tdi timing altered after belt change

[cypher007]

about a year ago i had the timing belt changed at SEAT. i recently checked the timing with vag-com and its way out compared to where it was when i first checked it, some months before the belt change. it was roughly in the middle of the graph, its now at 9o and "too retarded to plot" according to vag-com.

so i had a couple of vag guys at work check to see if they could adjust it, but they said it would be better to take it back to SEAT, as it need locking off and adjusting. they also said the belt tension seemed rather excessive.

now there theory is that the SEAT dealer has done a tricky change, ie they havent locked off the engine, undone the cam and timing pump sprocket bolts, tensioned the belt, and set the timing up.

so im off too SEAT next Monday. now SEAT are saying if theres nothing wrong its a chargeable job . so i dont go there and look a ****, is there any other things that could have knocked the timing out eg. crankshaft sensor faulty?

 

[cypher007]

hello

anyone?

 

[James_R]

well the main question to ask is "is it causing any problems?" if not then just leave it.

If you read the ross-tech website it states that the ignition timing can not be adjusted electronicly on the pd's.

I've never checked timing on vcds because the only crystal clear way of checking is by locking the cam and the crank. The pd's ecu is very sensative and any timing faults will show up regardless of how small.

Also another thing to bare in mind is the thickness of the pd belts - they will have ALOT of tension on them once fitted.

 

[Muttley]

MJ, TDI 110 is the last of the non-PD engines Distributor pump diesel, timing set by the toothed belt which also drives the cams. What cypher007 is reporting sounds like the timing has slipped a tooth. However I'd expect an engine so far out to have major loss of power.

I suppose it may be that the dealership has tried to remedy a slipped belt tooth by retiming the pump, only to find there isn't enough adjustment there.

cypher007, it depends on how much you trust your readings out of VAG-com. If they show a fault with the injection timing then there is a fault to be adressed.

I can't think of anything else that would cause the symptoms of a slipped timing belt. Faulty sensors will stop working rather than give signal at the wrong time.

 

[techie]

You are supposed to dynamically check the pump timing after changing the belt and adjust as required. However a new belt will alter the timing especially if it's over tight.

 

[James_R]

MJ, TDI 110 is the last of the non-PD engines Distributor pump diesel, timing set by the toothed belt which also drives the cams. What cypher007 is reporting sounds like the timing has slipped a tooth. However I'd expect an engine so far out to have major loss of power.

I suppose it may be that the dealership has tried to remedy a slipped belt tooth by retiming the pump, only to find there isn't enough adjustment there.

cypher007, it depends on how much you trust your readings out of VAG-com. If they show a fault with the injection timing then there is a fault to be adressed.

I can't think of anything else that would cause the symptoms of a slipped timing belt. Faulty sensors will stop working rather than give signal at the wrong time.

Forgive my stupidity. I over-looked cypher007s sig and missed that its was a none pd tdi.
The none pds can have some slight adjustment carried out using vas equipment or vcds (which is covered on the ross-tech site).

Other than that i agree with you muttley, sounds like the timing may be very slightly out.

When fitting a belt on the 110 and 90 tdis alot of people cheat, mainly by not locking the cam (because it means taking off the cam cover) and then only locking the pump and as you have mentioned the timing can then move slightly when the tension is applied (this is normally counter-acted by turning the crank back by 1 tooth) but it appears as though this may have not been done.

 

[cypher007]

update

i took it back and:

they say dynamic timing it isnt a procedure the elsawin pro requires them to do on an ASV .

they will take the belt off an refit it to see if that helps .

SEAT say it does need doing.

my old copy of elsawin says it does need doing.

dealer double checks and says that section of elsawin doesnt apply to the ASV engine .

SEAT talk to dealer, then start to back out of there helpfull position, saying they hadnt realised i had the work done 14 months ago. i said i would like her to talk to them before i have the belt changed, to confirm they will do the timing, she says she will try and talk to them.

what would you guys do? im reluctant to let them neer the car anymore.

 

[Muttley]

What doesn't need doing? Locking the camshaft and the injector pump? Of course you do: if their version of Elsawin says they don't then it has a mistake, one that Seat needs to be aware of and rectify. But it's more likely they are misreading it, or worse, simply lying.

With a distributor pump diesel, you have to retain the relatioinship between cam timing and the injector pump timing precisely. You don't need Elsawin to tell you that.

Locking the camshaft means taking off the cam cover, so it may be that they haven't bothered to go that far. If that's the case, the camshaft will have turned as soon as the belt was removed, from valve spring pressure.

 

[cypher007]

nope

its the dynamic timing of the diesel pump there saying it doesnt need. there saying you can just lock the pump with the locking pin change the belt then take the pin out. when i took it back they just checked the timing marks on the engine lined up with the ones on the sprockets. the VAG guys at work recon the belt is too tight as well.

 

[silver surfer]

did an asv today you remove servo pump from end of cyl head .then remove cover on gearbox to see timing mark on fly wheel .check pump lock position is around 1 o'clock .line flywheel timing mark up .put locking pin in pump .then bolt lock plate in to rear of cyl head to lock cam .unbolt cam pulley and tap free undo pump bolts*3.change belt and pulleys and tensioner refit belt and top pulley tension belt to marks on tensioner .check position of timing marks on flywheel then tighten cam pulley bolt and pump bolts*3 remove locking devises and your done .its very rare you would check commencement of injection point but they very on engine code etc which you are looking at through measure block 00

 

[James_R]

the seat tool for locking the cam can only be used with the rocker cover off, so they've probably cheated and not nothered.

 

[silver surfer]

only on the old tin metal rocker covers do you take it off alloy rocker covers you remove servo pump on end of head to right in this pic http://media.photobucket.com/image/vw asv engine/ardy-photo/underbonnet/enginebay-vac-sol.jpg

 

[James_R]

Yeah but the genuine vag tool is not the same as the laser tools style version which bolts to the head so if the seat dealer were going to use the genuine tool it would require them to remove the cam cover.

 

[silver surfer]

well i didn't as i work for dealer and the vag tool bolts on the end your talking of the early mk1 tolly and golf mk3 engine.

 

[James_R]

I'm also from a dealer and we have this one for the asv engines (the pictures are from elsaPro for a 2004 reg leon):

This is it fitted (with the cam cover off):

Here is the laser one which bolts into the vac pump holes:

 

[cypher007]

back again

) if they didnt undo the cam and pump sprockets when they did the belt change, could it cause the belt to be over tensioned between the cam and pump sprockets?

2) is it ok to do the timing with it like that? or am i going to have to take them up on there offer and let them take it all off again? because if the belt fails they could say "well we did offer to redo the job but you didnt have it done".

3) could we undo the cam sprocket and pump sprocket to releave the tension? then do the timing.

i dont want to spend another £300 having the belt re-done at another dealer. i was having this one changed because the previous owner had it done by a back street garage which didnt replace all the cam belt rollers, and one of them was rusty and picking up black off the belt!!!

 

[Muttley]

cypher007 wrote

1) if they didnt undo the cam and pump sprockets when they did the belt change, could it cause the belt to be over tensioned between the cam and pump sprockets?

No, what will have happened is that as soon as any locking devices were removed the cam and pump would have shifted slightly, putting the timing out. Only the cam sprocket should be loosened off.

Standard process is to lock the cam precisely, with shims and feeler gauges (with the cam cover off), lock the pump, take off the old belt then loosen the cam sprocket bolt a fraction (holding the pulley with one of the long-handled tools in this Lasertools set, NOT using the locking tool to stop the cam rotating) and tap the cam sprocket from the back with a punch (you have to have the cam cover off to do this). Loosening the cam sprocket lets it adjust to any slight differences between the old an new belt. The you retension the belt and only then tighten up the camshaft sprocket to the cam. Finally, the locking tools get taken off. This all makes sense to me, taken from Elsawin. Done this way the relationship between cam position and injector pump timimg should be retained exactly.

Since it has been botched once, the relationship between cam and pump is now no longer correct and the pump needs to be retimed, which is what you found out in the first place.

2) is it ok to do the timing with it like that? or am i going to have to take them up on there offer and let them take it all off again? because if the belt fails they could say "well we did offer to redo the job but you didnt have it done".

They don't need to take the belt off again, but they will need to loosen the pump sprocket to realign it, so it's the same amount of work. The expense of the belt itself is tiny compared to the labour, so I wouldn't argue about it.

3) could we undo the cam sprocket and pump sprocket to releave the tension? then do the timing.

Undo the cam sprocket without all the locking hardware in place and you will disturb the timing, more than it is already, as the cam will shift, driven by the valve springs.

i dont want to spend another £300 having the belt re-done at another dealer.

Changing the belt again won't help, you need the pump timing redone.

i was having this one changed because the previous owner had it done by a back street garage which didnt replace all the cam belt rollers, and one of them was rusty and picking up black off the belt!!!

The idlers aren't usually changed, I don't think, unless you ask them to.

 

[cypher007]

cypher007 wrote

1) if they didnt undo the cam and pump sprockets when they did the belt change, could it cause the belt to be over tensioned between the cam and pump sprockets?

No, what will have happened is that as soon as any locking devices were removed the cam and pump would have shifted slightly, putting the timing out. Only the cam sprocket should be loosened off.

Standard process is to lock the cam precisely, with shims and feeler gauges (with the cam cover off), lock the pump, take off the old belt then loosen the cam sprocket bolt a fraction (holding the pulley with one of the long-handled tools in this Lasertools set, NOT using the locking tool to stop the cam rotating) and tap the cam sprocket from the back with a punch (you have to have the cam cover off to do this). Loosening the cam sprocket lets it adjust to any slight differences between the old an new belt. The you retension the belt and only then tighten up the camshaft sprocket to the cam. Finally, the locking tools get taken off. This all makes sense to me, taken from Elsawin. Done this way the relationship between cam position and injector pump timimg should be retained exactly.

Since it has been botched once, the relationship between cam and pump is now no longer correct and the pump needs to be retimed, which is what you found out in the first place.

2) is it ok to do the timing with it like that? or am i going to have to take them up on there offer and let them take it all off again? because if the belt fails they could say "well we did offer to redo the job but you didnt have it done".

They don't need to take the belt off again, but they will need to loosen the pump sprocket to realign it, so it's the same amount of work. The expense of the belt itself is tiny compared to the labour, so I wouldn't argue about it.

3) could we undo the cam sprocket and pump sprocket to releave the tension? then do the timing.

Undo the cam sprocket without all the locking hardware in place and you will disturb the timing, more than it is already, as the cam will shift, driven by the valve springs.

i dont want to spend another £300 having the belt re-done at another dealer.

Changing the belt again won't help, you need the pump timing redone.

i was having this one changed because the previous owner had it done by a back street garage which didnt replace all the cam belt rollers, and one of them was rusty and picking up black off the belt!!!

The idlers aren't usually changed, I don't think, unless you ask them to.

apparentley the kit from VAG at least, includes the tensioner and idlers, i received a big bag of stuff when they finished.

if the belt is over tensioned, as my ex-VAG friends suggest, will it shorten its service life?

 

[Muttley]

cypher007 wrote

if the belt is over tensioned, as my ex-VAG friends suggest, will it shorten its service life

If the proper procedure has been followed the tension will have been set correctly by the adjustment of the tensioning roller. It should be easy to check - the markers should line up.

I can't say what the effects of overtightening the toothed belt tensioner would be. I doubt that they would be good, though.

 

[techie]

The belt can be retensioned and the pump timing adjusted just with the top cover off no need to strip the whole lot down.

Personally I dont remove the cam cover, I mark the cam sprocket and pin the pump, use the flywheel mark for the crank. The tensioner is very simple to set to the correct mark then I warm her up and check the timing dynamically. Job done.