Timing chain replacement - when to do it - Benzworld.org

graymarket500SEL · 11-20-2002, 01:17 PM

I am getting my timing chain replaced (along with the guides and what not)...
the shop is charging me $1,100 for parts+labor on my 83 500SEL. Does that sound reasonable?

When I asked what condition the chain was in my car they said that it had 15 degrees of play. I was also told that 10-12 degrees was when the chain was deemed to need to be replaced... I hadn't heard that before.

Just asking for some feedback.

What else should I get done? Water pump?

Todd · 11-20-2002, 01:42 PM

hmmmm. I thought anything over 4 or 5 degrees play warranted a timimg chain replacement. Mercedes service schedule recommends to have the chains on V8's done every 100K miles. Alot depends tho on how the engine has been maintained. Frequency of oil changes etc. They key element is the condition of the upper guide rails. They get old and brittle, chain starts slapping around and either breaks up the guides or the chain itself goes south. Either way it's not a pretty picture. [:0]

I would presume for that much cash, they are doing the lower guides too? How many miles on the car? I'm not sure how similar the job is for your car compared to mine ( 1990 420SEL) but I was quoted $650-700 plus tax for new chain, upper guides only, and tensioner. I was told the lower guides very rarely need to be changed because they are constantly bathed in oil. If that estimate doesn't include the lower guides, I would definitely ask around and get a few other estimates.

Litton · 11-20-2002, 02:01 PM

After reading some of the horror stories regarding the 420 and their timming chains, I had my mech check mine yesterday. He said mine had been replaced (time unkown) but that I have 8 degrees of play/stretch which is OK and that tensioner and stuff was fine. Car now has 170,000 miles so I think I will get it checked again at 200,000 and see what happens. He did not mention what the max degrees that are acceptable.

Todd · 11-20-2002, 02:20 PM

Yeah, don't take my word for anything regarding the "degree" stuff. I'm not a mechanic but was just trying to remember off the top of my head, what they told me when I had mine checked at 116K.

graymarket500SEL · 11-20-2002, 03:27 PM

I purchased my 83 gray market 500sel a few months ago with 163,000 miles for about $2,500. I've put on 10,000 miles since. I don't know when the last time the timing chain was replaced if ever, so I'm having it done for my peace of mind.

yes I'm having the lower guides replaced as part of the timing chain job. I wonder if I ought to get the water pump and thermostat done too...

golfkaki · 11-20-2002, 07:29 PM

Have also the valves and pistons checked.

Englevakten · 11-21-2002, 02:33 AM

woops...

i had my chain done 6.000km agoo, (3750 miles)... but no one in the southern of norway had the guides or tentioner on stock, they had to be ordered from germany. this usually takes only three days, but all the stores in and around oslo were changing suplier, so they couldn't promise the guides in less then two weeks. so, unless i wantet to pay 3 times the amount for a speed delivery, i had to either wait, or get the chain done without having the other parts replaced.

i went for the last option. the guy at the repair shop said the guides looked fine... don't know how much one can trust someones judgement but i saw myself that they weren't that bad. at the worst the guides didn't even have a quarter of a millimeter crease. (don't know about the brittle part)

so, anyways... it's been fine. but yesterday i turned the key to start, but held it just a tad to short, so the car ended up not starting... instead i heard a scraping noise from the chain (i now know what it sounds like) rubbing twords something, most likeley the plastic guides.

my guess... the tentioner's not doing it's job in hole, and that the chain now has a little more slack doing it's thing and is rubbing off on the guides...

anyone else with a different opinion? could use the help. wouldn't want to use more money unless necesary, but would defeneatly not want to screw my engine up...

any one's $0.02?
Engle

golfkaki · 11-21-2002, 08:15 AM

Dear Engle,

As you know, I had to replace my engine.
Engine and new parts will cost me three grants.

The chain and guides were not at fault, but rather a valve perforating a piston, that led to a guide being broken.

Only advise I can give you is not to try to start your engine and make things worse.
Have a guy that knows MB take a look at it.

cheers,
charles

Jim Austin · 11-22-2002, 02:42 PM

I had my timing chain replaced at 170K miles. Now, at 205K, it just jumped time and broke the valve cover. I may be looking at $4K+ to fix it. Don't do the job halfway. Put in the new rails, tensioner and anything else in there with the chain.

golfkaki · 11-22-2002, 09:56 PM

Academic question:
was it the timing chain, the valve, or else?

PS: Engle! how's your car?
Good, or not so good news?