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View Full Version : Why does a car sound like that when it starts?



Atlblkz06
12-15-2008, 11:54 PM
Well the title says it all.

I've been thinking about it for a long time now - nothing in an engine, or the starter should make it make that typical noise when it starts. Hybrids are near silent when they start (even when stationary).

Since it cant be the actual engine (which is entirely silent except for the air noises) - its got to be the starter. Since the starter RPM goes up and down depending on load - maybe thats the repeating noise that sounds like mechanical scratching?

http://www.youtube.com/watch?v=Y2ffO7JXXnA&feature=related

STRteg
12-16-2008, 02:13 AM
Well the title says it all.

I've been thinking about it for a long time now - nothing in an engine, or the starter should make it make that typical noise when it starts. Hybrids are near silent when they start (even when stationary).

Since it cant be the actual engine (which is entirely silent except for the air noises) - its got to be the starter. Since the starter RPM goes up and down depending on load - maybe thats the repeating noise that sounds like mechanical scratching?

http://www.youtube.com/watch?v=Y2ffO7JXXnA&feature=related

:thinking::thinking::thinking::thinking:

Barefoot
12-16-2008, 05:05 AM
not worth the time to answer

dabuilding
12-16-2008, 10:56 AM
alot of that is the blower blades but u hear individual firing because its starting the rpms r not high at all

h22ek
12-16-2008, 04:29 PM
........?

mirz833
12-16-2008, 04:34 PM
im lost:thinking:

AlliRae
12-16-2008, 04:44 PM
.... you really have a transformer... better watch out.

Halfwit
12-16-2008, 05:48 PM
why is sky blue?
why is tree blue?
how does posi-trak on a plymouth work?

some things you jsut have to accept, and move on.

STRteg
12-16-2008, 07:01 PM
why is sky blue?
why is tree blue?
how does posi-trak on a plymouth work?

some things you jsut have to accept, and move on.

:lmfao: :taun:

Atlblkz06
12-16-2008, 09:01 PM
why is sky blue?
why is tree blue?
how does posi-trak on a plymouth work?

I know why the sky is blue, I don't know of any blue trees, and I know how a Posi-Trac works.


some things you jsut have to accept, and move on.

That's exactly where I disagree 100%. :cheers:

STRteg
12-16-2008, 09:04 PM
Snaps!

EmminoDaGreat
12-16-2008, 09:22 PM
deertay joe.

Echonova
12-16-2008, 10:00 PM
Well the title says it all.

I've been thinking about it for a long time now - nothing in an engine, or the starter should make it make that typical noise when it starts. Hybrids are near silent when they start (even when stationary).

Since it cant be the actual engine (which is entirely silent except for the air noises) - its got to be the starter. Since the starter RPM goes up and down depending on load - maybe thats the repeating noise that sounds like mechanical scratching?

http://www.youtube.com/watch?v=Y2ffO7JXXnA&feature=relatedAlot of hybrids also benifit from newer technology. The way I understand it that some (not all) hybrids will stop when the number 4 cylinder (assuming it's a 4-banger) is in the compression stroke. To start moving again when you press the pedal the computer fires the #4 spark plug and opens the injector to only the #1 cylinder adding fuel to compress on it's upward stroke, #1 fires and the engine comes to life like you push started it.

Atlblkz06
12-16-2008, 10:26 PM
Alot of hybrids also benifit from newer technology. The way I understand it that some (not all) hybrids will stop when the number 4 cylinder (assuming it's a 4-banger) is in the compression stroke. To start moving again when you press the pedal the computer fires the #4 spark plug and opens the injector to only the #1 cylinder adding fuel to compress on it's upward stroke, #1 fires and the engine comes to life like you push started it.

I've never heard that one before, but it makes sense. I do own a hybrid, I wonder if there is a way I can confirm this. The car is an 09 Camry Hybrid.

When the car is "idling" with the motor off and the battery runs low, the engine will kick in for a minute or two to recharge. There is a very distinct jerk (no starter noise, or any electrical whirring) which confirms your theory. I wonder how its able to stop the crank at a precise location like that though.

STRteg
12-16-2008, 11:01 PM
I've never heard that one before, but it makes sense. I do own a hybrid, I wonder if there is a way I can confirm this. The car is an 09 Camry Hybrid.

When the car is "idling" with the motor off and the battery runs low, the engine will kick in for a minute or two to recharge. There is a very distinct jerk (no starter noise, or any electrical whirring) which confirms your theory. I wonder how its able to stop the crank at a precise location like that though.

All done by smart a$$ computers:bump: