OM651 timing chain tensioner

[vitowill]

Hi all, newbie to the forum.

I have a 64 plate Vito, which I like a lot, it’s powerful, quiet, auto, air con, nice van which i intend to keep.

A few months ago I started hearing the dreaded rattle on cold start, not every time but maybe 50% of the time.

I’ve replaced tensioners on vehicles previously and it seems to be fairly standard procedure with a few miles on the clock.

Anyway I replaced the tensioner on the Vito, I used an Ina item, and I’m really surprised that the noise is still there! Less for sure, maybe only 2 out of 10 times but still there a bit.

Any thoughts?

Thank you

 

[jasonh]

I don't know about the OM651 in particular but often with cam chains a new tensioner only eeks out the last few miles of the chain. The fundamental problem is the chain is worn and stretched...and often the chain guides are close to failure too.

 

[Simonsb]

My A200 was doing the same. The dealership attempted to just change the tensioner but the rattle was still there. It ended up have a chain on. The car has covered just over 104000 miles. Luckily the guides were ok otherwise it would of been an engine out job.

 

[vitowill]

Thanks for the replies.

It did cross my mind that it’s possibly the actual chain but I thought for the sake of 40 quid it was worth a shot with the tensioner.

The only thing that nags me though is the fact that once that 2 second cold start rattle has gone it makes no noise whatsoever, from tick over to max rpm. I’d say it’s probably the smoothest diesel I’ve ever driven. Surely if it was the chain it would rattle all the time?

I was wondering about the oil pump, maybe the oil filter housing not keeping any oil etc. The engine starts instantly after the glowplug light has gone out, I wish it would crank over for a turn longer giving a bit more time to build pressure!

 

[Simonsb]

Mine was exactly the same as you describe. Would probably rattle once a week, if that on mornings. When the indi removed the old chain they even stated, no sign of wear. However i insisted they change it as it was stripped down, and Its been silent ever since.

 

[gusferlizi]

Thanks for the replies.

It did cross my mind that it’s possibly the actual chain but I thought for the sake of 40 quid it was worth a shot with the tensioner.

The only thing that nags me though is the fact that once that 2 second cold start rattle has gone it makes no noise whatsoever, from tick over to max rpm. I’d say it’s probably the smoothest diesel I’ve ever driven. Surely if it was the chain it would rattle all the time?

I was wondering about the oil pump, maybe the oil filter housing not keeping any oil etc. The engine starts instantly after the glowplug light has gone out, I wish it would crank over for a turn longer giving a bit more time to build pressure!

The V6 diesel ECU fires too early with a bad crank sensor. Don't know enough about the 651...

A hydraulic timing chain tensioner only wears out when the chain (and sprockets) is out of spec, so it generally is pointless to replace (at best) without full inspection of the timing system.

Even when it "hides" the rattle the overall system backlash tends to increase, making everything else go downhill faster.

 

[Tonygw]

Just to add, mine was the same, would rattle one in 5 starts. gradually getting more frequent. A new chain sorted it. Wasn't to expensive either.

A lot on hear say to not use the start stop feature if it has it, as this aids chain wear.