Cam belt - a vehicle's Achilles heel?

[Jo May]

Took our camper in today for a cam belt. It's 5 years old and the van has done 'only' 16,000 miles.
It'll cost £600 - 700.
What a horrible, poxy, inadequate, weak link this thing is in a complex vehicle, one that, touch wood has run fine to date.
Of course, £600 would be 'cheap' if it did happen to snap. But it's scant consolation for a piece of kit that is basically not up to the job. I know they have chains now - are these changed periodically?
But whatever, the majority are rubber and integral to the just about every vehicle. You'd think that by now they'd have come up with a better system than something that needs to be changed after so little mileage?

I ponder this conundrum, and resultant hit to the wallet, on my 3-mile walk home having dropped the van off. It's a walk I normally thoroughly enjoy along the canal towpath. But my mood is rather dark, summed up when my tracky bottoms are muddied by two passing dogs that jump up - 'he's only playing', said one owner, 'sorry, he's just learning,' said the other. Learning?!
To put the tin lid on it, as it were, I got soiled by a passing duck as it crapped on my anorak!

Ruddy cam belts.

 

[ivorantony]

If you think that’s bad, feel sorry for the poor buggers that have belts running in oil,
Transit owners are looking at a bill of £1400 or a completely destroyed engine,
They don’t call the eco boost engine ecoboom for nothing

 

[Googlebot]

Cam belts are quieter, more economical and easier to change. Chains also stretch and can rattle, they are usually much harder to get at as well.

Wet belts, now that’s another story.

I hate dogs jumping up as well.

Cheer up, nights will be getting shorter soon.

 

[meanders]

Belts are also a lot lighter and quieter. Not saying that overrides the disadvantages.

 

[headlight]

I had the auxiliary belt fail on my works van, Transit Connect, last Wednesday.
Garage just rang me £2,000 to sort it out.
New alternator, power steering pump, water pump and injection pump needed plus obviously a new auxiliary belt.
Didn't make a noise when it failed at 50mph and I stopped as soon as a warning came up on the dash.
All from a snapped rubber auxiliary belt.

^{_{Subscribers  do not see these advertisements}}

 

[Jonno1103]

If you think that’s bad, feel sorry for the poor buggers that have belts running in oil,
Transit owners are looking at a bill of £1400 or a completely destroyed engine,
They don’t call the eco boost engine ecoboom for nothing

Oh here we go, the usual copy & paste wet belt story telling. Less than 5% of Transit & Transit Cutom sales since 2016 have suffered. It's roughly 14000 vans out of over 350,000 sold. Yes, the engine is so bad VAG are using it from 2025.

Depends who you buy the moho from with the Fiats, many of the dealers who only sell used change the belt prior to sale if they're over or nearing the 5 years.

 

[Neilh]

Cam belts are quieter, more economical and easier to change. Chains also stretch and can rattle, they are usually much harder to get at as well.

Wet belts, now that’s another story.

I hate dogs jumping up as well.

Cheer up, nights will be getting shorter soon.

Chains don’t stretch, the pins could possibly wear.
Wet belts, why would you.

 

[Barchetta47]

The flip side is our ancillary belt snapped, took the cambelt with it whilst in Spain. Engine out etc €5500 which included a new clutch. £700 I’d snap your hand off. Sit down have a cuppa, all is well!!

 

[Googlebot]

Chains don’t stretch, the pins could possibly wear.

So what happens when the pins wear?

 

[ivorantony]

Oh here we go, the usual copy & paste wet belt story telling. Less than 5% of Transit & Transit Cutom sales since 2016 have suffered. It's roughly 14000 vans out of over 350,000 sold. Yes, the engine is so bad VAG are using it from 2025.

Depends who you buy the moho from with the Fiats, many of the dealers who only sell used change the belt prior to sale if they're over or nearing the 5 years.

This is copy and paste,
The Ford Transit EcoBlue engines incorporate the wet timing belt system to enhance engine performance. This design choice was first introduced with the 1.0-litre EcoBoost engine in 2012 and has since been adopted in various Ford models

I’m retired from the motor trade now but cannot count how many eco boost engines have let go with mileage well below 80,000 miles when Ford said they would last at least 150,000 miles,
So I’m talking real world, not bar room gossip.
Because other manufacturers adopt it doesn’t make it fit for purpose,

^{_{Subscribers  do not see these advertisements}}

 

[Jev88]

Chains - 100 to 200,000 miles lifetime.
Belts - 40 to 60,000 depending on manufacturer.

Or so I was advised.

 

[Just smiffy]

In the “good old days” when I always bought older cars as I couldn’t afford anything else, cars with tens of hundreds of miles on the clock and probably never had a belt change and I certainly didn’t renew one in the 30-50k in the mileage I’d put on and fortunately never had one go… so are we being scared into renewing the belts on vehicles..? One particular petrol car I had I put over 50k on it and never changed the belt, were they supposed to be done every 5k on cars too

On my 3ltr ducato it’s a chain and now on 134k I don’t think it’s ever been done but drives like new….

 

[Guigsy]

Chains - 100 to 200,000 miles lifetime.
Belts - 40 to 60,000 depending on manufacturer.

Or so I was advised.

Tell that to BMW and Mini owners.

 

[Jev88]

Tell that to BMW and Mini owners.

BMW - only ever had a 3 series 320d and did 90000 miles and no advisory from main dealer to change belt/chain.....

Mini - I know there is quite an expensive Cambelt service at 100,000 miles which is why many are sold around that mileage.

 

[Guigsy]

BMW - only ever had a 3 series 320d and did 90000 miles and no advisory from main dealer to change belt/chain.....

Mini - I know there is quite an expensive Cambelt service at 100,000 miles which is why many are sold around that mileage.

The N20 engine has issues with it's chain guides and it lunches the engine. Sometimes within 20k miles and 2 years.

^{_{Subscribers  do not see these advertisements}}

 

[dunnah01]

Chains don’t stretch, the pins could possibly wear.
Wet belts, why would you.

Normally the nylon sliders wear until the hydraulic adjusters run out of throw and then the chain starts to slacken and rattle

 

[jockaneezer]

An extract from the 1904 Carriers, Shifters and Furteler's Almanac;

Fowler cheaped out and fitted a wooden handle to the coal shovel on my steam roller and it's just snapped on me, why, oh why couldn't they have just used a wrought iron handle !!!

My son briefly had a Skoda Yeti, the oil pump is driven by a short rubber timing belt that runs in the oil filled sump, which ensures, as it starts to break up and degrade, the rubber fragments don't have too far to go to block up the gauze filter on the oil pick up tube, but time wise, it generally makes it through the warranty period !

Going by Ford's figures, that's a 4% failure rate, seems a bit high for such an important component ?

 

[Guigsy]

Chains do get longer when they wear. Although they don't physically stretch, the pins and plate holes get worn and the very slight increase in play adds up over the length.

 

[IRHP]

Had a vauxhall cavalier 1.8 Sri. Cambelt went at 70,000 miles. Quite a bit of damage but labour was cheap then. I think it was about 30 something years ago. Long before the Internet. I'd never heard of changing a cambelt until mine broke.

 

[Guigsy]

An extract from the 1904 Carriers, Shifters and Furteler's Almanac;

Fowler cheaped out and fitted a wooden handle to the coal shovel on my steam roller and it's just snapped on me, why, oh why couldn't they have just used a wrought iron handle !!!

My son briefly had a Skoda Yeti, the oil pump is driven by a short rubber timing belt that runs in the oil filled sump, which ensures, as it starts to break up and degrade, the rubber fragments don't have too far to go to block up the gauze filter on the oil pick up tube, but time wise, it generally makes it through the warranty period !

Going by Ford's figures, that's a 4% failure rate, seems a bit high for such an important component ?

Ford, VW group, PSA group... Lots of manufacturers tried wet belts. Quieter, smoother and more efficient...

Fords have a particularly high failure rate. But a lot of it is a snapped idler bracket that causes the belt to get chewed. Which I think has now been redesigned? Ford are still maintaining that if you change the oil with the correct type at the required intervals, longevity is fine. It's twice as expensive to service as an external belt, but apparently it needs to be done half as often.

^{_{Subscribers  do not see these advertisements}}

 

[gus-lopez]

New alternator, power steering pump, water pump and injection pump needed plus obviously a new auxiliary belt.

Why does it need all that for the auxiliary belt snapping?

 

[PaulW2]

Much prefer chains. The argument that they are noisier seems odd to me. I have a 330 BMW and it sounds perfectly ... normal. Ditto other cars I had with cam chains. And I do resent the "5 years or 60 k miles" replacement cycle of the belts.

 

[headlight]

Why does it need all that for the auxiliary belt snapping?

Because the belt wrapped around various parts and destroyed them.
The power steering pump dumped it's fluid into the alternator when the belt damaged it which is why they've said it needs a new alternator as well.
When I pulled over there was coolant and fluid everywhere.
I am more than a little surprised at the amount of damage caused but the garage is my local trusted one and I went to school with owner so i have no reason to doubt what he said.

 

[Neilh]

So what happens when the pins wear?

It gets bigger

 

[Kannon Fodda]

Having seen the results of a timing belt failing on one of the first 1980s Escorts fitted with one, I'd rather not take the risk, and just accept changing periodically is part of vehicle maintenance. Even the chain types will eventually wear, but belts are probably much more vulnerable especially for engines that don't run for some time so the belt is stuck in one position. We do of course have the improved efficiency of engines with belts, compared to the pre cambelt systems of the 1950s.

But the wet belt system of the Ford does appear to be a real issue. Cost of replacement is much higher due to the special tooling needed, so many garages simply cannot do it and those that do have to charge accordingly.

^{_{Subscribers  do not see these advertisements}}

 

[headlight]

Ford used to do an engine with neither a cam belt or chain, I think it was the Essex V6 iirc.
The cams were driven by a gear cog.

 

[meanders]

Chains don’t stretch, the pins could possibly wear.

Many, many years ago I was involved as a student with rebuilding the engine in an XK120. That included replacing the crankshaft to sprocket timing chain. The old one was visibly physically longer than the new, I am guessing an inch or more from memory. Now you can call that what you like but the chain had obviously stretched.

 

[Neilh]

I've had several Audi V6 Tdi one of which did 180,000 miles and the engine still sounds smooth, no chain rattle, it was serviced regularly at 10k and was the most reliable car I've owned, pre DPF and addblue.

 

[Neilh]

Many, many years ago I was involved as a student with rebuilding the engine in an XK120. That included replacing the crankshaft to sprocket timing chain. The old one was visibly physically longer than the new, I am guessing an inch or more from memory. Now you can call that what you like but the chain had obviously stretched.

The chain had worn, technically not stretched.

 

[meanders]

I understand totally the engineering behind your statement, that the links don't stretch, (although that itself is debatable), but we are talking about the "chain", not it's component parts. If the component parts had worn, but the "chain" is longer than it was when new, then factually the 'chain' has stretched. It hasn't worn longer. That would be an engineering impossibility.

Even so, if you put anything under constant tension it will stretch. You might struggle to measure it, but it's a well known fact of metallurgy, physics and chemistry... Or at least was when I studied.