KV6 teenage timing belt exposed at last!

[Typhoon190]

There is no way anyone could guarantee either way regarding the life span of the timing belts.

The 6 years/90 000 miles is a sensible guideline offered by the manufacturer.

They could last longer, they could fail sooner. It's likely that there are many contributing factors to the degradation of the belts.

Car garaged? Motorway miles? Lots of short journeys? Surrounding environmental conditions?

Much like many other parts on the car!

Glad the belts lasted well on your car Simon, and goes to show under certain conditions the belts may well last well beyond the recommended schedule, however it's not a worthwhile risk IMHO.

[gazcon]

Like many of us, I spend more time than I should browsing eBay, Gumtree etc for MG Rovers.

Of the many 75/ZTs I've seen over the years listed as spares or repairs, I don't recall ever seeing a V6 that was killed by the belts / pulleys letting go. Numerous 1.8s killed by HGF, numerous clutch failures etc etc. Very few if any cambelt failures.

Obviously anecdotal, but it seems undeniable that these belts last considerably longer in real world use than the 60,000 miles / 6 years stated.

If V6s gave up the ghost at say 65,000 miles or 7 years, there would not be many left on our roads at all. Most 75/ZTs are firmly in banger territory, and owned by people who would baulk at fitting decent tyres let alone spending £400+ on preventive maintenance.

I bought a V6 estate for my dad 4 years ago, and used the fact that it had no cambelt history to negotiate some money off. It's now 16 years old, has done 90k on what we presume to be the original belt, and as it's a workhorse of little sentimental or economic value if it lets go it let's go and he'll get another one.

Having said all that, if I were to buy a low mileage minter to see me out then I'd get the belts changed for peace of mind.

You pays your money (or not) and you takes your choice.

[gazcon]

Like many of us, I spend more time than I should browsing eBay, Gumtree etc for MG Rovers.

Of the many 75/ZTs I've seen over the years listed as spares or repairs, I don't recall ever seeing a V6 that was killed by the belts / pulleys letting go. Numerous 1.8s killed by HGF, numerous clutch failures etc etc. Very few if any cambelt failures.

Obviously anecdotal, but it seems undeniable that these belts last considerably longer in real world use than the 90,000 miles / 6 years stated.

If V6s gave up the ghost at say 95,000 miles or 7 years, there would not be many left on our roads at all. Most 75/ZTs are firmly in banger territory, and owned by people who would baulk at fitting decent tyres let alone spending £400+ on preventive maintenance.

I bought a V6 estate for my dad 4 years ago, and used the fact that it had no cambelt history to negotiate some money off. It's now 16 years old, has done 90k on what we presume to be the original belt, and as it's a workhorse of little sentimental or economic value if it lets go it let's go and he'll get another one.

Having said all that, if I were to buy a low mileage minter to see me out then I'd get the belts changed for peace of mind.

You pays your money (or not) and you takes your choice.

[Avulon]

Originally Posted by SD1too

No, I'm changing them according to MG Rover's mileage recommendation.

Ah, ok I think I see. You are changing the belt(s?) based solely on the mileage recommendation, not on the condition of the belt(s).

[Arctic]

Hi Avulon.
Simon said.
Remember that this belt has lasted over three times as long (3 x 6 years) as some people insist it will last. It has covered 90,608 miles which is why I am changing it.

Stated in the first post, of this thread, therefore he is changing them on mileage basis rather than the time scale.

[SD1too]

Originally Posted by gazcon

... I don't recall ever seeing a V6 that was killed by the belts / pulleys letting go .... it seems undeniable that these belts last considerably longer in real world use than the ... 6 years stated.

Hallelujah!

I bought a V6 estate ... it had no cambelt history ... It's now 16 years old, has done 90k on what we presume to be the original belt ...

Thanks for this evidence Gary. With the addition of the Gaydon V6 that’s three cars which have exceeded the six years and survived unscathed. There are other purchases like Gary’s which we hear about on the forum. But we don’t hear of any which have suffered the fate repeatedly claimed in this thread.

Originally Posted by Avulon

Ah, ok I think I see. You are changing the belt(s?) based solely on the mileage recommendation, not on the condition of the belt(s).

I’m not sure of the point you are trying to make here Mr. Avulon. Are you suggesting that I (and others) should periodically expose the belts to assess their condition? If so, when would you do that? Also, are you aware of how much dismantling is required to achieve this?

Alternatively are you suggesting that since my belts have been proven to be in perfectly good condition after nineteen years that I should leave them in place?

As Steve (Arctic) has kindly pointed out, I hoped that I had made my position clear. Timing belts wear when they are doing mechanical work, that is when the engine is running. Therefore I accept MG Rover’s guidance that 90,000 miles is their expected life. I also accept that it would be an unacceptable risk to exceed this mileage without periodically checking their condition. Unfortunately that is impractical and so it makes sense to renew them anyway, at 90,000 miles or thereabouts.

Since belts which are not doing mechanical work cannot wear, and since they are manufactured from extremely tough and resilient materials which are resistant to most contaminants (see the Gates document posted by MarinaBrian), it makes no engineering sense to replace something which shows no sign of deterioration simply on an arbitrary time basis.

I hope that the above helps but please do come back to me if you need further clarification.

Simon

[neilll]

Simon,
Please get on with the job of changing your belts instead of trying to convince everyone how great you are because yours has lasted 19 years (or what ever it was)! You have shown everyone that yours do indeed need changing as the "ribs" are showing through. I agree with you that 6 years is not really a good marker for changing them, but you really need to know the history of how the car has been used to evaluate when to change them!
My last purchase came with no history of belts and I took the decision to have them changed by a respected trader on the forum who on inspection said they looked fine and dont really need changing (car on 120,000). My decision was change them anyway! At least I can drive around knowing the belts wont let go, something else might though!!

Neil

p.s.
If you spent your time changing your worn belts instead of pontificating on your thread , you could be driving round now not worrying will they wont they!!

[SD1too]

Originally Posted by neilll

... yours do indeed need changing as the "ribs" are showing through.

This is a new and interesting claim which many seem to enjoy quoting. Yes, my belt has a pattern of shading on it corresponding to the teeth but what is it and what is its significance? If you look at the Gates document which MarinaBrian provided there is a section on troubleshooting. There you will find a small photograph of a belt which has this same shading. Note that Gates does not refer to it at all. The picture is there to illustrate shredding of the edges of the belt, which I do not have. Wouldn't you think that if the shading was a recognised symptom of impending failure that Gates would be shouting about it from the rooftops?

But they aren't.

Thanks for raising this important point Neil.

Simon

[mbonwick]

Originally Posted by SD1too

they are manufactured from extremely tough and resilient materials which are resistant to most contaminants (see the Gates document posted by MarinaBrian), it makes no engineering sense to replace something which shows no sign of deterioration simply on an arbitrary time basis.

How about the degradation you can't see? Only way to prevent against that is on a statistical basis, which is where "arbitrary" time/mile intervals come from....

[SD1too]

Originally Posted by mbonwick

How about the degradation you can't see?

I’m not sure that I understand your point Michael. If you can’t see degradation how do you know it exists?

Only way to prevent against that is on a statistical basis, which is where "arbitrary" time/mile intervals come from....

What statistics and how do you think that they are compiled? There simply aren’t enough broken KV6 cambelts to provide a representative sample. The conclusion would be that the failure has been caused by an external influence (which I think is highly likely if under 90,000 miles).

No, the “arbitrary” time interval is exactly that. It was calculated by dividing the expected service mileage (easy to test) by an annual mileage which was determined to be commercially competitive. It has nothing to do with statistics.

Simon