Start/Stop Linked to Timing Chain?

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My guess is its the sheer number of starts compared to the typical 1-5 starts a day and the initial inertia of the engine cranking has the effect of chain wear. As mentioned we will never know for sure without a complete failure mode analysis. But it is a theory.
Certainly my local indy complains about the system and points some blame to it along with the stop start wearing out engine mounts prematurely. Most people turn it off and find it irritating. I do.. LOL
 
Engine mounts , tensioner , chain , battery , alternator , starter motor , ring gear , engine bearings , it's a no brainer .
 
The stop start feature could possibly impact the timing chain , and potentially other bits and bob's in the engine due to the inertia on start up, hot or cold. An engine with a finite life might be designed for one million engine starts (for example) all of a sudden has to deal with ten million start cycles in it's lifetime. I have not heard of the timing chain noise being linked to the stop/start function before, but it can't be discounted . My personal view is that stop/start is flawed, most engineers will say that once you get something running (overcome inertia using much energy) keep it running for as long as you possible can bringing it to a halt only if you really have to.
 
My guess is its the sheer number of starts compared to the typical 1-5 starts a day and the initial inertia of the engine cranking has the effect of chain wear. As mentioned we will never know for sure without a complete failure mode analysis. But it is a theory.
Certainly my local indy complains about the system and points some blame to it along with the stop start wearing out engine mounts prematurely. Most people turn it off and find it irritating. I do.. LOL
I confess that I have no issues with start/stop. On my car it operates imperceptibly so I doubt it's putting too much extra strain on anywhere.
 
Knight, you might doubt that it is putting 'extra' strain anywhere. I can tell you it is , on everything from the battery(ies) to the starter motor, plus the extra pump that had to be fitted to keep gearbox oil pressure up (on some vehicles) . None of this is a problem if the design is right. But stop/start is adding 'extra strain' somewhere.
 
Knight, you might doubt that it is putting 'extra' strain anywhere. I can tell you it is , on everything from the battery(ies) to the starter motor, plus the extra pump that had to be fitted to keep gearbox oil pressure up (on some vehicles) . None of this is a problem if the design is right. But stop/start is adding 'extra strain' somewhere.
But how much extra strain? And how does that compare to the strain when the engine is idling? An ICE is not running with constant forces: the various parts are constantly accelerating and decelerating during the combustion cycle. This means that the camshafts are trying to speed up and slow down as valves open and close, the crankshaft is flexing with each power stroke... and the timing chain is in between all of that.

I don't know the answer: manufacturers' behaviour in the past decade regarding emissions means that we can't trust that their choices are the best compromise, and different driving environments will give different results anyway. But there will definitely be less strain on the engine parts when it is stopped compared to when it is idling.
 
My starting routine is - start engine, wait a few seconds in case of any unknown noises, turn Off ECO stop/start, turn on Comand.
 
As mentioned we will never know for sure without a complete failure mode analysis. But it is a theory.
More a hypothesis than a theory? A theory is a principle set to explain a phenomenon already supported by data.
 
No problem.

I take it your car is a manual gearbox then not auto?

Fly wheels (dual mass fly wheels) make a loud rattle/knocking sound if they fail. You would certainly here it but only when driving not when idling in neutral.

Its possible given the mileage. Which garage did you use out of interest? Do you trust them?
Wait a min!!!
I just realised that autos don't have flywheels, and I have an auto, so what do they mean the flywheel is on its way out?
Guess they are not to be trusted then :mad:
 
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I don't understand how the stop/start can increase timing chain wear. The main cause for wear is when starting the engine from cold when there is less lubrication on the chain and sprockets. Start/stop only functions when the engine has warmed up and the oil is flowing well.
I think it has to do with there is less oil distributed due to sitting for a few seconds when Start/Stop has kicked in and this slight reduction in oil can cause the increased wear maybe?
 
Why don't you get the timing checked. Saves any guesswork then. If its out then it needs doing.

I think the thoughts about the stop/start causing more chain wear argument is false.
Reading all the posts does make it seem like the Start/Stop function doesn't cause more wear if you take into consideration all the parts not moving when stopped.

I would like to get it checked but I don't really have the time especially if I'm not hearing anything at the moment.
 
But how much extra strain? And how does that compare to the strain when the engine is idling? An ICE is not running with constant forces: the various parts are constantly accelerating and decelerating during the combustion cycle. This means that the camshafts are trying to speed up and slow down as valves open and close, the crankshaft is flexing with each power stroke... and the timing chain is in between all of that.

I don't know the answer: manufacturers' behaviour in the past decade regarding emissions means that we can't trust that their choices are the best compromise, and different driving environments will give different results anyway. But there will definitely be less strain on the engine parts when it is stopped compared to when it is idling.
Very little extra strain is the answer, but starting anything from a standstill to (lets say) 900 RMP in one second will cause more strain than moving that thing from 900 RMP to 2500 RPM in the same time frame as an example. I don't know the exact answer either , but I do know that once you get over the initial inertia of pushing a broken down car , keeping it moving is a bit easier.
 
Very little extra strain is the answer, but starting anything from a standstill to (lets say) 900 RMP in one second will cause more strain than moving that thing from 900 RMP to 2500 RPM in the same time frame as an example. I don't know the exact answer either , but I do know that once you get over the initial inertia of pushing a broken down car , keeping it moving is a bit easier.
Whilst parts of the engine rotate, some of the important bits reciprocate. Those parts having momentum is a bad thing, as that momentum has to be lost every time they change direction. Kinetic energy (momentum) is proportional to the square of the velocity, so I expect that the forces on the reciprocating parts between 900 and 2500 rpm will be far, far higher than those between 0 and 900 rpm.

This thread is - and I fully include myself in this - no better than a bunch of blokes down the pub, full of conjecture and preconceptions. Unless someone chips in with real evidence we may as well all stick to our personal expectations and carry on as before.
 
The best information period is from mechanics / independents .

I think it's more chain tensioners that get prematurely worn out .
 
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Whilst parts of the engine rotate, some of the important bits reciprocate. Those parts having momentum is a bad thing, as that momentum has to be lost every time they change direction. Kinetic energy (momentum) is proportional to the square of the velocity, so I expect that the forces on the reciprocating parts between 900 and 2500 rpm will be far, far higher than those between 0 and 900 rpm.

This thread is - and I fully include myself in this - no better than a bunch of blokes down the pub, full of conjecture and preconceptions. Unless someone chips in with real evidence we may as well all stick to our personal expectations and carry on as before.
I mean you have point, I feel it just comes down to driver anticipation when driving, Like if you come up to a junction and stop for half a second and the engine cuts out for that amount of time then it's obviously pointless but sitting at the lights for a min then I feel like its worth it.
At least that's what I think and I'll try to make it an active prosses to just switch it off and on when necessary.

Thank you, everyone, for the help, please post if anyone has any more information 👍
 
Anyone chance someone can post a picture of the location of this 7.5a fuse in the w204 please?
 
F
Whilst parts of the engine rotate, some of the important bits reciprocate. Those parts having momentum is a bad thing, as that momentum has to be lost every time they change direction. Kinetic energy (momentum) is proportional to the square of the velocity, so I expect that the forces on the reciprocating parts between 900 and 2500 rpm will be far, far higher than those between 0 and 900 rpm.

This thread is - and I fully include myself in this - no better than a bunch of blokes down the pub, full of conjecture and preconceptions. Unless someone chips in with real evidence we may as well all stick to our personal expectations and carry on as before.
Five Alive , I see you only joined this Forum recently (welcome) You will have spotted that nearly ALL of the threads on here end up like a bunch of blokes talking in a pub , That's what keeps it entertaining . :p :thumb:
 

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