Pigs tails and stop start error after cambelt change.[SOLVED]

[Jonesy123]

Hi all

New to forum but not to VW.
Been restoring classic minis and campers for 30 years (when stuff made sense)

Come a cropper with a new fangled T6. Your knowledge of such things would be appreciated.

Its a 2016 T6. CAAB engine
Run like a dream since I bought it, never failed an MOT (coz I know how to prep for an MOT)...

Recently my pals cambelt went pop...so I thought I would get mine done as im at 100k and ought to have done it by now.
chap I've know for 20 years who's an ex VAG engine guy said he would do it in exchange for me dog sitting and watching his works unit whilst he was away....bargain if you ask me.

Since driving it away yesterday I've had intermittent flashing piggy tails (seems to be most prominent at full operating temp and when under torgue load, so uphill in 3rd or 4th for example....but thats anecdotal...not enough data to quantify that exactly as a trigger.

I've had no power loss, rough idol or limp mode and no issues starting it first time.

Also:
Had "Error: Stop/Start" on dash when stop start button is engaged.

I trust the fella who did the work, he knows his stuff but he's in Español for a fortnight so can't get it back to him.

see images:
the bottom fault code is off a Calista OBD2.
I Dont have a VCDS anymore.

I'm hoping its a sensor, I can't believe he screwed up the timing, hes been transmission and engines for 50 years including 22 years with VAG..... but that doesn't explain the stop start function failure, that also doesn't show on Calista.
could it be a dicky CPU? Might account fir the two separate issues if its electrical.?

Anyway...I throw this into the wider community for input.

Please one request (most humbly).. no Google / copy and paste mechanics, id prefer real experience.

 

[Dundee_Kev]

The fact the fault wasn't there before, I'd hazard a guess that maybe the the belt tension is loose. If the belt was out by a tooth, I'd expect the light to be on from engine start and stay on. The fact it varies, let's me think it could be a tension issue. If he has done the job as per the manual and had the camshaft pulley adjuster bolts slackened, maybe they have been left loose and causing the shaft to shift back and forward.

I would remove the upper timing cover and have a look at the tensioner pulley and see where the pointer is sitting and also look at the camshaft pulley

 

[Jonesy123]

The fact the fault wasn't there before, I'd hazard a guess that maybe the the belt tension is loose. If the belt was out by a tooth, I'd expect the light to be on from engine start and stay on. The fact it varies, let's me think it could be a tension issue. If he has done the job as per the manual and had the camshaft pulley adjuster bolts slackened, maybe they have been left loose and causing the shaft to shift back and forward.

I would remove the upper timing cover and have a look at the tensioner pulley and see where the pointer is sitting and also look at the camshaft pulley

Yeah I was thinking about checking the positioning

Thanks for your help.

 

[Jonesy123]

The fact the fault wasn't there before, I'd hazard a guess that maybe the the belt tension is loose. If the belt was out by a tooth, I'd expect the light to be on from engine start and stay on. The fact it varies, let's me think it could be a tension issue. If he has done the job as per the manual and had the camshaft pulley adjuster bolts slackened, maybe they have been left loose and causing the shaft to shift back and forward.

I would remove the upper timing cover and have a look at the tensioner pulley and see where the pointer is sitting and also look at the camshaft pulley

 

[Dundee_Kev]

It looks slightly tight. You'd need to turn the engine round and see where it averages out at. It will move around to a degree anyway.

 

[Jonesy123]

It looks slightly tight. You'd need to turn the engine round and see where it averages out at. It will move around to a degree anyway.

 

[Jonesy123]

So I've filmed it with the engine running, wiggles a tad but still more or less in the same position.... im sure the pointy bit is meant to be lined up in the middle of that groove?

 

[Dundee_Kev]

im sure the pointy bit is meant to be lined up in the middle of that groove?

Yeah, should be in the middle. As you tighten the tensioner, the pointer will move clockwise, as it slackens it will move anti clockwise.

If your careful. You could give it a little slacken off. 6mm Allen key to hold the tensioner and a 15mm I think for the nut. Keep the Allen key held while you slacken the main tensioner nut. Once it's slackened, then allow the tension off the Allen key untill the pointer lines up and retighten the nut.

You may find when you tighten the main tensioner that the tensioner will move. My guess is that's what happened with the guy that tensioned it. Just repeat the process untill it's spot on. Don't be too worried if it's out a fraction, it will be fine. Make sure to turn the engine a couple of turns and recheck the tensioner position.

Then reset the codes and see what happens. If all good, then great. If not, then the timing will need to be checked properly

 

[Jonesy123]

Yeah, should be in the middle. As you tighten the tensioner, the pointer will move clockwise, as it slackens it will move anti clockwise.

If your careful. You could give it a little slacken off. 6mm Allen key to hold the tensioner and a 15mm I think for the nut. Keep the Allen key held while you slacken the main tensioner nut. Once it's slackened, then allow the tension off the Allen key untill the pointer lines up and retighten the nut.

You may find when you tighten the main tensioner that the tensioner will move. My guess is that's what happened with the guy that tensioned it. Just repeat the process untill it's spot on. Don't be too worried if it's out a fraction, it will be fine. Make sure to turn the engine a couple of turns and recheck the tensioner position.

Then reset the codes and see what happens. If all good, then great. If not, then the timing will need to be checked properly

Mate thankyou.
Its a shame I can't upload the video you could see it in action

 

[Jonesy123]

SOLVED.

So to close this out.
Had it all off again and it seems my pal pegged the cam, the fuel pump but not the crank.
So when he turned the engine over with his knuckle bar, it moved.
Was about half a tooth out.

Reset and refitted the cam belt and errors all gone.