Cambelts -- A Warning

[skodaw]

Hi Guy's,just thought I would bring the importance of cambelt replacement's to everyone's attention.

I am talking in particular to al 1.8T,4x4 & vRS owners,although it's just as important on other models too.

As some will know I work at an Audi Centre,and we are seeing more & more premature cambelt failures-some due to neglect and others seamingly without explanation.....

Please PLEASE make sure you know when your cambelt change is due - and even think about early change especialy those who've had "Performance Enhancing" done.

The interval varies between model,but I would strongly recomend anyone to change belt's at 60,000 miles - not the 80,000 or 120,000 that some models go to -- the cost invovled when they go is huge - you're looking at £1,000 plus for a head - and they do reck heads when they go.

I know that this thread should strictly be in My Maintenance but I thought it important enough to leave in general - I'm sure our moderators will judge accordingly.

1 last point -- change intervals are sometimes quoted in KM's -- be aware - 120,000 KM's = 74,000 Miles NOT 80,000 miles,likewise 180,000 KM's = 111,000 Miles.

You HAVE been warned.....

[KLB]

I know it's the best part of 20 years ago now - but the recommendation for my Fiat 124 was to change the cambelt at 36,000 miles, never mind 60,000.

And yes - thay can make an awful mess when they break (not my car, fortunately) - wrecked pistons, bent con rods, bent valves & valve gear, scored cylinders, and so on....

[skodaw]

Yeah...worse case we have at moment - A3 1.8Tq - list of damage as follows.

1.All 20 valves buried into cyl head OUCH!!
2.Cylinder Head u/s - unable to remove embedded valves -
3.Cams - both snapped
4.All 4 pistons badly marked by valve impact-inc very small peice missing from 2
5.Cylinder bores slightly marked.
6.Big End bearings marked by impact.

And the best thing - "I was sitting at the traffice lights when it happened" - from customer.
"Liar,Liar pant's so on fire the rest of the world is burning....." - my thought when he said it..

[DGW]

...and the bill is likely to be?

[Quinten]

I always thought the 120K miles (iirc) was a bit optimistic to say the least. I'd planned to have it changed at 60K as was the case on my Laguna.

[jawsnpaws]

Is this type of replacement a warranty isssue if the car is under 3 years old ?

Seems like at three years , many who buy a car new , either exchange at that point or , if it has been a " good " car decide that they want to make up for the initial depreciation and keep it for another 3 years .

For the latter , replacement of the cambelt , is probably most wise at the three year mark ..... is it a relatively simple exercise and should there been any other work carried out whilst part of the engine is dismantled for this replacement .... ?

[skodaw]

Cost expected to around £1,900 plus vat.

If the vehicle is under 3 years & 60,000 miles and has been "correctly" serviced then it "MIGHT" be under warranty -- every 20,000 mile service includes(as for Audi) "A visual inspection of the cambelt" now this can only be done by removing the cover - and even then you can see much.

We are finding that the belts strip - the teeth rip off - I have yet to see a belt that has snapped - unless caused by some other defect - oil pressure too high etc(cause vvt gear to over adjust and BANG)

I would strongly suggest 60,000 as a limit - I would also suggest that the water pump be replaced whilst engine is stripped -- I have seen these fail - and if the plastic impeller breaks up it can be a right bug*#r to remove all the peices.

It's not a major job - takes approx 2-2.5 hours - although I would say def NOT a D.I.Y job.
the parts required :
1.Cambelt
2.cambelt tensioner pulley
3.cambelt damper
4.Water pump (advisory)

Certainly a lot less hassle and cost to replace belt early than wait for the BANG.

P.S forgot to mention - the cost I advised at the top does not include the cost of pistons/big end bearing/oil pump and a few other bits that the car really should have.....but the lease co will not pay for - I should also point out that they don't want us to do anything with the bores - which are slightly marked..."Because it will be sold soon....."god help the next owner

[flyingscot]

Originally posted by skodaw in this post
Cost expected to around £1,900 plus vat.

£2200 yikes! I wouldn't like that to happen to my car! I know that cambelt damage can occur on some cars even more prematurely than others. A Peugoet 306 I heard about had one go at 46,000 miles. All be it 4 years old, but you'd still expect a little longer. His cost was similar bujt luckily Peugeot and the garage helped out with a deduction in labour rate and a token sum off from Peugeot. If you don't do a big milage you might be advised to do it after say 4, 5 years rather than waiting!

[jawsnpaws]

scaaarrry !!!

Think that next year - better the devil you know - will prevail !!

thanx for the info .......

maybe you should have your own forum for other nuggets of information that you could pass on .

many many thanks .

[spc]

It seems such a shame that the majority of cars now have belts instead of chains driving the camshaft. Anyone who has ever worked with a chain drive will know that they last longer and although they do wear the 'catastophic' failure is far less likely an outcome than it is with belts. I'm sure belt-vs-chain is driven by cost, but the lower manufacturing cost tends to shift a higher balance of maitenance cost to the vehicle owner.

Also, I'm sure I've heard that some engines are designed such that there is no interference twixt valves and pistons even in the even of a belt failure leaving the cam and crank totaly out of sync. Anyone else heard that?

[Kentish]

Some very wise words coming forward here, but also bear in mind the cost to replace the cambelt , and all the followers and tensioners , of my VW Transporter Tdi was £900, and that at a VW dealer....also very ouch! (and this was on top of a bloody service)

I think my motto is dont drive the damned things at all

Cheers

[flyingscot]

Originally posted by spc in this post
It seems such a shame that the majority of cars now have belts instead of chains driving the camshaft. Anyone who has ever worked with a chain drive will know that they last longer and although they do wear the 'catastophic' failure is far less likely an outcome than it is with belts. I'm sure belt-vs-chain is driven by cost, but the lower manufacturing cost tends to shift a higher balance of maitenance cost to the vehicle owner.

Stewart Grand Prix used to use the Cosworth V10 engine in 1997 that was chain driven. It was the only chain driven engine in the field and was as a result the most unreliable engine in Formula 1!

[spc]

But haven't Jags managed OK on chains for a year or two?

[otheos]

So very true!! I had my cam chain snap at 118,000Km, when it was due to be changed at 110,000km. I neglected it (and thought it could go another 10,000Km) and it went.

And the best thing - "I was sitting at the traffice lights when it happened" - from customer. "Liar,Liar pant's so on fire the rest of the world is burning....." - my thought when he said it..

Not necessarily. Mine snapped in idle and had similar damage. However the fact that ALL valves were bad rather points to high revving during snapping.

Still I had to pay £2000 when a new engine was double that. The worse bit was that 2 months after that (+ new exhaust another £460) my car was stollen (and the insurance company dismissed my expenses in a heartbeat as expected )

[Dutch4x4]

Originally posted by Quinten in this post
I always thought the 120K miles (iirc) was a bit optimistic to say the least. I'd planned to have it changed at 60K as was the case on my Laguna.

That has always been my understanding too - with 100,000 kms the magic figure usually quoted to me, no matter what make and type of car.

So 60k miles seems very appropriate to me in any case.

Although I have swapped the last few cars long before I reached that...

[Quinten]

Come to think of this (and to better my knowledge of car technics), why does a snapped cambelt cause so much damage?

[mellowyellow]

Originally posted by skodaw in this post
If the vehicle is under 3 years & 60,000 miles and has been "correctly" serviced then it "MIGHT" be under warranty --

Dave , I would have thought that it SHOULD be under warranty .

If the manufacturers guidelines are that the cambelt should be changed at 80,000 miles and you have followed the service schedule , if the cambelt breaks before 60,000 miles then I would assume it all should be done under warranty .

[big k]

Originally posted by spc in this post
It seems such a shame that the majority of cars now have belts instead of chains driving the camshaft. Anyone who has ever worked with a chain drive will know that they last longer and although they do wear the 'catastophic' failure is far less likely an outcome than it is with belts. I'm sure belt-vs-chain is driven by cost, but the lower manufacturing cost tends to shift a higher balance of maitenance cost to the vehicle owner.

in the 15+ years i've been working on cars i've ever only changed one cam chain kit (this was purely because it was noisey) i now service a fleet of taxi's with 200,000+ miles on them they come in every 60k on the dot not one problem hence to say i've had a fabia tdi loose plastic surround on tensioner and damage engine severly.

[skodaw]

As for the warranty question - it's a grey area,if it's under warranty-Audi(I can only speak on them) will usually pay by one means or another(factory warrantyplus uk top up) - but if the car is over 3 years old ie out of warranty - then it's purely goodwill only....case in point- car recovered to us today S3 3yrs old last march - 46,000 miles -- Audi will give 70% parts discount - no labour contribution,even though belt is not supposed to be changed untill 111,000 miles !!

As for why so much damage is done when cambelt fails - cambelt's main role is to keep the top end)ie camshaft) and bottom end(ie pistons) turning in time with each other-as pistons go down,so do valves and vice-versa(hence often called timing belt)this allows for much closer tolerance,for less space and more efficient combustion and increase power - if the belt breaks or strips then this allows pistons to rise whilst valves stay open,and in the case of 1.8T engines - go BANG.

A lot of makers swapped to belts due to chains being noisey,however there is a move back toward chain drive -- all "NEW" engines from Audi are apparently going to be Chain-case in point new S4 - although they are doing it to save space(approx45mm) rather than added reliability(apparently)

[Quinten]

Thanks Dave, along with a read over at howstuffworks.com I finally grasp the concept Should have gone there first I guess...

[mellowyellow]

The trouble with cambelts is that manufacturers set the replacement intervals , and if they have some break before the recommended intervals , they then change the replacement intervals ..................as with Vauxhall in the last year , on some of their vehicles they have halved the replacement mileage

[Dutch4x4]

Originally posted by skodaw in this post
but if the car is over 3 years old ie out of warranty - then it's purely goodwill only....case in point- car recovered to us today S3 3yrs old last march - 46,000 miles -- Audi will give 70% parts discount - no labour contribution,even though belt is not supposed to be changed untill 111,000 miles !!

I'd have you in court for that - and I'd win, slamming EU consumer law right in your face...

[otheos]

I'd have you in court for that - and I'd win, slamming EU consumer law right in your face...

I second that. For £2K, better have the lawyers take it than Skoda/Audi/VW/Seat. After all it should last. Not our fault.

[skodaw]

That's true - at one time it was easy DIESEL = 60,000 PETROL = 80,000,now some Diesel are 80,000 and some Petrol(RS4) are 40,000 and some are 74,000,some are 111,000 some are never ????(A3/A4 1,6).

With the new variable servicing it's making things even harder - case in point Audi Allroad 2.5 TDi quattro came in week b4 last - 84,000 miles - belt due at 74,000 - VERY lucky - guy lives 400 miles from us - never been to us before or likely to again - was in area on business - we had to lend him a car for a week (&2,300 miles) so we could do belt - if we had let him go with out doing it - we would have been liable -- even though it's his responsibility to make sure car is serviced on time and correctly...and he wasn't a bit gratefull that we actually registered a car for him to use(A6 2.5 Avant) because "Its not an Allroad" !!!!
There is a very true saying in the motor trade -- Without customers this job would be grate!

although before anyone points it out - I will admit that without customers we would exist,and it has to be said that I have more good customers than bad -- I even count some of them as personal friend's.

but another trade saying -- "Miracles we can do -- the impossible takes longer...."

[DGW]

Octavia toothed belt replacement intervals are:

1.8T petrol engines - 180,000km

TDI and SDI engines (except ALH engine with auto gearbox) - 90,000km

ALH diesel engine with auto gearbox - 60,000km