Audi 80 AAZ timing belt follow up.

[minny]

Right, the only belt that was off was the timing belt, the other two below where on, one I believe is the V belt, not sure what the other is called, but you will.

The only belt not on was the timing.

When turning it there was a point when turning when it was more resistance in the wrench (which I assumed to be compression point), then it went easy for a bit, then resistance again, this was at proper regular intervals.. But, it was pretty much easy to turn with plugs and injectors in.

So I'm thinking squashed valves, which is no surprise really.

But, no harm in being optimistic!

[A4 Lad]

Definitly squashed valves friend. Remove the head, take your time and even take pictures if your not sure about something. Take the head off and see whats happened.

[minny]

Well, I have nothing to lose and quite a bit to learn!

[Tobster]

Sorry if I sound patronising, but to fully describe:

The timing belt synchronises the camshaft (which opens the valves); with the crankshaft (which moves the pistons up and down).

Most car engines (probably 100% of diesels) are inteference engines; which means the highest physical place that the piston reaches is higher than the lowest place that the valves reach; so if the timing belt fails during operation they will collide, usually destructively.

Because of this, it should not normally be possible to turn the camshaft through a full revolution independantly from the crankshaft without a piston fouling on a valve (you'll hear a metal ping and not be able to turn the camshaft further) - unless the valves have been damaged (compressed) to the point that they are no longer intefering with the pistons.

[A4 Lad]

If this is only the crank turning with no timing belt on you have 100% bent or broken valves !! You would want it to hit solid ! If your turning your crank a full cycle and its not hitting a valve then somethings wrong as at least some valves will be in the open position as each of your 4 pistons goes fully up. Its a no brainer really !!!

Yup

[minny]

Yet more questions,which I must apologise for and thank you for being so helpful thus far.

There are a few jobs on cars I'm wary of tackling for safety reasons, one is the fuel system. Now it looks like you have to remove the fuel pipe assembly. But in everything I have it is not quiet clear how you handle the fuel, other than be careful it's under high pressure and it can squirt out and kill you dead.

I assume you don't have to remove the whole fuel injection pump. Is it a matter of clamping the two fuel feeds that lead to the fuel injector and just have some spillage when unbolting the pipes? It does mention the pressure inside this pump is a particular problem on post October aaz engines, I'm assuming taking off the pipes will affect this.


Can I put a socket on the centre bolt of the fuel injection pulley to line up the locking holes? if so I assume this is best done before the pipes are taken off, it does seem very difficult to turn.


Also is it OK just to unbolt the manifold away from the cylinder head before taking it out, or take out the cylinder head with manifold then separating.


Thanks.

[Tobster]

As far as I'm aware (to devoid my comment of responsibility; if you've heard otherwise don't assume that I'm correct!) the injector spray is only dangerous if it comes from an injector. From a disconnected injector pipe or union it will just dribble out even if the pump is being turned by the engine.

As for the injector pump and manifolds; remove them if they will make access easier. The pump/manifold-cylinder head bolts, where fitted, won't be particularly tight even if the parts have to be seperated later. Bear in mind new manifold gaskets will probably be required on disturbal.

You can turn the injector pump by the sprocket nut. Just check that the sprocket doesn't need to be removed if you want to remove the injector pump (it does on the 1Z, it didn't on my old 306's XUD9TE).

[A4 Lad]

As far as I'm aware (to devoid my comment of responsibility; if you've heard otherwise don't assume that I'm correct!) the injector spray is only dangerous if it comes from an injector. From a disconnected injector pipe or union it will just dribble out even if the pump is being turned by the engine.

As for the injector pump and manifolds; remove them if they will make access easier. The pump/manifold-cylinder head bolts, where fitted, won't be particularly tight even if the parts have to be seperated later. Bear in mind new manifold gaskets will probably be required on disturbal.

You can turn the injector pump by the sprocket nut. Just check that the sprocket doesn't need to be removed if you want to remove the injector pump (it does on the 1Z, it didn't on my old 306's XUD9TE).

This is correct. Just get tore into it ! Posting aint gonna get it done ! How long have you been thinking this one over now ????

[minny]

This is correct. Just get tore into it ! Posting aint gonna get it done ! How long have you been thinking this one over now ????

Quite a long time my friend. I like to do my homework first, see if it's financially viable out of my league etc.

The super caution comes from when I changed and oil filter and ruined an engine

But the tearing is iminnant, just some last make sures.

Don't want to be spending up to 200 quid just to find I can't get the timing marks back or screw up the fuel system.

[A4 Lad]

Quite a long time my friend. I like to do my homework first, see if it's financially viable out of my league etc.

The super caution comes from when I changed and oil filter and ruined an engine

But the tearing is iminnant, just some last make sures.

Don't want to be spending up to 200 quid just to find I can't get the timing marks back or screw up the fuel system.

Have you started the job even ?