Stop Start kills cam chains

Botus

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I've not read anyone indicate this is a driver of cam chain failure but it clearly will be a significant issue.

A taxi will do mega miles without issue as it is often running at a sensible operating temperature, but another factor will be that fact the engine is often running continuously so the wear and tear on a cam belt or chain is tiny.

Its not just start up that's bad for engines, actually getting a cam ot move is hard work. If you have ever tried to spin a cam (when bolted in place) the shear force required to get it to turn is extreme, once you have it spinning its actually nothing to maintain it.

So any stupid stop start system is putting exceptional demand on the cam drive, hence so many failures.

What made me think of it, was telling a bloke when we were in stop start traffic he's ruining his engine by using it. He was being smug because "it saves him money" I replied it doesn't. A new cam chain, battery, starter motor, exhaust system and engine, is quite pricey vs 3 gallons of petrol over the same period !!!

And the environmental damage producing those parts is also far higher.... each time the thing cuts out ion traffic think 1k miles off the engine's life vs a Taxi driver's expectations !!!
 
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Craiglxviii

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Yup. I purposely turn the idle stop/start off every time I start the car.
 

malcolm210

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Couldn’t agree more, stop/start may have a place in the centre of a congested city like London to reduce pollution but there is little point in it elsewhere, for anyone keeping a car beyond three years old it doesn’t make sense because of excessive wear on the engine, as soon as the car tells me it’s active I turn it off, good battery indicator though
 

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I've not read anyone indicate this is a driver of cam chain failure but it clearly will be a significant issue.

A taxi will do mega miles without issue as it is often running at a sensible operating temperature, but another factor will be that fact the engine is often running continuously so the wear and tear on a cam belt or chain is tiny.

Its not just start up that's bad for engines, actually getting a cam ot move is hard work. If you have ever tried to spin a cam (when bolted in place) the shear force required to get it to turn is extreme, once you have it spinning its actually nothing to maintain it.

So any stupid stop start system is putting exceptional demand on the cam drive, hence so many failures.

What made me think of it, was telling a bloke when we were in stop start traffic he's ruining his engine by using it. He was being smug because "it saves him money" I replied it doesn't. A new cam chain, battery, starter motor, exhaust system and engine, is quite pricey vs 3 gallons of petrol over the same period !!!

And the environmental damage producing those parts is also far higher.... each time the thing cuts out ion traffic think 1k miles off the engine's life vs a Taxi driver's expectations !!!

I’ve been saying this for ages, the snatching of the chain on start/stop must wear the chain more. We see more cars with noisey chains at lower mileage’s that use the stop start system.
 

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I rarely use stop start just the odd occasion to check it’s all ok.

Mind you I very rarely use my car in an urban environment.

Robin


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00slk

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Both my 47year old cars have stop/start, real pain in the butt till there up to running temp :rolleyes:
 

Yugguy

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Ss is a gimmick to fudge official mpg figures.
 

ajlsl600

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gimmick exactly !!!! ,a cheap addition for car makers that looks like an effort to keep the ,,greens,, happy ,but will have the later owners spending loads on the related items as stated above , any motor i get will have that dissabled the same day . great for dealers and in my view just anoter way that maker know someone WILL be sitting at the parts counter.......
 

brandwooddixon

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I'd agree with this.

Having a gear, chain, tensioner and guide all changed on one bank of my low mileage (40k) CL500. Just waiting for the components to arrive from Germany as none in the UK dealer network.

Even though the car had a full MB dealer history, it obviously spent most of its time in urban driving prior to my purchase. I tend to do a lot of motorway driving, which is just what the doctor ordered for this engine.
 

umblecumbuz

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Obviously a hidden hot topic.

Completely agree with Botus. On Fiats, this is showing up as a major issue, and a killer of expensive stop/start batteries. Steering problems also arise on the smaller Fiats especially, as they are fully electric, very power-hungry, and sensitive to battery drain.
 

LostKiwi

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You can also add bearing and crank wear. Everytime the engine stops it loses lubrication and we all know the greatest amount of damage to an engine occurs in the first ten seconds after it starts.

Interestingly with direct injection petrol engines they don't need to use the starter to restart the engine (not the case with diesels). With a petrol engine when it stops if the fuel isn't injected and the engine stopped just after TDC then a restart can take place by injecting fuel and providing a spark.
 
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daibevan

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I have always felt this was the case, it's nice to see I wasn't just being paranoid. I'd only ever use it if stuck in a long motorway tailback. (Not that I have it at the moment). It's just another feeble nod to being green that in reality makes things worse.
 

alexanderfoti

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I think its a combination of both introduction of single row timing chains, and stop start systems at the same time.

I would bet money that double row chains with stop start systems have fewer issues.
 

umblecumbuz

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I think its a combination of both introduction of single row timing chains, and stop start systems at the same time.

I would bet money that double row chains with stop start systems have fewer issues.

They do anyway, regardless of stop/start 'technology'.
 

alexanderfoti

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They do anyway, regardless of stop/start 'technology'.
True, rubbish idea. Save 1% fuel by removing the additional timing chain row.

The manufacturers don't care about long term longevity. IF they last 100k/3 years then that satisfies their warranty requirements.
 

ajlsl600

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dead easy ,just dissable. wish i had a dissable buton for abc as well ,then at least if it sxxs itself halfway thru italy i can still drive home !!!
 

flowrider

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I had start/stop on my ML350 but every time i got in the car i turned it off. On my Audi i have coded the start/stop button to remember its last position so no more having to manually turn it off. My SL is too old for start/stop.
 

brandwooddixon

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I'm not a great fan of stop/start, even though my car has it as standard.
As well as cam chains I suspect that there will be a spate of turbo failures on these cars.
Typical drive for me involves a long stint on the motorway, then three sets of lights 100 yards apart from the motorway exit slip road as I go home. I'm always mindful of that hot turbo having all of its cooling oil stopped as I get caught at all of those lights.
 

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