Hi all,

 

Just after a bit of advice really.

I recently had my 2016 2.0 TSI VRS booked in for cam chain change. The garage who did this also advised they replaced all associated parts (so cam magnets, oil control valves etc) however on the invoice I can see that the crank pulley bolt wasn't replaced. I've managed to get my phone camera down and can confirm it hasn't been replaced.

 

I have reached out to the garage asking if it was replaced and if not if it is something they would do for me (stating that in the workshop manual it states to replace if removed) however they are not responding to emails now or answering my calls.

 

Does anyone have experience enough to say that this has to be replaced or if it just recommended? The cost of the bolt itself is around £6 so considering I just paid under 2k for the work I am a bit upset they didn't either just replace the bolt or at least ask if I wanted it replacing.

Perhaps it was not necessary to remove the crankshaft sprocket - does the manual specify that the sprocket needs to be removed to replace the cam chain?

Hi, it's not the sprocket as such it's the crank pulley (vibration damper) and the bolt which holds this onto the crankshaft sprocket and crank, so it needed to be removed in order to get the pulley off to be able to remove the lower timing cover. 

What torque plus angle does the manual specify, something quite extreme I'd expect?

Brave to reuse it, if done up again to full spec.

Just now, Breezy_Pete said:

What torque plus angle does the manual specify, something quite extreme I'd expect?

Brave to reuse it, if done up again to full spec.

150nm and +90degrees

Not as extreme as one I did recently. 150Nm plus 180°, on a 9n Polo, took a hell of a lot of doing.

Is it a garage you hope to use again, and have history with? They won't enjoy being told the job hasn't been done right, obviously,  but if they know you, and are a bit grown up, they ought to at least discuss it.

17 minutes ago, Breezy_Pete said:

Not as extreme as one I did recently. 150Nm plus 180°, on a 9n Polo, took a hell of a lot of doing.

Is it a garage you hope to use again, and have history with? They won't enjoy being told the job hasn't been done right, obviously,  but if they know you, and are a bit grown up, they ought to at least discuss it.

First time I have used the garage to be honest. I got a few quotes from different garages and these came out on the slightly higher side. I would like to use them again, however I asked them what I believe to be an appropriate enough question if they could confirm if the crank pulley bolt was replaced but didn't get an answer from email. I then tried to call but noone responded, managed to get through to someone in the end who advised they would ask the technician and get back to me but didn't hear anything else. I then sent another email just saying if the bolt wasn't replaced is it something they would do for me (I would even pay the cost) but again haven't had a response.

 

I'm not trying to say they did the job wrong, just if they responded saying something like "it's not something we have replaced before and haven't had any issues" then that's fine with me. I don't have any experience with these engines but I do worry and rely on the vehicle to be able to see my son, so I would rather try and make sure everything is right as such.

Edited 21 January, 20251 yr by s88urd

I bet the bolt didn't come in the kit they bought, (it wasn't in the genuine VW kit I bought for the 9n Polo) and they interpreted that to mean it was OK for it to be re-used.

Hard to say for certain that it'll be fine; if it was going to break it would probably have done so during tightening.

Bigger risk is that it wasn't done up tight enough, and might subsequently loosen, but it doesn't sound like you'll get an honest answer, if any, to what spec and tooling was used to tighten it.

If it's something that's going to cause you ongoing anxiety, I'd suggest getting another garage to quote for replacing it.

Cheers Breezy, I'll give them a couple more days to reply then I'll go down the route of another garage. I've already been quoted £5 for the bolt and half hours labour.

All the parts on the invoice are listed separately so not sure if they bought a kit or just all the parts individually.

Everything else seems spot on though, all I'm really after is a reply of "yes we can do it for you" or "no sorry we won't" so I know where I stand

There is a lot of unsubstantiated pseudo science trotted out about stretch bolts with the aim of selling parts at inflated prices.

 

They are tightened to within the elastic limit but not to yield, if that were the case they would neck and either break while being  tightened or from the additional service load.

 

You can tighten and retighten a fastener within its elastic limit infinitely, it will always return to its original length when the load is removed, waisted bolts are used so that precise torque-tension can be achieved with a given torque + angular rotation.

 

It started 43 + years ago when Ford started invoicing for sump plugs on CVH engines claiming that the threads were stretched on the old ones, an M20 thread going into an aluminium sump 😄

 

As long as the crank pulley bolt was correctly tightened I would not be concerned.

 

If you want to observe what really needs to be replaced and what doesn't watch the works race and rally teams when they do major repairs between stages or races, see what they replace other than the failed component.

12 hours ago, J.R. said:

There is a lot of unsubstantiated pseudo science trotted out about stretch bolts with the aim of selling parts at inflated prices.

Sure, but there is a reason why VAG state that some bolts are one-time use only.  I'm not sure if this bolt is one-time use or not, but OP seems to suggest that he is concerned about this issue.

It comes down to risk - ultimately, if the OP wants piece of mind, then they can request that the bolt be replaced.

1 hour ago, varaderoguy said:

there is a reason why VAG state that some bolts are one-time use only

 

13 hours ago, J.R. said:

the aim of selling parts at inflated prices.

 

Agreed neither of us know what the official line is regarding this bolt and that the OP will choose to do whatever gives him piece of mind.

Still waiting for the original garage to get back to me with regards to if this is something they will sort out for me.

The workshop manual states to replace/renew the bolt, but as you said whether this is actually required or not is a different question. For the price of a £4 bolt I would rather just get it replaced for piece of mind.

I have talked with two garages about these bolts that VAG suggests to replace anytime you even look at them for too long. Their opinion is to replace these bolts maybe every other or every third time. Assuming nothing seems to be wrong with the bolts.  "And no problems whatsoever"

Ok so spoke to the garage who have informed me the bolt was replaced, however I'm not convinced.

They took a picture showing an oil leak from the cam cover before doing any work in which you can see the bolt (need to zoom in) I took a video on my phone and freezed the frame showing the bolt and it's clear markings on the bolt (specifically a small rust spot is the same)

 

The video has the flash on my phone and is very close to the bolt whence the slight colour difference 

 

What do you all think?

Same bolt, fibbing garage. 

This will be an interesting conversation with them...

I'm not sure there's much to be gained by any further interaction with them, to be honest.

10 minutes ago, Breezy_Pete said:

I'm not sure there's much to be gained by any further interaction with them, to be honest.

I just want it replacing really, I'm worried if I take it somewhere else to be done and I have issues down the line or the bolt snaps then they will want to wash their hands of it

Right, I have spoken to them and they insisted the bolt was changed.

I got asked "what is your worry" and was also advised there is "no chance" of the bolt coming out as they used loctite on it also and they had "done hundreds of these jobs"

When I mentioned the photos they said they would look into it and get back to me.

Just had an email advising they are willing to fit 'another' bolt

 

1 hour ago, s88urd said:

Just had an email advising they are willing to fit 'another' bolt

Sounds like an admission without admitting it ❓

Loctite isn't required or specified.

Either accept that it probably will be fine, or go elsewhere.

 

1 minute ago, Breezy_Pete said:

Loctite isn't required or specified.

Either accept that it probably will be fine, or go elsewhere.

 

Just going to let them replace it as they have done all the other work.

Dont really want to be in a situation where if something goes wrong any warranty gets rejected as someone else has worked on it.

Be careful what you wish for.

 

After being so dogmatic with them, questioning their honesty (I'm sure you are correct) they may well not use their traditional Loctite when replacing the bolt because you are a customer who wants things done by the book and coincidentally their torque wrench may malfunction when they tighten the new bolt.

 

Having seen the catastrophic results of incorrectly tightened crankshaft pulley bolts too many times I would not wish that on you, I wholeheartedly agree with Petes preceeding posting.

Asked them to check the plugs too before they did the chain work and they reported "all even in colour and condition"