bydand

Eventually got around to stripping down the A4 2.4 v6 1999 with only 73K Km on the clock to try and find out what caused the timing belt to snap.

Looks like someone has been in there before?

Water pump roller, is shiny on one side so may have seized at sometime.

timing belt shows classic signs of over tension, internal threads pulled out.

No dropped valve.

Looks rather carboned up on the pistons and valves.

valve contact and bent valves on 3 cylinders.

Had it for 2 days, changed the oil, plugs, air filter and brake fluid, vacuum hoses.

All not too bad, at 73K one would expect not, apart from the vacuum hoses which were shot.

Before the belt timing belt failed

Any suggestion, as too root cause of timing belt failure?

I am erring toward the belt was over tensioned when it was put back together, for whatever reason.

Your thought please gentlemen, before I put in back together.

Is it worth while changing the camshaft followers on the bent valve, or is there something to look out for, signs of damage etc.

thanks.


bydand

Prospeeder

Well 1999....its going on 2015 now. The same rubber belt. It failed from age most likely. Shiny spot on the water pump probably because the thing sat never running for so long, it cant just seize for fun for awhile then unseize lol.. The belt isn't going to shred from being slightly over tensioned. It would have made tons of belt whine from it being that tight that somebody would have to have taken it apart to correct it. The lack of use explains carbon this was probably driven 1 mile to the store once in awhile.

bydand

Thanks for getting back prospeeder.

The overall condition of the timing belt, which snapped, and serp belt were good, for a car with low milage 73K Km and well yes 15years old.

The the tail told when bought, was one owner little old lady, Bible in the back, driven only on Sundays etc.

Service history, first couple Audi, and then independents about annually.
Still cross hatching on the liners.

I will put it back carefully and see what happens.

Bydand

bydand

3 inlets and 4 exhaust valves changed out and a handfull of the hydraulic lifters.
Cylinder heads cleaned and rebuilt.

All back together and P1392 and a water leak.

Suspect one tooth out on bank 2 and water pump gasket, or thermostat housing.

Ran fine apart from the leaks and code thrown.

Rain stops play!

Damn.

bydand

All back together and P1392 and a water leak.

Suspect one tooth out on bank 2 and water pump gasket, or thermostat housing.

Ran fine apart from the leaks and code thrown.


Water pump Gasket nipped when boxing up.
Timing out one tooth on bank 2.

Now P1338..... progress??

x19

Is your engine AVK or just 3.0? x19

bydand

Not a AVK, AGA may be, A4 2.4 v6 30 valve, 1999.

why do you ask?

tvsdprasad

That was a costly-mistake done by the Audi Guys,the choice of a belt, not just the design and quality, was a contributing factor to the multiple failures on the Audi A4.

bydand

Quote:

Getting there.......
All back together and P1392 and a water leak.

Suspect one tooth out on bank 2 and water pump gasket, or thermostat housing.

Ran fine apart from the leaks and code thrown.


Water pump Gasket nipped when boxing up.
Timing out one tooth on bank 2.

Now P1338..... progress??

Ok, The P1338 would suggest the timing is now out on bank 1. Used the crank pin and the locking bar while adjusting the cam chain on the bank 2. So this should not have changed bank 1 timing.

Why would this not have raised a cam timing code to begin with, same as P1392?

Would the variable timing have compensated, and now the bank 2 is correct, this has thrown out the bank 1 timing?

Also spotted the plastic timing belt cover on the bank 1 has been renewed, date marked 2001 and the timing belt tensioner seems rather softer than usual. It was an original INA type, Just wondering if this was not the original issue, for someone being in there before, and removing the heads because of the belt failure. MMmmm.

All the inlet/exhaust valves looked original, but the heads had been off before and the cylinder head bolts reused.

Just can't understand why, unless the belt broke because of the tensioner going soft, and not damaging any valves, but damaging the timing belt cover.

Also have a strange noise from the front of the engine, timing related? sounds more like its coming from the hydraulic steering pump when you increase the revs? Not mechcanical type noise more like restricted fluid as thou the steering fluid was too viscous and the steering pump was struggling. SG Oil and levels normal and steering turns.

bydand

Well, P1338 cleared, one tooth out again on bank one this time.

Runs and no, well not many codes.

Decided to change out the ATF and filter, and power steering fluid. Twice??

and found the reason for the mechanical noise from the front of the engine.

see photos below.







Bolt from





Yes, do not buy chemicals is similar looking bottles and proceed without looking.
Just after putting the second bottle in of ATF, realised it was Coolant. Damn.

The other photos, is/are what I found on opening the ATF,

loose bolt on the magnet.

This was returned and all the other bolts checked for tightness.

The last guy in there scratched his name and date on the inside of the cover, the bar-steward.

Changed out the Power steering fluid with Febi 06161 green Synthetic to VW TL 52146,G 004 000 M2 and seems to be OK. S noise was not coming from the power steering pump.

The noise and rattle, seems to be coming from the cam chain tensioner(s), which would make sense, as would not go down too far when removing the cams, and would be explain by the moisture in the engine oil and laying a couple of years now.

Also on the trip down to the petrol station, the tyres would appear to be flat spotted, and the tank level gauge is not working, one of the error codes.

Apart from that, all is good?

Anyone know if you can free up a cam chain tensioner, open up clean up etc. Very low milage on the unit.

Ho Hum?