[sarg0406]

Quick question because I am finding different answers to this question on this forum. If I’m going to do timing chain, gears and guides on a 99 SL500 can I do it without removing the engine and how long should it take? Thanks.

 

[RESTO SL]

I can do it in three to four hours. But what makes you think the chain, gears and guides need replacing?

 

[sarg0406]

I can do it in three to four hours. But what makes you think the chain, gears and guides need replacing?

Thanks for the response Resto SL,
The car has 97000 miles on it and is 24 years old, and from what I have read, the timing chain guides tend to get brittle and break, so I figured if I was doing timing chain, guides and tensioner that I may as well do the gears as well since I am in there. Do you recommend otherwise?

 

[RESTO SL]

You have a low miles M113. I don't know what your symptoms are, but don't need a new chain and guides.

 

[Ken S]

On Mercedes V8's of the 70s-80s, age and brittleness of the guides is a significant issue regarding potential catastophic engine failure. For many fine collectable Mercedes, the timing chain guides had a dissapointing lifespan.

Since the 90's, this is less of an issue with the M119 V8. There are some simple guides that are easy to replace at the top of the cam gears on M119 (those ones are common to replace... so that may be what you are reading about on R129s -edit).

Tensioners are also more reliable since the earlier motors. I believe the M113 is similar in this regard. Mercedes (and others) did learn some lessons along the way. Is there a particular issue that has you concerned about your low milage M113?

 

[sarg0406]

On Mercedes V8's of the 70s-80s, age and brittleness of the guides is a significant issue regarding potential catastophic engine failure. For many fine collectable Mercedes, the timing chain guides had a dissapointing lifespan.

Since the 90's, this is less of an issue with the M119 V8. There are some simple guides that are easy to replace at the top of the cam gears on M119 (those ones are common to replace... so that may be what you are reading about on R129s -edit).

Tensioners are also more reliable since the earlier motors. I believe the M113 is similar in this regard. Mercedes (and others) did learn some lessons along the way. Is there a particular issue that has you concerned about your low milage M113?

I have a loud “clicking” and cannot tell where it’s coming from. I have used the old “screwdriver to the ear” trick on valve covers, EGR valve, air pump, pretty much everything and cannot find it, so thought it might be timing chain guides. And since I had heard that the guides broke over time that I’d just go ahead and replace them and all related items. Any idea on my ticking? Almost wondering if it could be an exhaust manifold gasket like the old Chevy 350’s used to do.

 

[RESTO SL]

A loose timing chain is more of a rattle than a click. I'd recommend finding a shop that can diagnose what you're hearing.

 

[sarg0406]

A loose timing chain is more of a rattle than a click. I'd recommend finding a shop that can diagnose what you're hearing.

I was an ASE Master tech when I got out of the automotive industry in the late 90’s. I’m more than capable of doing it myself, however have no experience with Mercedes, so was trying to gleen some knowledge and experience from this forum. But it doesn’t seem to be working. Thanks.

 

[Ken S]

Don't give up on us.
We just need more of description than youve given us 2 hours ago . Perhaps post a brief video with sound.
Good job trying the screwdriver as a listening stick, but an inexpensive mechanics stethoscope should be able to isolate the sound if it is in the valve train.
Also, check the simple stuff.
Fan turning freely with no contact to anything with engine off?
Fan clutch feel and sound OK with engine off? no excessive play?
Serpentine belt not cracked or frayed with stringy bits flapping their way around?

 

[RESTO SL]

Now that think about it...you should definitely replace all timing components.

 

[carltwo]

Sarg0406,
Ken S and RESTRO SL are trying to help and the rails and tensioners don't have problems with your mileage. When my car reached 250,000 miles I heard a rattle at startup and then it would quickly disappear. That's a sign of broken rails or tensioner or chain problems. All my rails were brittle and parts up the rails were missing. At that point I replaced the chain, tensioner and rails. I believe your ticking noise is at the top.

 

[hattie]

Does it go away when you rev it up a bit could it be a lifter not pumping up? I have never heard of m113’s having timing chain issues. Or many issues they are pretty reliable.

 

[quincy k]

Sarg0406,
Ken S and RESTRO SL are trying to help and the rails and tensioners don't have problems with your mileage. When my car reached 250,000 miles I heard a rattle at startup and then it would quickly disappear. That's a sign of broken rails or tensioner or chain problems. All my rails were brittle and parts up the rails were missing. At that point I replaced the chain, tensioner and rails. I believe your ticking noise is at the top.

could that also be a lifter problem when its only at start-up?

 

[Ken S]

I believe your ticking noise is at the top.

could that also be a lifter problem when its only at start-up?

I think that is what Carl was refering to (and Hattie).

Another few questions for sarg0406...
Did this "clicking" sound start suddenly or evolve over time?
What oil are you using?
How is the oil pressure? Hot and cold at idle?
Any idea how frequent the oil changes have been on the car over its life? (When you inspect the under the oil filler cap, does it look relatively clean (with a brownish haze) or is the inside of the valve cover and valve train covered in dark crud?)