Timing Chain - To change or not (sorry!)

[Hibbo]

Hello to everyone, having just read the water pump thread I decided to ask this question here, rather than hijack that thread. Appologies to Malcolm for bringing this subject up!

Simple really - Should I change the timing chain on my 300D?

The car is 23 years old with 186k on the clock. It has no service history but from the overall condition of the car and the engine I make the assumption that it has been looked after and at least had regular oil changes. I have changed the oil once in my ownership and the old stuff appeared ok.

I think there are two distinct schools of thought on this one; some people say change it every xxx thousand miles as a matter of course (I have heard 180-200k talked about for the om617), where as other people say if it isn't rattling like hell then leave it well alone. Can you REALLY hear them when they are on their way out?

If I was to change it, should I replace the tensioner, tensioner rail and guides as well?

Are factor chains ok (GSF, Eurocarparts?), or for something so important should I buy from Merc. Or are they likely to have came from the same factory regardless of what is stamped on them?

I have also read of people measuring the stretch in the chain, is this a worthwhile exercise or not?

I realise that this is quite a subjective isssue and as such there is no definitive answer, but I would really like to hear peoples' views on this matter.

Thanks in advance!

 

[tom7035]

Personally, if it's not rattling I'd leave well alone.

 

[Ian B Walker]

Personally, if it's not rattling I'd leave well alone.

I would second that. If it is rattling then change chain, tensioner and guide rails too. False economy not to. As for chain suppliers, they are pretty much the same. I have used both Merc and GSF chains in the past with no noticable difference in quality.

 

[Ron Palfrey]

I agree. If it ain't broke don't fix it. Just keep changing the oil and filter regularly using good quality oil.

Ron

 

[television]

As the othe answers, leave it if it is not rattling at start up or idle. When they are bad you will know by the noise. If the time ever comes to change it, one always fits a new tensioner, as for the guides it depends on their condition, if they are badly groved, change them, if not leave them.
When they are worn or streched then yes the timing does go out. many people have a difficulty in stopping oil leaks after removeng the timing cover, but if no noise leave it alone. Hope this helps

malcolm

 

[42847]

timing chains

my 1984 380SL 138,000 miles is perfectly silent when idling or driving but when starting up it has a 2 second crowl approx every 3rd time of starting whats your advice? 22 stamps in the book but never had a chain yet

 

[television]

my 1984 380SL 138,000 miles is perfectly silent when idling or driving but when starting up it has a 2 second crowl approx every 3rd time of starting whats your advice? 22 stamps in the book but never had a chain yet

Though most of these engines have a one way ball valve in the feed to the tensioner, the oil can and does drain sometimes, it can take a few seconds to for the presure to build up. Many people just change the tensioner as they do wea, and loads of people will come on and tell you how to do that.

Malcolm

 

[Hibbo]

Thanks to everyone, I think that is pretty conclusive - I will leave it alone!

I think I'll change the oil again though soon.

Now to decide how to tackle the rust that's appearing, to cut and weld or to grind and fill... (standby for a new thread next week)

Thanks again, I really do appreciate everyones' advice.

 

[sankey]

The rust is a worce problem,the chain will go on forever.

 

[IAN MAC]

Cut and weld it, grind and fill and you'll be doing it again next year