car not starting sound
Discussion
so the starter motor is turning and the crankshaft is rotating but the point we want (for the spark to fire and the engine to rotate of it's own accord without help of starter motor) is not being reached?
so that sound specifically is what the starter motor makes? If I took the starter motor out and connected the 12V battery to it that's the sound I would hear?
so that sound specifically is what the starter motor makes? If I took the starter motor out and connected the 12V battery to it that's the sound I would hear?
No.
The sound you hear is an amalgamation of the starter motor, the starter pinion on the flywheel ring gear and the engine itself; some low energy suck-squeeze-bang-blow, some engine internals noise and some auxillary components rotating.
I'd say most of the noise is starter pinion on flywheel ring gear.
The sound you hear is an amalgamation of the starter motor, the starter pinion on the flywheel ring gear and the engine itself; some low energy suck-squeeze-bang-blow, some engine internals noise and some auxillary components rotating.
I'd say most of the noise is starter pinion on flywheel ring gear.
Ilovecbrs599999 said:
so the starter motor is turning and the crankshaft is rotating but the point we want (for the spark to fire and the engine to rotate of it's own accord without help of starter motor) is not being reached?
so that sound specifically is what the starter motor makes? If I took the starter motor out and connected the 12V battery to it that's the sound I would hear?
No of course it wouldn't. There is no engine /flywheel being rotated in that scenario is there? so that sound specifically is what the starter motor makes? If I took the starter motor out and connected the 12V battery to it that's the sound I would hear?
<remembers the OP, ah it's the chap who wants a mechanics course! >
Haha with forums like this everywhere on the internet who needs to go on mechanic apprenticeship? 
So the pinion has managed to turn the flywheel a few times and the crankshaft has done some revolutions but it's not going fast enough to become self-sufficient?
Or the pinion just flat out cannot even get the flywheel/crankshaft to even turn?
So the pinion has managed to turn the flywheel a few times and the crankshaft has done some revolutions but it's not going fast enough to become self-sufficient?
Or the pinion just flat out cannot even get the flywheel/crankshaft to even turn?
Edited by Ilovecbrs599999 on Sunday 17th September 07:32
Ilovecbrs599999 said:
Haha with forums like this everywhere on the internet who needs to go on mechanic apprenticeship?
So the pinion has managed to turn the flywheel a few times and the crankshaft has done some revolutions but it's not going fast enough to become self-sufficient?
Or the pinion just flat out cannot even get the flywheel/crankshaft to even turn?
So the pinion has managed to turn the flywheel a few times and the crankshaft has done some revolutions but it's not going fast enough to become self-sufficient?
Or the pinion just flat out cannot even get the flywheel/crankshaft to even turn?
Edited by Ilovecbrs599999 on Sunday 17th September 07:32
Tyre Tread said:
but its not starting for one or more of a possible myriad of reasons
This is why you need to understand how an ICE works.Could be lacks of spark (for a myriad of reasons)
Lack of Fuel ((for a myriad of reasons)
Lack of air ((for a myriad of reasons)
Too much fuel (for a myriad of reasons)
Too much air (for a myriad of reasons)
Things happening in the wrong order
Broken things
Etc etc etc
Ilovecbrs599999 said:
You are trying to start your engine and it 'avin none of it.Ilovecbrs599999 said:
So the pinion has managed to turn the flywheel a few times and the crankshaft has done some revolutions but it's not going fast enough to become self-sufficient?
It is not simply the turning over of the engine fast enough that makes the engine "self-sufficient" you need all parts of the engine to be turning in the correct relationship to each other, sparks to happen & happen at the right time, the correct fuel to go into the engine at the right time in the right amount and none of the above mechanical parts to have gone astray in any way, shape or form.How long have you got?
As said, the starter motor is turning the engine over & IMO plenty fast enough to start the engine.
It relies on fuel delivery & spark occurring at the right moment for the engine to run. Without that you can continue to crank until the cows come home & it won't run. But it could cause damage to the starter motor & wiring due to the excessive overload - if you use jump leads (especially thin cheapies) you may notice how hot they can get.
With modern engines there can be a multitude of reasons for no fuel delivery or no spark & a proper diagnostic with a diagnostic tool specific to the make is the best course of action. A generic code reader may flag up a correct fault code or it may deliver something meaningless.
Is there a problem with your own car - in which case film & put it up - or are you just posting stuff you've found on the internet?
It relies on fuel delivery & spark occurring at the right moment for the engine to run. Without that you can continue to crank until the cows come home & it won't run. But it could cause damage to the starter motor & wiring due to the excessive overload - if you use jump leads (especially thin cheapies) you may notice how hot they can get.
With modern engines there can be a multitude of reasons for no fuel delivery or no spark & a proper diagnostic with a diagnostic tool specific to the make is the best course of action. A generic code reader may flag up a correct fault code or it may deliver something meaningless.
Is there a problem with your own car - in which case film & put it up - or are you just posting stuff you've found on the internet?
You are hearing the engine being 'turned over' by the starter.
The rising and falling speed of the reciprocating parts - the 'duddah-duddah' sound is from the loading within the engine:
Specifically, the loads increase at certain points; the most load occurs during each compression stroke - 1 per cylinder every 2 turns of the crankshaft; on a 4 cylinder that means the will be 4 compression events every 2 turns of the crankshaft. Additional - but much smaller - loads are caused by the cams actuating the valves - as the valves are opened the load increases; as they close, the load decreases.
A basic is that on a 4 stroke engine the cylinder fires once in 2x crankshaft rotations - on multi cylinder engines the same applys - EVERY cylinder fires within that 720 degrees of rotation. For example, on a 4 cylinder: 1 firing stroke every 180 degrees; 6 cylinder: 1 firing stroke every 120 degrees; 8 cylinder: 1 firing stroke every 90 degrees; any guesses for 12 cylinder?
Multi-cylinders smoothes the delivery - as there is less crankshaft speed change in that 720 degrees.
Here's a comparison video (A quick YouTube search away!) On a 4 cylinder engine.
https://youtu.be/F_CxE4RHPTI
Loads of videos on youtube.
If you are looking to learn the basics; buy a copy of 'Hilliers fundamentals'
Once you learn the single cylinder operation adding cylinders, drive types, firing orders is simple.
The rising and falling speed of the reciprocating parts - the 'duddah-duddah' sound is from the loading within the engine:
Specifically, the loads increase at certain points; the most load occurs during each compression stroke - 1 per cylinder every 2 turns of the crankshaft; on a 4 cylinder that means the will be 4 compression events every 2 turns of the crankshaft. Additional - but much smaller - loads are caused by the cams actuating the valves - as the valves are opened the load increases; as they close, the load decreases.
A basic is that on a 4 stroke engine the cylinder fires once in 2x crankshaft rotations - on multi cylinder engines the same applys - EVERY cylinder fires within that 720 degrees of rotation. For example, on a 4 cylinder: 1 firing stroke every 180 degrees; 6 cylinder: 1 firing stroke every 120 degrees; 8 cylinder: 1 firing stroke every 90 degrees; any guesses for 12 cylinder?
Multi-cylinders smoothes the delivery - as there is less crankshaft speed change in that 720 degrees.
Here's a comparison video (A quick YouTube search away!) On a 4 cylinder engine.
https://youtu.be/F_CxE4RHPTI
Loads of videos on youtube.
If you are looking to learn the basics; buy a copy of 'Hilliers fundamentals'
Once you learn the single cylinder operation adding cylinders, drive types, firing orders is simple.
paintman said:
As said, the starter motor is turning the engine over & IMO plenty fast enough to start the engine.
It relies on fuel delivery & spark occurring at the right moment for the engine to run. Without that you can continue to crank until the cows come home & it won't run. ....
It relies on fuel delivery & spark occurring at the right moment for the engine to run. Without that you can continue to crank until the cows come home & it won't run. ....
but what about when it's because you have a FLAT BATTERY? Surely now it's because the pinion isn't turning the flywheel/ it's not cranking fast enough?
Also why is there even a minimum rotational speed for the crankshaft before it becomes self sufficient? I thought that as soon as there's even motion of the pistons there's air intake, ecu sends fuel and the cycle begins (assuming everything else is ok). Why would the pistons going up and down to start everything off need a threshold speed?
HustleRussell said:
Ilovecbrs599999 said:
but what about when it's because you have a FLAT BATTERY? Surely now it's because the pinion isn't turning the flywheel/ it's not cranking fast enough?
Ilovecbrs599999 said:
Also why is there even a minimum rotational speed for the crankshaft before it becomes self sufficient?
Why would the pistons going up and down to start everything off need a threshold speed?
The "pistons going up & down" doesn't "start everything off"
The engine has to be turning to start.
The engine needs the right amount of fuel at the right time.
The engine needs sparks at the right time. (Although we have yet to establish for definite that it is a petrol engine, as you have told us no details of the engine yet, we are all assuming so after last weeks electrical apprenticeship)
It also needs miriad of sensors reading correctly before it will apply afore-mentioned fuel or sparks.
Edited by E-bmw on Sunday 17th September 19:31
Oh woops you're right... that is a different sound with a flat battery: https://www.youtube.com/watch?v=kVyQrQ1aIr4
Ah my bmw friend it is a motorcycle 4 stroke engine apprenticeship as you would have found out if you were patient enough to wait for my new thread on motorcycle ignition...
Ah my bmw friend it is a motorcycle 4 stroke engine apprenticeship as you would have found out if you were patient enough to wait for my new thread on motorcycle ignition...
Ilovecbrs599999 said:
Ah my bmw friend it is a motorcycle 4 stroke engine apprenticeship as you would have found out if you were patient enough to wait for my new thread on motorcycle ignition...
So that begs the question (one of the many that is) why call the thread "car not starting sound"?Gassing Station | Home Mechanics | Top of Page | What's New | My Stuff