All Things Mk5 > How to Guides / Troubleshooting

Top end clatter 2007 GTi.

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RussH:
I know this is a pretty impossible ask but could anyone give me some ideas on this top end clatter?
I've searched this forum and tried everything I can think of.
Replaced fuel pump and cam follower.
New cambelt and tensioners.
Removed the cam cover and everything looked normal. No wear visible.
Listened with a stethoscope and pipe to try to pin the source down as best as I can. The noise seems to be coming from the centre rear, possibly slightly to the left (cam belt end). The heat shield above the turbo isn't moving/rattling but that's the area it seems to be coming from.
It's done 80k miles. Good condition, no running/performance issues.
The noise only starts when it's up to temperature.
It disappears as soon as it's slightly above idle, around 1050rpm.
I do have videos with it running minus the air box but I don't think I can upload a video?

LC5F:
Could be an exhaust leak at manifold - or even down pipe - they can make some strange noises, and this ties in with warming meatal expanding creating the leak/noise.

When you checked the valve chain and tensioner - you did check that the tensioner is keeping the chain taught?
If it was something in the valve train I suspect it would be constant - I can only think of stuck/gummed up hydraulic lifter, but thats a bit of a reach

RussH:
Thanks for the reply. I hadn't thought about an exhaust leak. I'll check that.
I haven't checked the cam chain. I wasn't sure if it was possible to just remove the cover to expose the chain?
To me it doesn't sound like a sticky hydraulic lifter. But who knows.
I should say it's been to two garages (one a VW specialist) neither could figure it out. The specialist suggested, as a process of elimination, testing the oil pressure. But apparently that's not an easy job.

RussH:
Well I've made some progress!!
Using measuring block 93. When it's cold (no noise) the spec. is 28 degrees KW. Actual is rock solid at 27.5 to 28KW.
Once it warms up the actual starts to move between 24 and 28degrees KW. As it drops to 24-25KW this corresponds directly with the noise.
So. Could this be the oil seals in the variable cam timing module? As the oil thins (with temperature) this causes the instability/variation between 24 and 28?

LC5F:
Yes - the cover can be removed, but is a bit involved, requiring HPFP to be removed and a few of hidden bolts - and then it spills a good amount of oil out, so be ready with rags.
When you remove the cover it needs to be level to not damage the ceramic seals that control the VVT phaser.
For best visual and physical access I recommend both battery and battery tray out.

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