Timing Chain rattle

[Mack 6]

Hi there guys.

I have done a few searches and got a few ideas, but am having a small issue with the timing gear on my AU2 6cyl.

I drive the car reasonably hard and do some racing, but I have had to replace the complete timing gear twice in the last few years due to snapped tensioner.
I only get noise for a second or two on start up (until there's oil pressure) and if the car is revved, as soon as you back off there is a rattle of chain on guide (I'm guessing)
I have spoken to Bruce Heinrich who recommends a better quality chain which won't stretch as much, and while I am considering this, I should add it has a JMM dev 3HL cam in it. I found a thread saying many JMM cammed cars have a similar timing chain issue, does anyone know why?

Whilst I'm sure i'll get a good result with another cam, if i can fix the problem with slipping in a different chain, I'll do that for now.

I am running a synthetic 10w30 oil atm, thinking of something slightly thicker just to help out. Any recommendations there as well would be appreciated.

[Day-mow]

Something's deff not right man. Theres a few of us AU Boys that push our cars pretty hard and have no timig chain issues. I replaced mine hmm a yr ago but only because I have the timing cover off. Is your tensioner tensioning correctly? That's my 1st though.
I also run the same oil. No issues

[Mack 6]

Well, first time was 2 1/2 years ago, got a new tensioner, guides and chain fitted, no probs. Then 12 months ago, got a nasty rattler and timing went out. Tensioner had snapped and chain and guides damage. Replaced again and now I have the initial rattle, and when I back off the revs (in neutral). If the tensioner failed first 2 times, I'd have a new one in which should be ok?
maybe the stretched chain. I dont remember the brand (cheapie) but I did send the second one back after it died, never heard anything back!

I did see a how to on checking/resetting the tensioner by rotating the outer ring to tighten and then an allen key or soemthing (will have to look it up), but i think my best bet would be a visit to bruce and check everything while he chucks on a new HP chain.

[FGII-XR6]

sounds like a problem with the tensioner check it isn't backed off that could cause rattle. the AU isn't usually prone to timing chain dramas and the factory chain is quite tough

[Uncle_Ken]

Originally Posted by au3xr6

sounds like a problem with the tensioner check it isn't backed off that could cause rattle. the AU isn't usually prone to timing chain dramas and the factory chain is quite tough

I had noise and I reset the tenisoner many times it turns out the noise was not the tenisoner but a broken lifter (see thread below)

http://www.fordforums.com.au/showthread.php?t=11351037

Just a thought

UK

[Mack 6]

Thanks Kev, but we have changed the lifters last time and the noise is def from behing the timing cover.

au3xr6, bearing in mind this is prob some of the shelf replacement part, if it stretched too much, can the tensioner continue to apply enough tension on it? I will get that checked before pulling stuff out, but I am still thinking a new chain could be on the cars.

Point to note. It got hammered with burnouts (matty31 bouncing off the rev limiter) and a total of 10 high speed runs up Mount Alma last weekend, the noise is no worse (only really noticable at startup for a sec, and i don't rev the bejeesus out fo it), it even towed the trailer the 100km home without any major issues.

Keep on top of it I think!