Any mechanics in here? Help please Audi A6

Flashheart · 29 Oct 2019 at 17:25

Hey dudes.

I need some advise please. I have a 2014 A6 ultra, that up until a week ago has ran without issue. I've had the car about 8 months or so and as she has just gone past the 4 years and 120k mark I booked a mobile mechanic to do my cambelt / water pump change.

The work was completed last wednesday. He tested it and all seemed well. I went to work thursday morning, my journey is approximately 7 miles and there were no issues. Pulling out of the car park at the end of the day I had an engine management light on the dash.

I gingerly drove her straight home and plugged my gismo in to check the fault out. Initially I had a P0011 (cam timing fault). Cleared that and had flashing glow plug light and a P0016 fault also cam timing related.

He has come back out today and essentially told me that he thinks the cams may be bent, but confirmed to me that he has checked over his work and it is spotless, so the fault must have existed prior and the changing of the belt may have disturbed things. He has checked / replaced the cam sensor and it made no difference.

I plan to get in touch with the credit card to get my money back, as I can't see that what he is saying makes any sense.

Are there any mechanics in here that can confirm that what he is saying could be plausable?

Reccomendations please?

Thanks in advance

SonicSW20 · 29 Oct 2019 at 17:33

Sounds like porkies to me. I've never come across a "bent" camshaft.

Nasher · 29 Oct 2019 at 17:39

Isn't there a pretty common cam chain problem on these engines? If it's that definitely don't drive it or you'll need a new engine

Flashheart · 29 Oct 2019 at 17:48

Its a cambelt, I'm worried that any damage has already been done to be honest

jsmoke · 29 Oct 2019 at 17:55

Sounds like he hadn't done the job properly. I guess it's tougher working out in the street. Take it to a garage, get a diagnosis then decide if you want to ask for a refund.

[TW]Fox · 29 Oct 2019 at 17:59

Nasher said:
Isn't there a pretty common cam chain problem on these engines?

He even says it's a belt in the OP :rolleyes:

Flashheart · 29 Oct 2019 at 18:02

jsmoke said:
Sounds like he hadn't done the job properly. I guess it's tougher working out in the street. Take it to a garage, get a diagnosis then decide if you want to ask for a refund.

Im thinking this, but what happens if it's already done the damage?

Small claims?!?

jsmoke · 29 Oct 2019 at 18:04

He should be insured.

Dogbreath · 29 Oct 2019 at 18:32

Camshafts simply don't "bend" unless a catastrophic failure has occurred. It's possible you have been unlucky enough to suffer a fault with the VVT system, are you getting any other symptoms like extended crank time?

viper_2003 · 29 Oct 2019 at 20:58

Forgive the obvious response but could the timing ‘just’ be a tooth out?

Flashheart · 29 Oct 2019 at 22:53

He reckons not. The mechanic told me that if it were it wouldnt run.

I'm pretty handy, but never had experience with cambelt as I changed car every 12 months

eviled · 29 Oct 2019 at 23:31

Never worked on a diesel VAG but it sounds like the timing hasn’t been set properly.

Drive it to a garage to sort it

You’ve already driven it and it hasn’t exploded so it likely isn’t far off. Often there’s a procedure for resetting the timing properly, more than just belt on, belt off. Or like has been said it’s a tooth out, or it’s times to the wrong marking on the crank pulley.

Camshafts don’t bend, they are held down by 5 caps, they snap but then it wouldn’t run if that had happened

Gaygle · 30 Oct 2019 at 08:53

My guess is that he's knocked the timing out. Go to a proper garage and have it fixed, then ask him to pay the bill.

vanpeebles · 30 Oct 2019 at 09:16

I bet it's a tooth out as well.

Armageus · 30 Oct 2019 at 09:26

Flashheart said:
He reckons not. The mechanic told me that if it were it wouldnt run.

If only a tooth out it will likely run, just badly.

Had a Cooper S that the timing had jumped a tooth due to the tensioner fault - for the most part it ran fine, but would occasionally stutter badly. The ECU/VVT does a fair job of compensating, so it was quite hard to diagnose.

Terminal_Boy · 30 Oct 2019 at 09:38

Car run flawlessly before cambelt/water pump change, so OP mobile mechanic messed something up. Get the car to an Audi specialist ASAP.

I’ve seen bent camshafts on two occasions, once where a bike at the IoM TT had hit the corner of a stone wall at over 100mph (rider was fine as he bailed out early) and once on a top fuel dragster which had suffered a catastrophic supercharger explosion.

Camshafts don’t bend in normal use. Even if the cambelt snaps and the valves hit the pistons, the camshaft/s aren’t damaged.

Entai · 30 Oct 2019 at 16:51

Terminal_Boy said:
Car run flawlessly before cambelt/water pump change, so OP mobile mechanic messed something up. Get the car to an Audi specialist ASAP.

I’ve seen bent camshafts on two occasions, once where a bike at the IoM TT had hit the corner of a stone wall at over 100mph (rider was fine as he bailed out early) and once on a top fuel dragster which had suffered a catastrophic supercharger explosion.

Camshafts don’t bend in normal use. Even if the cambelt snaps and the valves hit the pistons, the camshaft/s aren’t damaged.

That's not strictly true in many occasions now a days.

Camshafts have always been made from a solid piece of metal usually cast iron. This has been strong and reliable solution for many years.

Modern camshafts however are made of thin wall tubular steel with the camshaft lobes pressed, induction shrink fitted or broached onto a hollow shaft.

This method of construction is very light weight and therefore helps the manufacturer achieve more economic and versatile production, power/performance & better fuel economy results.

A camshaft manufactured in this way is known as an “Assembled Camshaft”.

A common problem has come to light over recent years with the introduction of these light weight camshafts. If an engine suffers timing belt or chain failure and the piston crown comes into contact with the valves in the cylinder head a chain reaction is set off through the valve train which can shift the lobes on the shaft and alter the phase timing across the whole of the camshaft. This isn't good but even worse this problem is very difficult to identify.

At work we have seen many occasions of this, and even had several such failures when the valves did not hit the pistons at all, but the lobes did move.

Five of such instances were after running some 2.0 VW diesels on the engine dyno at around 3,500 to 4,500 revs for prolonged time.

Terminal_Boy · 30 Oct 2019 at 17:35

Today I Learned : Not all camshafts are created equal.

jpaul · 30 Oct 2019 at 17:47

Entai said:
Five of such instances were after running some 2.0 VW diesels on the engine dyno at around 3,500 to 4,500 revs for prolonged time.

you're not saying they had been chipped though ?