General Cambelt wear factors

[d_onions]

Hi,
As my car is due it's cambelt replacement (81.5k miles), I was just wondering what is the most significant issue with wear? By this, I mean my car has done the majority of it's miles on the motorway, therefore the total number of hours the engine has been running would probably be comparable to a much lower 'average driving conditions' car. Also, with higher miles on a relatively new car, the age at which the cambelt is replaced would be lower than average. I appreciate that at motorway speeds the rpm would be consistantly higher than, say, town driving, but probably with less strain on the engine revving up/down. Would it be more fair to say that the time a cambelt would need replacing should be based on the number of hours the engine has run, or age of the cambelt, as opposed to the number of miles the car has covered?
Ta
Dave

[zollaf]

you also have to look at the number of times the car has been started/stopped, as this puts a great deal of stress on a cambelt, as the stiction of the cams has to be overcome, and the pump on an old fashioned tdi.

[james_tiger_woo]

Different conditions and other factors might need to be considered I suppose - speed of the engine, air temperature, humidity, etc.

Engine speeds on the motorway could still be lower than town driving as you might stick the car in 6th and 2000rpm and tootle along, whereas in town you might have to do 3000rpm just to keep flowing.

I suspect that 80k is a guide as much as anything - If it went at 40k and 2 years you might have a case against VW for parts that are not fit for purpose, at 60k and 5 years, you probably wouldn't.

[gamichea]

Your service book might say 80k/6 years as does mine (reg.May 06) but VW changed the TDI interval to 60k/4 years soon after.

In any case there are no ifs and buts about change intervals around type of use, driving style, etc. If yours failed tomorrow it would be your responsibilty alone I'd guess.

[MyMidLifeCrisis]

Whilst 80k must include a substantial margin of error, it's a brave man who gambles the cost of a cambelt service against that of a replacement engine. At least if a cambelt let's go before the recommended milage you have the moral high ground in any claim.

I've just had mine replaced at 70k, mainly because I'm a coward!

[Col]

I've changed and had changed loads of belts in the past on my various cars and in my experience the belts have always been fine and probably good for many 1,000's more miles.

Time and time again though, tensioners, aux rollers and water pumps have been on their last legs.

Ironically then, I'd suggest the belt would be fine, it is a perepheral component that is most likely to cause the belt to fail.

And never ever skimp or try to extend the interval, if anything reduce it.

[taylora]

I've had problems trying to find out what mileage the cambelt is supposed to be changed.

Our 2.0TDi has 78k miles on it so I thought best call around and get some prices for the change. First dealer said 80k miles and £360, second dealer 60k miles and £460, third was 95k miles and £540, fourth dealer said he needed the engine number to check.

Called VW, they confirmed 95k miles or 4 years based on my VIN number. Somewhat concerning some ******** are happy to take my money to change the belt far earlier than required by VW.

[maisbitt]

It's all risk vs effect. The risk of a parachute not opening on a parachute jump is small, but if it happens, you're dead.

Same with the Cambelt, Something that VW are confident will last 60K/80k or whatever for the terms of their guarantees (vs the risk of paying out under warranty) will probably last half as long again. But can you risk neglecting that part for a few extra thousand miles, when the consequence of failure is an engine rebuild and a few bent valves at the very least?

[d_onions]

Just a quick question then... Why the massive difference in mileage? Have the 2.0tdi 140 components changed so much that there is a 35000 mile difference depending on your VIN? Just for info I managed to get VW to pricematch mine at £301 including the water pump...

[Stuart W]

you also have to look at the number of times the car has been started/stopped, as this puts a great deal of stress on a cambelt, as the stiction of the cams has to be overcome, and the pump on an old fashioned tdi.

I'm not so sure if starting/stopping should be that much of an issue for the average driver. I'm about to get mine done at 80,000, and since the car is a taxi it's stopped and started hundreds of times a week, thus I wouldn't be surprised if it's been started/stopped 50,000 times, which is quite a lot compared to the average driver.

(It's not that I do hundreds of jobs a week - often it has to be started several times between jobs to move up the taxi rank).

I always assume that changing gear puts a good bit of stress on it, presumably depending on how gentle you are with the clutch - let it out quick and it must result in a good pull on the belt. I would assume that constant cruising on A-roads and motorways is pretty stressless.

[Stuart W]

Hope I'm not tempting fate with that, by the way :D

But my old Mondeo had a similar start/stop life and never a problem with the timing belt - I had it done at around 70,000, 150,000 and dumped the car at 233,000, so my average was nearer 80,000.

Starter motor never gave problems either - although this was a well known early Mondeo fault - and I must have stopped/started the car 100,000 times.

The clutch and gearbox were also untouched, and I quite possible changed gear around a quarter of a million times.

[mhurer]

On my old Passat (B5) when VW changed the cambelt replacement interval to 40k/4 years, they decided to contribute 25% to the cost without me even asking. If they are again changing the interval for the B6 from what is documented in the service book then I would have thought the same rule applies - something worth arguing for anyway, as I can't imagine they would be forthcoming.

[Dozz]

I pick up my 2005 B6 140 PDi tomorrow from the main ********. Part of the deal when I brought it was the cambelt was due. This was not down to the mileage but down to age. Mine is meant to be changed at 80k miles or 4 years. It's been changed at 34k and 3.5 years. I've repaired cars which have done there cambelt. I had Pug 405 mi16 given to me because of the belt going. All 16 valves were bent. So I always do them early now. A snapped belt on a VW diesel is going to cost a fortune. A friend had his snap on his Lupo SDi. The head was scrap. All the cam caps broke and the cam just thrashed around in the head. Was utter carnage.