timing belt jumped

[mdm]

story goes like this,

went to go home from work on wed night, the car (aby engine 159,000miles) started but died instantly. it turned over,even pulled the top half of the timing belt cover to see it the belt was still there and it was, but no sign of life. so i pull the codes off the ecu and it came up with 2113, hall sensor fair enough i though, so i decided before i buy one i'll pull the old one off.

got the time belt cover off completely and the **** hit the fan, the belt had no tension in it at all. there was a good half inch of movement, it looks like the tensioner has not moved.

so i retensioned the belt and tried to turn it over by hand, but it just wasn't going easy, time to check the timing marks i thought, put the crank on it's mark and well the cam was a good 15 or so teeth out.

got the cam back to were it should be and turned it over by hand. Alot easier to turn over now. still not feeling good about it, i got the compression tester out.

so cylinder 1, 3, 4, 5, are all around 10 bar, but cylinder 2 is only 3 bar.

so, the car will idle but a vibration can be felt thought the car, (snub mount wasn't correctly connected) and if i disconnect each coil pack it gets really lump bar cylinder 2 it only get lump after a few seconds, (feels like it's half running on cylinder 2)

so my problem is i don't know were to go now, I've had the cam cover off, and non of the 4 valves on cylinder 2 are stuck down so to speak, they all seam to sit up against the bottom of the cam.

I'm not really in the mood to pull the head off but, i will if it's needed.

any body got any suggestions

Mark

[BRY]

Pull the head off.
If the valve is slightly bent the head of the valve may snap off if you continue to run it.
That will cause masses of damage to the cylinder head when it gets hammered about inside the combustion chamber by the piston.

[mdm]

But would a bent valve still give you 3 bar of compression.

[BRY]

A bent valve may loose you 7 bar if it's not sealing properly.
It may be only slightly bent.

[S2central.net]

100% agreed with Bry on this one - smells like a bent valve that isn't sealing properly - you have been very lucky here (if thats any small upside from the situation).

Paul

[UrS4boy]

It may be only slightly bent.

Slightly bent is like slightly pregnant. Either way, somethings been screwed (so to speak).

There will be bent valves on Cylinder 2. Easily fixed. (Costs a head gasket, head bolts and time). Might want to do valve guides while the head is off.

[S2central.net]

And a timing belt, tensioner, EM bolts and an argument with the exhaust, a water pump, thermostat, water link pipes and 'sundries'

Like the slightly pregnant comment - good analogy !

Paul

[mdm]

the timing belt, tension and water pump will as be changed.

fun thing is, the timing belt was changed at 155k just before i bought the car, guess they never did a good job or didn't change the tensioner, i thought i had this area covered

moral of the story is always replace the tensioner with the belt

[MGaz]

Slightly bent is like slightly pregnant. Either way, somethings been screwed (so to speak).

comment of the week! i think.

[S2central.net]

the timing belt, tension and water pump will as be changed.

fun thing is, the timing belt was changed at 155k just before i bought the car, guess they never did a good job or didn't change the tensioner, i thought i had this area covered

moral of the story is always replace the tensioner with the belt

Who did the previous timing belt service then? Name and shame 'em !

[Graham]

I had a timing belt done in 2003 which failed 9000 miles later costing me all new inlet valves, new guides, new.........
The cause was the garage thought like most Audi's the crank pulley bolt should only be tightened to 250Nm (as opposed to 450Nm) The bolt came out the key in the pulley sheared (Replace that aswell).

[mdm]

got some prices, thought id run them by you guys

inlet valves are £9, exhaust is £19-20 each, £60 for stripping, cleaning, reseating the valves, skimming and rebuilding it

also need the following

Timing Belt
Water Pump (this is an exchange item, do i have to take the old one out first)
Cam belt tensioner
Crank Pulley
Bolts to fit Pulley
Crank bolt
Crankshaft Oil Seal
Turbo to EM bolts
Turbo to down pipe bolts
Turbo to EM gasket
Turbo to downpipe gasket
2 wastegate bypass pipe gaskets.
Head Gasket (what one rs2 or aby one)
Head Bolts (as above are these the same as the rs2 ones)

also were to get the above,

any thing else

Who did the previous timing belt service then? Name and shame 'em !

i'd love to but i haven't a clue who did it, it was done before i got the car over in england, all i have is a receipt for the belt not the work

[S2central.net]

Doing this yourself ?

[mdm]

Doing this yourself ?

everything bar fixing the head

[S2central.net]

http://www.s2forum.com/forum/showthr...t=26409&page=4 is mighty useful

Go to VAGparts.co.uk for everything you need - tell them I sent ya and ask for the S2 forum discount

Other things to consider when you are in this deep -

- The head gasket will be steel item for ABY - common with RS2

- Head studs from ARP - expensive but higher spec and re-usable (stock items are throwaway)

- New bolts for the PAS pump pulley

- New auxiliary belts (PAS, AC & Alt)

- New thermostat

- New water link pipes at thermostat and water rail

- Uprated snub mount with modified SQ bracket and A4 rubber - I posted on that

- MarkH 70-60mm reducer hose on the intercooler - better than O-ring thing

- New bolts for tensioner, coolant pump & thermostat housing

- If either of the oil pressure sensors/switches look leaky/sweaty now is the time to replace them - same goes for knock sensors as they are a PITA otherwise

- Only other thing I can think of is the cam cover gasket kit... Oh and the PCV breather valve which can also be a beeatch to access


Make sure you have a proper crank locking tool - I got the loan of one, but its not mine to offer onwards but I can ask if you like.

Cheers,

Paul