Worn Cams Audi A6 2.5 TDi - several questions...

[Gunner Bill]

2001 Audi A6 Quattro 180 BHP 2.5 TDi w/ 106500 miles,

My car doesn't know it yet but the apparently it could die at any time

After a trip to the garage to sort out an air locked fuel pump and an oil leak the mechanic told me that the cam shafts were wearing and that this could be imminently terminal.

This diagnosis comes from the slightly noisier than normal engine note and the rhythmic "chirrup chirrup" particularly from the right hand bank.

The timing belt/water pump were done 4000 miles ago and the problem was not evident then.

Given that a) he didn't offer to take all my money to fix it and b) I've known him for years and he is an excellent Audi VW specialist I am inclined to believe him.

I like the car and am presently inclinded to get it fixed by hopefully replacing the head(s) with refurbed units?

1) I'm expecting this could be done for less than £1500, is this unrealistic?

2) Should I perhaps not bother at all, the car is certainly not lacking in power suggesting that the wear is not too bad?

3) Could he be wrong?! If so what could it be?

4) How can I determine what type of camshaft it has (hollow or solid)?

5) Anyone know where I can get refurbed heads from?

BTW - It was this excellent thread that found me here, not much other info out there on this problem, cheers!

http://www.tyresmoke.net/forum/audi-a6-s6/124148-2-5-tdi-engine-any-good.html

Thanks BW2309 for shedding some light on this for me!

[Mook]

£1500 to replace the heads isn't realistic, unfortunately. You can tell the difference between the cams by tapping them, but you've got to know what sound to listen for, if that makes sense!

There's no reason to replace the heads though - replace the cams and followers as a minimum, which can all be done with the heads on. If you want to cough more cash, get the heads removed and get the valves re-lapped, but you really shouldn't need to do that.

[Chippy757]

From what I remember parts on their own will be approx £1700 (if oem) + many hours of labour(some garages tend to over doit). Your bill would be closer to 2500, if done by indy, more if by dealer. Get proper inspection done before you get anything replaced. Cams should last closer to 200k on v6 if engine been looked after...

At some places you might get whole engine rebuilt for few extra bob...

Mine still noisy even after cams replaced.

[BW2309]

The cams will be smooth steel with lobes that are clearly separate if the cams are hoolow. If the cams are solid the surfacr of the shaft itself will be rough and clearly cast.

On the hollow shafts the lobes can split and spin round on the shaft upsetting timing but on cast cams they can wear terribly! It's easy to see. Just pop the oil filler cap off and you can see one lobe. If you can't see it's tip just spin the engine on the starter and try again. The wear is very easy to see as over 1mm of wear is not uncommon!!

Here's a pic of a cast cam on a 2.5TDi with worn lobes. This one was bad enough to cause terrible idle vibration and lack of power.

[Gunner Bill]

That's brilliant BW'. I'll get a look at the cams when I return from my trip offshore.

The car is presently going like stink and has a smooth idle. As I said above this problem is only audible to the mechanic I use. I suspect that if he is right it's probably in the very early stages and will likely give me many more good miles of motoring.

Could a change in oil specifcation help prevent the problem from worsening?