84 300sd timing chain - PeachParts Mercedes-Benz Forum

Sash · #1 01-01-2007, 09:51 PM

Hey guys,I have question,for how many miles the timing chain is good on this cars?

DrewGerhan · #2 01-01-2007, 10:30 PM

I've heard every 100k miles. Somone else has told me 150k-200k. I would personally change it around 100k, since I'd rather do that than have a top end rebuild. "Insurance" But thats just me. Others will probally chime in too.

signalredcoupe · #3 01-01-2007, 11:22 PM

I'm sure you will find a ton of info with a search on this. The real issue is all the other stuff having to do with the chain that can fail it. The tensioner, guides & gears. Frequent oil changes matter also. Just changed mine after almost 300,000 miles & it had minimal stretch, but the guides & tensioner had had it. Paul.

#4 01-01-2007, 11:24 PM

Synthetic oil has also shown large reduction in chain and tensioner wear.

Sash · #5 01-02-2007, 01:02 AM

My car have 281K,the head was redone by privies owner about 100k a go he said to me that the chain was replaced than to,so looks like I am good for some time as far as the chain go.
I own this car for a three weeks now and so far I cant sense anything wrong whit the motor, sounds good, runs good, don't smoke almost at all, idles good, starts good,I put so far close to 1000 miles on her and she averages about 25 MPG,I don't know if this is dissent or not but I am very happy whit it.

Hatterasguy · #6 01-02-2007, 11:39 AM

They don't usualy break, on these engines. The 100k mile thing is more for the gas V8's. You can probably run 300k miles without having to touch it. But the chain does stretch and this affects timing, and performance suffers.

Next time you do a valve adjustment, check the chain stretch and see what you have.

DrewGerhan · #7 01-02-2007, 02:11 PM

Quote:

Originally Posted by Hatterasguy

They don't usualy break, on these engines. The 100k mile thing is more for the gas V8's. You can probably run 300k miles without having to touch it. But the chain does stretch and this affects timing, and performance suffers.

Next time you do a valve adjustment, check the chain stretch and see what you have.

Well, that is a big difference. Guess I can save some money and wait to do mine then.

Hatterasguy · #8 01-02-2007, 02:47 PM

Quote:

Originally Posted by YoungBenz

Well, that is a big difference. Guess I can save some money and wait to do mine then.

Yeah wait until you have the time and money, no rush. Simply check it the next time you adjust the valves.

My 603 is a different animal than your 617, but at 250k+ miles I was off about 2.5 degrees. The later engines like the 606's seem to stretch about 1 degree every 100k miles.

This of course is assuming the oil is changed, all bets are off if its an abused example. Most 606's are on a Mobil 1 diet as well.

Personaly I don't think its really worth checking the TC until you role over 200k miles.

DrewGerhan · #9 01-02-2007, 03:37 PM

Quote:

Originally Posted by Hatterasguy

Yeah wait until you have the time and money, no rush. Simply check it the next time you adjust the valves.

My 603 is a different animal than your 617, but at 250k+ miles I was off about 2.5 degrees. The later engines like the 606's seem to stretch about 1 degree every 100k miles.

This of course is assuming the oil is changed, all bets are off if its an abused example. Most 606's are on a Mobil 1 diet as well.

Personaly I don't think its really worth checking the TC until you role over 200k miles.

Yeah, I won't worry until the next valve adjustment. I'll check then. Its always started with minimal cranking (one bad GP), very low blow-by and I'm going to switch to synthetic oil next oil change. I should be good to go.

Sash · #10 01-02-2007, 04:18 PM

Thanks guys,sounds like my car is going to be O.K for a long time.