timing chain again???

[deadscoob 0]

Got a lateish highline, registered 5/97, done 130k now. It's got a slight rattle, which to me sounds like a heatshield/exhaust, but reading on here I'm beginning to worry it could be the timing chain.

I "thought" late VR6s had improved chains/tensioners, is that the case? What's the quickest way to check if there is a problem? Is there an idiots guide anywhere? !dodge

cheers in advance

[mtopple 0]

My timing chain went last week and cost me a fortune as the cylinder head went, head gasket had to be done and valves and tapets had to be replaced.

As you look down on the engine on the right side if there is a rattle I would get it done ASAP. otherwie start saving.

The job for the timing chain is long due to the gear box has to be removed.

The company that did mine are based in Berkshire off Jun 11 of M4 called Storm Developments.

[FishWick 21]

Some highlines and late Golf VRs did get the timing gear improvements/updates, but I don't know the change over year....I do know that an R reg Golf VR I saw at Stealth exhibited no wear at all in it's tensioner pad at 125K.

On the late engines (OBD2 mostly), the cam chain and sprockets were 'downgraded' from duplex to simplex, the upper tensioning pad was 'upgraded' to solid polymer from coated steel and the tensioning bolt was 'upgraded' to spring and hydraulic, from the older hydraulic only bolt.

Replacement engines from VW, even the ABV (2.9) use the newer components in the timing gear.

Following succesful trialling on my OBD1 ABV engine, Stealth Racing also now use the solid tensioner pad and spring/hydro bolt on Corrados and early Golfs when getting the chains done, because the old resin coated steel pad was such a liability.

So, in summary.....there are no hard and fast rules with this. No noise doesn't mean all is well, as has been proven on my engine and many others. My resin/steel tensioner was on the verge of collapse at 90K but was not making a peep. Other engines make an almighty racket....most noticable when holding the revs at 1200 when the engine is warm.

I would say that owners of late engines shouldn't get any noise at all as the tensioners just don't, or shouldn't fail like the older resin ones do. But that's not to say the head still won't need a rebuild etc.....

Chains actually snapping a link is very, very rare.....

The ONLY way to be sure is to lift the rocker cover and visually inspect the pad..... the VR6 is not a quiet engine, so there's no guarantee a noise you hear is timing chain related.

[deadscoob 0]

thanks for the info. Is it possible to tell whether the engine should have the upgraded tensioners etc from the engine number?

[Nerih 0]

i'll send you a PM with the guide ok.

[deadscoob 0]

cheers

[andy 0]

Kev, you say you are using the later tensioner and pad, are you therefore using a simplex chain too?

[FishWick 21]

Nope!

What happens in this situation is the duplex chain partition wears a groove into the centre of the late pad, about 0.5mm deep. This happens more or less straight away but from then till now (20K later), there is no wear at all on the rest of the pad and the centre groove is no deeper. So in other words, once the pad has 'shaped' itself to the duplex chain, no more wear should occur.

This is why when I opted to go down that route, the workmanship wasn't guaranteed as it wasn't a standard part for the engine, and if it let go, the bill landed on my doorstep and not stealth's.

I checked it recently when I changed the tappets and it'll go on for many, many 1000s of miles yet.

Reading between the lines, VW's intention all along was to retrofit the solid pad to duplex driven cams, otherwise they'd have made the solid pad just wide enough for the simplex chain....but as it happens, the solid pad is the same width as the duplex chain oddly enough!