crashing sound... guess what the assessment was... timing chain.

A sad tale for sure...
 

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1979 280SL, 1984 280SL
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5,641 Posts
Thanks for the catch on nomenclature! So while they are doing your nylon guides, also replace the hydraulic tensioner!
 

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R/C107 Moderator
1986 560SL: '84 500SL: '84 280SL 5 speed: other 107s
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32,003 Posts
Go to the user cp and fill in your profile. There may be someone in your area that can suggest a good independent shop. There is also a link to parts suppliers and recommended repair shops in the encyclopedia above.
25 hours to get to the timing chain just to check it? Must have misread the 2.5 hours in the book. Even 2.5 hours is a stretch to pull the valve covers, check the chain, guides, tensioner and put it back together.
 

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Registered
1988 560SL - 120k miles
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6 Posts
Discussion Starter #9
this forum is just excellent! - Thanks again... I will get the car to another (specialised) Mercedes shop to have this done...
So I guess once that is done I should be reasonably up to speed on the maintenance... unless you can think of other things that should be on the preventative list. The only other thing I worry a little about is the transmission. Got the fluid changed - is there anything else I should take care of? I'm a big proponent on getting things done before they break... Had an Alfa Spider before and I'm already excited about the fact that I even can do proactive things... never got to do that on the Spider as I was in constant catch-up mode even after spending 2 years in a garage (that is being worked on, not stored) :) But that's a different story...

Thanks again guys...
 

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2008 E320 Bluetec, 1988 560SL totalled unto death). 1997 Dodge Ram 1500, 1983 300CD
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1,320 Posts
chain tensioner service

The mechanic may have misunderstood what you wanted. Replacing the upper chain rails and the plastic slipper on the tensioner as well as the chain is an approximate $800 to $1000 job. If you want the lower chain rail also checked or replaced it could easily be the figure he quoted. Access to the lower tensioner requires removal of the radiator and the front engine cover, a big job indeed. That lower rail seldom fails and most do not replace it.

While the cam covers are off, replace the cam oiler fittings unless they are brand new. They are plastic also and prone to cracking from heat cycling. It is an easy job and can be done yourself as can the chain and component inspection. Have new cam cover gaskets on hand. If the mechanic does it, should add no more than one hour to the job.
 

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1988 560SL (California Model)
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5,087 Posts
I recently bought a "88 560SL with 94,000 miles. For peace of mind the first thing I did was replace the timing chain, upper guides and tensioner. Fortunely for me a good friend having done this before did the lion's share of the work. Here's what we found.



One of the guides had broken in half and the broken piece was laying diagonally (notice the wear marks). The color difference is due to the lighting. I was lucky and if this isn't evidence of the need of a through inspection...what is? We also replaced the water pump since the old one had to come off anyway along with the cam oilers.
 

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1988 560SL - 120k miles
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6 Posts
Discussion Starter #13
Wow - couldn't somehow see the picture you posted but the story is scary enough - I'll have it done on friday by a place that deals exclusively with Mercedes (and mostly older ones apparently), so they should know their stuff... got quoted around 800 for a chain replacement incl. the tensioners and guards so that sounds a lot more reasonable - Plus they sounded carefully optimistic in getting it done within the day...
Thanks again for all your help - I will have the oiler fittings changed as well plus probably the waterpump...
 

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Premium Member
89 R107, 05 CDI
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2,536 Posts
I recently bought a "88 560SL with 94,000 miles. For peace of mind the first thing I did was replace the timing chain, upper guides and tensioner. Fortunely for me a good friend having done this before did the lion's share of the work. Here's what we found.



One of the guides had broken in half and the broken piece was laying diagonally (notice the wear marks). The color difference is due to the lighting. I was lucky and if this isn't evidence of the need of a through inspection...what is? We also replaced the water pump since the old one had to come off anyway along with the cam oilers.
Yikes! What a tale... could you try to post that picture again?

Good for you for taking care of that, very good.
 

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Premium Member
1972 280CE
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4,204 Posts
I replaced the chain, tensioner and rails on my 500SL, 500SLC, 560SEC and 6.9 late last year.

On my 500SLC, 560SEC and 6.9, I found guide rails that were partially broken that i had to fish out with a long pair of pliers. On the 500SL, the car looked like it had recently had head work but one of the cam towers was broken and one of the camshaft bearings was extremely worn.

As a matter of course, you should check under the valve covers because there is no telling what you would find.
 

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Premium Member
89 R107, 05 CDI
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2,536 Posts
Question, I was speaking with a forum member last week, and he said that it isn't really necessary to change the guide rail that is at the bottom of the engine... Does anybody know why that is the case?
 

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Registered
1979 280SL, 1984 280SL
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5,641 Posts
My Indie told me the same thing. It's probably a variety of reasons. The ones that come to mind are these: It's a pain in the neck. The front cover has to come off- lots of labor. It's not a common failure mode. This may be due to an inherent condition such as the nylon component doesn't usually break, or if it does, it falls harmlessly out of the way. This is only speculation. I'm sure someone will weigh in that knows more than me.
 
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