Prospero seriously ill!

[Snoopy]

If it was just a belt jumping teeth seems odd full new engine.

[Rolfe]

Pass.  I literally have no clue.  Andrew, who has maintained the car from new, is quite frustrated.

He agreed it could have been the timer belt ("though it's way too young to expect that to fail"), and then the aggressive attempts to start it did the major damage.  But we're all just guessing.

[Edi35]

If it was just a belt jumping teeth seems odd full new engine.

Once the belt has slipped, valves and pistons will be out of timing and will meet in a major metal mashing. This could damage all the major parts of the engine.

[Egbutt Wash]

The tension in the timing chain relies on a big banana shaped block pushing against the chain.  It gets its push from oil pressure.  If your oil is knackered (and oil does go off in an alarming way) it might cause this failure. 

[Rolfe]

It's not a chain in this particular car, it's a belt.  And this car was serviced only three weeks before the incident.

[p3asa]

It's not a chain in this particular car, it's a belt.  And this car was serviced only three weeks before the incident.

Are you sure Rolfe? I thought the GTI was a chain and the R was a belt!

[Snoopy]

The Mk6 Gti uses a timing chain.  This is kept nice and tight by a hydraulic tensioner, running off engine oil pressure.  When the engine is stopped the oil pressure drops to zero and some oil in the tensioner can leak past it's stop valve, leading to a more sloppy timing chain.  This is when the chain can skip.  Constant turning over of the engine in this state can cause more skipping and in the end allow the valves to open onto the top of the piston, which is no good.

You often hear the sloppy timing chain on start up on all VW's TSI engines.

does turning it over not increase the oil pressure? As that's what your suppose to do to old cars when they stand for a ages unused.

[Edi35]

It's not a chain in this particular car, it's a belt.  And this car was serviced only three weeks before the incident.

Are you sure Rolfe? I thought the GTI was a chain and the R was a belt!

+1 GTI has chain (EA888) and R/ED's have belts (EA113) I think that's right.

[mike.]

Hardly complicated at all, how could it possibly go wrong 

[Snoopy]

Am I right in thinking that we know of 3 tensioners that have failed.
Were the cars all built same period?