Slowcrash_101

Nope you can totally get away with very light scratching marks. If it doesn't catch your fingernail it's fine. Belt tensioner or just the pulley?

insurgent

Actually just the pulley, not even the tensioner. Can't believe it took all this to suss that out, it really sounded like the noise was from the block. Engine was running rough too but I found that the loom to the coil packs at the back of the engine was severely frayed, some cables broken even, which was effecting the running. Not altogether convinced there wasn't a compression leak from the head gasket either. Got to get the head skimmed and get new gaskets now which is a pain, but at least I've got the chance to have the head pressure tested and be confident that everything is ok with the engine once it's back together.

Slowcrash_101

If you've never overheated the engine the chances of a blown head gasket are small. Do you lose coolant?

insurgent

So after having checked the big ends, little ends, crank end float, changed the belt tensioner, checked compression, checked the injectors, removed the head and checked the cylinder liners, checked the valves, checked the cams and cam towers, checked the cam timing gear, removed the belt to check ancillary pulley faults, and put the engine back together again carefully, then guess what: the bloody thing is still tapping!

What the hell can this be? There is nothing left that can tap? Apart from the noise the engine sounds great, and there is no loss of performance at all. The tap does not appear immediately from a cold start, but comes in after about a minute. It tends to disappear if you raise the revs, but it becomes much louder accelerating under load.

Any suggestions gratefully received! This is driving me up the wall...

insurgent

Could this just be the TCT? The chain is tight when the TCT is installed, and when I stripped down the TCT it all looked ok? What is the mode of failure with the TCT and could it be this despite it appearing to be ok?

insurgent

Just checked the tensioner again, the helical screw part is quite loose in the piston, is this normal or should it be tight and the looseness is indicating wear?

pin64

Hi, I'm new to the forums and very new to the S2K, so probably best to take what I say with a pinch of salt. But..

I recently fixed TCT clatter using the quick and dirty Dremel method (https://www.youtube.com/watch?v=DpyyZQEQgGE). The worm drive was really quite loose in mine, even after re-assembly, but having roughed up the surface a little the TCT noise was cured.

So I don't think it being loose is an immediate concern; seems it's just important for the surface not to worn be smooth.

The noise your engine is making is totally different the TC rattle mine had, so I'd be surprised if it was that. Saying that, from the efforts you've gone to it seems you've ruled out pretty much every other possible cause!

insurgent

Looking now as if the only possible cause left is piston pin failure. Can this really happen on a stock engine?

Billman250

I guarantee a loose or worn worm gear is not your problem.

Slowcrash_101

Can you post a new vid of how the car sounds now after everything you've done?