Hi Guys, I'm a newbie and am seekingr some advice please. 

My Son has an A5 Sportback 2018 - 190BHP, 37k miles. A few weeks ago, the crankshaft pulley shattered whilst he was driving it. The independent garage undertaking the repair have replaced the crankshaft pulley and the 'Tensioner' as that was fu**ed as well. The mechanic took it for a test drive yesterday and almost the same thing happened again. The crankshaft pulley came off altogether, but hasn't shattered. 

The car is not back to the garage yet, so he's not been able to do another investigation.

Does anyone have any experience of this or any idea what may be causing this issue?

Your help would be gratefully received.

Thanks Guys,

Barry Forster

 

Hi Guys, I'm a newbie [A4 Avant 2019 190BHP] and am seeking some advice please. 

My Son has an A5 Sportback 2018 - 190BHP, 37k miles. A few weeks ago, the crankshaft pulley shattered whilst he was driving it. The independent garage undertaking the repair have replaced the crankshaft pulley and the 'Tensioner' as that was fu**ed as well. The mechanic took it for a test drive yesterday and almost the same thing happened again. The crankshaft pulley came off altogether, but hasn't shattered. 

The car is not back to the garage yet, so he's not been able to do another investigation.

Does anyone have any experience of this or any idea what may be causing this issue?

Your help would be gratefully received.

Thanks Guys,

Barry Forster

It's hard to believe one pulley disintegrated; for two to fail suggests an inherent fault in the mounting, but quite what the fault could be I have no idea.

2 hours ago, Barry Forster said:

 

Hi Guys, I'm a newbie [A4 Avant 2019 190BHP] and am seeking some advice please. 

My Son has an A5 Sportback 2018 - 190BHP, 37k miles. A few weeks ago, the crankshaft pulley shattered whilst he was driving it. The independent garage undertaking the repair have replaced the crankshaft pulley and the 'Tensioner' as that was fu**ed as well. The mechanic took it for a test drive yesterday and almost the same thing happened again. The crankshaft pulley came off altogether, but hasn't shattered. 

The car is not back to the garage yet, so he's not been able to do another investigation.

Does anyone have any experience of this or any idea what may be causing this issue?

Your help would be gratefully received.

Thanks Guys,

Barry Forster

Hi anybody checked the end float on the crankshaft.

Steve

Hi Steve, thank you for your thought. I'll suggest that to the Engineer tomorrow.

Barry.

Must be something else more series at play here, one failing is rare, another becoming detached so quickly raises questions on installation process. Back to basics first, check for end float as Steven Y says, check for play in other pulleys while Belt is removed. Have seen the alternator pulley failing due to the internal clutch on Vag cars and overheat the belt but not leading to a crank pulley leaving the chat 

Thank you Matt for your thoughts and comments - it is a mystery.I will pass them onto the mechanic.

The mechanic is veering towards an engine issue, crankshaft out of line or something like that I think.

Be interesting to run the car with no pulley and monitor the crank shaft rotation. Be interesting to know the solution when complete so please report back and even if the problem persists reposting with what was tried allows us members to try to help further

Hi Sid2020, many thanks for your post, thoughts and comments. I will pass your idea to the mechanic and I will let you know if and when the issue is resolved,

I am thinking of taking the car to an Audi Main Dealer.

Barry

9 hours ago, Barry Forster said:

Hi Sid2020, many thanks for your post, thoughts and comments. I will pass your idea to the mechanic and I will let you know if and when the issue is resolved,

I am thinking of taking the car to an Audi Main Dealer.

Barry

Hi sorry but are you INSANE they will invent a raft of possibilities ending in 

Sorry mate you need a new engine £7000 please plus fitting.

Steve

The trouble is that I'm not confident about the independent who has the car at the moment. I've probably racked up £1000 already. I was gonna start with the question - 'Have you had this issue before'?

I’m not confident in your independent either, for a crank pulley to just come off id say it wasn’t put on correctly, it also just wouldn’t drop off it would come off with a lot of momentum and possibly damage other items. And even if the crank was slapping around in the casing i would expect it to chew up the belt first and the knocking would be of more concern. 

2 hours ago, Barry Forster said:

The trouble is that I'm not confident about the independent who has the car at the moment. 

We tend to favour independents over main dealers, but that's not to say all are better. Does your man specialise in VAG vehicles, or is he more a "all makes, all ages" generalist?

Can you post photos of the failed pulleys or their remnants?

Thank you Matt for your thoughts and comments - it is a mystery.I will pass them onto the mechanic.

The mechanic is veering towards an engine issue, crankshaft out of line or something like that I think.

He does mainly VW and Audi but does some independents as well. I'll try and get the old pulley and tensioner next time I go. 

OK Guys, it's been a long time but finally the A5 has been sorted and I've got to the bottom of what happened and how.

The original crankshaft pulley failed - a flaw in the casting meant that the boss was still bolted to the crankshaft, but the pulley itself sheared away - which enabled the car to be driven.

However, the replacement pully coming off wasn't a design flaw, it was a case of the sprocket being incorrectly fitted and not aligned with the crankshaft - there are 'mating marks' on the pulley and crankshaft that, if not aligned correctly, will result in the pulley coming off again. But this time, it did serious damage. The head had to be removed, reground, and 8 new valves fitted, plus all the necessary gaskets etc. 

So as a result, the A5 is now purring very nicely.

The mechanic effectively accepted responsibility for the second failure and associated works, without any pressure from me I must add, and asked whether I would be willing to pay for the parts and no labour costs. That came to about £1300:00, which, in the circumstances, wasn't unreasonable.

Thank you to all who offered help and advice.

Best regards, 

Barry.

It’s fixed and your happy, garage cocked up and owned up

Yep! And no arguments either.

Thanks for the update Barry. Glad the problem is now solved and that your mechanic owned up. In your position I too would have paid for the new parts, even if not strictly necessary, as a gesture to him.

Thanks Cliff -  we parted on good terms as well.

Which is more than your pulley did with your engine Barry! 

😂😂😂