OT cambelt replacement

In article

you probably will need a new engine, if the belt goes when you are doing
any serious speed. It's not just the garages who recommend replacement,
it's the car manufacturer, too and if you have an MOT you have to sign a
disclaimer that if the belt goes when they rev the engine hard (emission
tests), the garage is not responsible.

--
From KT24

Using a RISC OS computer running v5.18

charles wrote:

I have never signed or even been asked to sign any such disclaimer.
--
Adam

I don't think you have to sign a disclaimer.
there are notices and leaflets at all MOT stations that tell you what may
happen if you have a badly maintained engine and you are deemed to have
accepted the responsibility if you ask for the test.

If the belt breaks on many engines the pistons will hit the valves.
I had a tensioner break on a triumph herald and that had a recon engine
fitted as a lot of bits were bent.

On Tue, 17 Apr 2012 04:50:04 -0700, kent wrote:


For most engines (the only exception I can recall was the FIAT "FIRE"
engine, for some reason) a cambelt breaking is the ultimate catastrophic
failure. The valves will freeze in position, whilst the pistons (usually
carried by the inertia of the car via the gearbox) will hit them full on.
Although failure usually happens when starting the car (when resistance
is highest, and teeth are most likely to shear) which might mean you get
away with having the valves replaced.

It's certainly one of those "you REALLY need to know what you are doing"
DIY jobs. Quite apart from the fact that most cambelts are buried into a
very tight space, getting the new belt wrong by one tooth can mean
disaster.

If you are doing it yourself, make sure you VERY CAREFULLY try and turn
the engine manually through 2 cycles, to ensure everything is in line,
and you aren't going to hear a dull clunk when you go to start the car.

No, I'm not intending to do it myself.  
I do know a lot of awful things can result.  What I really want to know is the
likelihood of it actually occurring.  Has it happened to any readers here or to
anyone they know?  Have any of you ignored the garage's recommendation and
suffered the failure?

On 17/04/2012 13:19, kent wrote:

likelihood of it actually occurring.  Has it happened to any readers here or to
anyone they know?  Have any of you ignored the garage's recommendation and
suffered the failure?

Happened to me on an 05 Pug Partner van. Turned out to be ex-rental, and
probably never seen a service bay in its life....

Belt was due to be changed at 80k - snapped @ 78k, wrecked the head but
the garage put a recycled one on for the cost of the labour...

Yes - the belts do go - and they can make a complete & expensive mess of
an engine.... but, if you're feeling lucky, why not ignore the
manufacturer's advice....? <grin>

Adrian

In message


Happened to me in a Rover 216 (I think) about 20 years ago.  Fairly
catastrophic, but I don't know the actual cost, as it was a company car
- luckily!  Certainly not cheap.

--
Graeme

kent wrote:

likelihood of it actually occurring.  Has it happened to any readers here or to
anyone they know?  Have any of you ignored the garage's recommendation and
suffered the failure?
yes, twice


--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.

wrote:


likelihood of it actually occurring.  

ignored the garage's recommendation and suffered the failure?

2 years 3 weeks and a few days into a 3 year warranty and before it
was due to be replaced the elastic on a 3l Alfa V6 gave way at 80MPH
on the M25 (it was very early in the morning) and everything went very
very quiet.  Fortunately Alfa Romeo didn't so much as blink but simply
replaced the engine.

On 17/04/2012 13:19, kent wrote:

likelihood of it actually occurring.  Has it happened to any readers here or to
anyone they know?  Have any of you ignored the garage's recommendation and
suffered the failure?

I've 'repaired' an Audi 2.5L Diesel after a cambelt failure - no
noticeable damage to pistons, but valves, cams, cam carriers etc all
seriously damaged. Replaced the engine with a s/h unit.

Yes they do fail - unless you're happy to scrap the car when it goes, I
would pay up now - the repair cost would probably exceed the car's value.

On 17/04/12 13:19, kent wrote:

 > What I really want to know is the likelihood of it actually occurring.
 > Has it happened to any readers here or to anyone they know?  Have any of
 > you ignored the garage's recommendation and suffered the failure?

I know of someone who had it happen at 80mph on the M6. Was a second hand
Primera still under warranty, fortunately. Needed a completely new engine
(and he was fortunate not to crash the car when it happened!)

And next time try keeping your lines to a sensible length. I had to rearrange
yours just to be able to post this reply (the news server I use doesn't allow
over-long lines).

After serious thinking kent wrote :

I have not had one go, but I have heard of quite a few wrecked engines
from them going.

The manufacturer does some calculations based upon mean time to
failure, then allows a fairly safe distance between that and a
recommended change mileage. The was a Ford which had lots of breakages
and still within the period before the belt was due for change.

Personally I don't take the risk - if an engine is on borrowed time and
there is no receipt for it having been changed, then I change them
ASAP.

The risk is yours, your decision entirely. For every mile you do beyond
the recommended change mileage, the more likely it is to break.

--
Regards,
        Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

En el artculo <21191399.44.1334665193257.JavaMail.geo-discussion-


What's wrong with uk.rec.cars.maintenance?

--
 (\_/)
(='.'=)
(")_(")

wrote:


I think that's because the FIRE engine is not an interference engine.

That means nothing smashes into anything else if the cam belt breaks
(just like the old Ford Pinto 2L lump). ;-)

Cheers, T i m

On 17/04/2012 12:50, kent wrote:

strongly recommending that the cam belt be replaced (it's the original).  Now I
know that if it does go it will cause a lot of engine damage, but how likely is
that really to happen?  Is it a widespread problem or do garages just use horror
stories to get customers to part with their cash?

SWMBO had it happen once ages ago in our Ford Sierra; think she was
doing zero mph or idling or something at the time; anyway, there was no
damage done to the engine and we were told we were damned lucky.

David

On Tue, 17 Apr 2012 13:14:57 +0100, Lobster


strongly recommending that the cam belt be replaced (it's the original).  Now I
know that if it does go it will cause a lot of engine damage, but how likely is
that really to happen?  Is it a widespread problem or do garages just use horror
stories to get customers to part with their cash?

I had one go in my 2L Pinto powered Sierra and nothing bad happened at
all (because it was a 'safe' engine). ;-)

1 hour after that I'd been towed in to my mates garage, had all the
required bits off, the new belt was delivered and I'd fitted it and
driven home. Total cost about 12 quid and some beers for my mate. ;-)

Cheers, T i m

On 17/04/2012 22:23, T i m wrote:

strongly recommending that the cam belt be replaced (it's the original).  Now I
know that if it does go it will cause a lot of engine damage, but how likely is
that really to happen?  Is it a widespread problem or do garages just use horror
stories to get customers to part with their cash?

There are even diesels, with inherent interference between valve and
piston where damage is generally minimal.  Vauxhalls with rockers will
generally bend a rocker, the Ford 2.5DI will bend push rods and break
rockers, which end up to be cheaper than a new set of belts!!

On Tuesday, April 17, 2012 12:50:04 PM UTC+1, kent wrote:


  I knew a mechanic who knew the costs by heart for the models he worked on=
, so it wasn't infrequent. They were some expensive high-performance carsd,=
 I don't recall the make, Porsch, Ferrari or such like, so probably more li=
kely and more damage if it does happen.

Our 2003 Zafira has done 90,000 miles and not surprisingly the garage is
strongly recommending that the cam belt be replaced (it's the original).
Now I know that if it does go it will cause a lot of engine damage, but how
likely is that really to happen?  Is it a widespread problem or do garages
just use horror stories to get customers to part with their cash?
Anyone any experience of this?  Thanks.

I suggest you get it done ASAP. I had one go on an XR2 doing ~30mph, it just
lost drive and cost me a bomb. I forget the details.
For 30 there's always this -
http://www.timing-belt-failure-insurance.co.uk /