cam chains snapping on a VR

[Adam Darby 0]

just wondering if anybody has every had one snap on them. If so what was the damage, i no its gonna be bad but just out of intereast. cheers

[andy 0]

Not had one snap, never heard of one snapping but I bought one as a project where the chain had slipped on startup. 9 out of 12 valves were bent but that was about it apart from the mullered tensioner and guide rail. I would expect valves and pistons to be damaged if the chains snapped in normal driving, as a minimum.

[Adam Darby 0]

its Probably the tensioner breaking up that causes the chains to snap. can the chains touch any internal parts thorugh being lose and break or wear them out.

[andy 0]

It is indeed the crap tensioner pad breaking up that causes problems. There's not really much for the chains to touch as they run in guides (plastic) and you'd probably get chain slippage before damaging anything else if they were that loose.

[Adam Darby 0]

is there any way of telling when the tensioner is gonna go or does it just go all of a sudden

[andy 0]

Its not the tensioner that fails its the curved pad that the tensioner acts on. It looks a bit like a brake shoe and the material wears away over time until it gets to the rivets and bits of tensioner pad go every where etc etc. It can be inspected for wear but thats not a 5 min job.

[VR6 0]

Not heard of one breaking in the 3 years or so that I've been on the forum ...

 

Sure they must have done though!

[Adam Darby 0]

right. can you inspect the curved pad then

[andy 0]

Yep, but from memory I would say you need to take the inlet manifold off, cam cover off and chain cover off. Which would therfore mean removing a lot of other ancilliaries like coil pack, ht leads etc.

[RW1 0]

Know of one VR6 that busted the timing chains at 150kish but maintenance on the engine was very dubious to say the least so may be taht was an extreme case.

 

The chain tensioners is usually the issue as some above have experienced.

 

Should plan to do a timing chain & tensioners change when the clutch or gearbox is off in the mileages above 130kish as a matter of preventative maintenance.

 

.

[dr_mat 0]

I've heard of a few VRs snapping their chains (maybe four or five, counting Golfs and Passats..), but it's hardly an epidemic. Once the tensioner has worn down the chain can flail around at speed, and it's when it does this and bounces off the casing that it's more likely to have problems. The plastic guides have been known to break too, again, increasing the likelihood of the chains bouncing around.

I've also heard of lots of stories of VRs with rattly chains running like that for tens of thousands of miles with no ill effects, so I don't think it's something that you really need to panic about so much.

[rixy 0]

ive heard of one snapping, and coiling up at the bottom of the engine around the lover sprocket,shearing it off. Was about 2k for a new crank or summit,was told this by my mate who's a mechanic. Also bent valves etc.

[Adam Darby 0]

to inspect the tensioner is it the same job as cheaking the chains (can you see the tensioner from the inspection cover)

[Geo 0]

Yeah it's the same thing.

 

The chain doesn't have to snap to damage the engine. When the lining disintegrates on the tensioner pad it can cause the timing to slip and bend valves etc. Happened my Vento VR6. The chains were intact but the tensioner pad had fallen to pieces.

 

On any VR6 with 100k ish miles on it it is definitely worth taking off the cam cover and upper timing cover for a look, but as someone said it's not as easy a job as it sounds as you have to remove a lot of other stuff first, not difficult just time consuming.

[Kevin Bacon 5]

ive heard of one snapping, and coiling up at the bottom of the engine around the lover sprocket,shearing it off.

 

If you're quick on the clutch or if it snaps at low speed you might be lucky. If it snaps at say, 90mph, then valves, pistons and crank case are all going to be smashed to bits, writing the engine and gearbox off effectively.

 

Stealth have seen only 2 VR6s with snapped chains in the 10 or so years they've been fixing them.

 

A lot of engines use chains and have the same service requirements, but it's not as widely publicised - seemingly - as the VR's. Take the E30 M3 for example. If that chain goes....you're looking at well over 4K for a new engine and it costs £1500 to change the chains at BMW, as opposed to £600 odd at Stealth for the VR.

 

Current Ms use chains, S4 V8 uses chains, 16 and 20V heads use chains and so and so forth....

 

It's a proven timing method but nothing lasts for ever.

[Adam Darby 0]

no its just my mates car has gone into a garage for a service its done 160k and has no sign of a cam chains change in its history. The car sounds very rattley in the engine, when you stick you ear on top of the inlet manifold it doesn’t sound like its coming from the tappets, but when you listen to where the timing chain's are it sounds and feels like the rattle is coming from there but the garage said the chains look ok. you would hope that the garage would of checked the tensioned as well, but do you think the garage could of just looked at the chain for wear or something stupid like that.

[dr_mat 0]

They could have done that. They could even have looked at the aux belt and said "yeah mate your chains are fine".. But paranoia only buys you repair bills .. ;)

[Geo 0]

It's highly likely that unless the garage is familiar with VR6 engines that they just looked at the chain and said it was fine (which it probably is) without looking at the top tensioner pad at all.

[Adam Darby 0]

Right so if the has done 160k and the chains have not been done and in a best case its had its oil and filters done regularly how worn would you expect the tensioner pad to be.

[Geo 0]

I don't know, can't be exactly great after 160k. My vento had 119k with full service history when it let go.

[Trig 0]

I'm not going to bother doing my chains. If they go, which I think is unlikely, then i've got an excuse (for the girlfriend) to put a 24v or R32 lump in there. :)

 

If it happens I don't expect it to be in the next year or two.