KV6 Belt Change

[SD1too]

Originally Posted by Dorset Bob

The time limit is in place to capture the low mileage engines, which are often operated in more arduous conditions.

I accept your point Bob but there is actually a separate schedule for this. It covers engine oil & all filters, brakes, suspension and steering and ancilliary drive belts but not the timing belts. How strange eh?

This is, more often than not, frequent cold starts and operating in stop/ start situations. This obviously places more wear and tear on the components (including the belts) compared to a vehicle that, for example, spends most of the time on a motorway.

I agree, but if the additional wear and tear were believed to cause failure before 90,000 "normal" miles, then I'd expect the cambelt to be included in the "Arduous driving conditions, additional requirements" section of the service sheet.

I think that it is best that people are not encouraged to play Russian Roulette with their engines.

Two points on that Bob: it's only Russian Roulette if you believe in the six year period and the only thing that I'm encouraging is thought and analysis of the evidence available. Each reader is entitled to do what they wish with their engine.

Originally Posted by Bolin

Simon, how do you know that the Gaydon has not had its belts changed?

I don't Colin. If it has (and I very much doubt it) then I won't be able to quote that car as an example any more. However, there is club members' evidence too, and those cars have been subjected to normal, or perhaps abnormal, wear and tear as Bob mentioned.

Simon

[Dorset Bob]

In the recent past, I have spoken to the curator at Gaydon and the first Rover 75 car is still on the original belts. This is due to the unusual scenario of it being predominately a display car, being unregistered and not used on the road.

I feel that it is a red herring to use this as an example, as I can’t think of any other car that is like this one.
Perhaps this one currently for sale would be a better example.


http://www.the75andztclub.co.uk/foru...light=motorway

[Stag>75]

Only as FYI: I changed the original belts on my 2001 R75 last year with it having done 75,000KM's. The previous one owner was elderly and the car clearly had an easy life. The belts were perfect, no cracks or any sign of deterioration. I could not tell any difference in length between the original and the new ones. I do think the idler and tensioner pulleys may have been a bit noisy, but then again I believe one of the new ones made a bit of a metallic scraping noise for a few minutes when I started it up ....

But my Power Steering pump has a whirr, I can only put that down to the strut top bearings being almost seized when I bought it. Seems to be one issue not driven by mileage.

[murphyv310]

Hi.
When I was in my last job one of our customers was Gates in Dumfries. I managed to chat to one of the boffins one day and he came up with some interesting points.
A great many belts are generic, often they are the same belts used in many different applications, not just as timing or cam belts but transmission drive belts for road sweepers, conveyor systems and all sorts.
He made the point to me that on other uses the belt is "inspection" only on an annual service and the belt can actually last 20 or more years with no visible wear, in other cases they can fail in 5 years.
The reason the car manufacturer specifies a time as well as mileage is the different operating conditions in a car.
The loading on a timing belt is constantly changing, pulses from the cams, changes in engine speed alters the loading but more importantly thermal changes and that happens on low mileage engines too.
As my man in gates said to me, a toothed belt that is the same type as in an engine that's used on a conveyor system will last for years but may just break in an engine due to ageing, I personally would rather stick with the recommendations, its not a conveyor we are driving!

[SD1too]

Originally Posted by Dorset Bob

In the recent past, I have spoken to the curator at Gaydon and the first Rover 75 car is still on the original belts.

Thanks Bob for clearing up that point.

I feel that it is a red herring to use this as an example ...

I can understand this, since your reasoning for replacement on a time basis includes possible increased stress due to the number of engine stops and starts. But for those who advocate replacement after 6 years per se, surely the Gaydon car is the perfect example. It may not include arduous driving conditions but it certainly addresses the time factor alone.

Simon

[murphyv310]

One thing to consider is this. How many engines have you stripped that have been stationary for weeks or months? Well if you have you will see the belt has taken on a "set" where it was stopped at. This happens even over night. This is actually lightly stressing the belt, once running the stress changes again. Surely a belt stopped is still under stress and likely to develop minute cracks around pulleys, the set they develop would in my opinion be the worry on low mileage cars

[Phil-T4]

Personally i've not seen a "worn" belt as such but the idler pulleys are a different matter, the plastic wheel broken, cracked and the centre bearings breaking up.

Its the same scenario as engine oil, change it every 15000 miles or yearly, so if you only did 1K per year would you only change it after 15 years ignoring the recommended time interval? No i dont think so!

[mh007]

I would agree that the only 'broken' or visually 'worn' belts I have come across on the KV6 have been the result of one of the three pulleys (tensioner/idler/water pump) either broken up or worn due to bearing issues (or both if the bearing has seized !)

I also agree that because these belts are under a constant tension & this must take its toll even you can't actually see it.

In my opinion, it's a no brainer..............if you care about the car & its engine, why wouldn't you change the belts etc on or even a little before the recommended interval ?!!

[topman]

I think you can in some ways ignore the time limits in the right circumstances but you have to be sensible. In years to come would a barn find 30 years old with 30,000 miles be left till it hits 90,000 miles? I don't think you would.

[Richcl]

I'd have to change my belts when due as the stress of driving and thinking it could go anytime would be to much!

My old Cortina broke it's cam belt a few times, used to go when pulling away from standstill. Not the best thing to happen at traffic lights when sat in a queue of traffic!