2.4 engine knock sound...

[AeR0]

ok so here is my problem.. when my car is at a deadstop i have a problem with my car misfiring cylinder # 2 only.


but my major concern is when i am on the gas lightly i can hear this knock sound? but it goes away as the car accellerates.. if i floor it the sound does not get louder?


anyone know what my problem might be?

[rixGAphx]

When taling about cars, 'knock sound' is confusing.

There is the 'layman's' term 'knock', referring to something like a person knocking on a wood front door with his knuckles.

Then there is the 'mechanic's' term 'knock', which referes to a specific kind of misfiring condition.
In the 'old days' of '30's - 50's cars, it actaully was bad enough that it sounded like somebody knocking on a door.
Nowadays, it sounds more like a series of 'pings', like slightly metallic sounds of bells.

First, you need to get that misfiring #2 cylinder fixed; possibly a bad injector or plug or plug boot.

Second, have an experienced mechanic listen to the 'knock' sound.
I doubt that it's 'engine knock', since that's very rare and the GA engines have 'knock sensors' to prevent it.
Might be 'piston slap', which is strongest when the engine is cold and diminishes strongly or totally as the engine warms; this is a problem to some degree with most engines, though it's noisest on cheaper american engines like the Pontiac line. Nothing you can do but rebuild the engine with new pistons, or live with it.

Might be sticky valve lifter.
but I don't know anything about the 2.4's valve train, so somebody else will have to jump this question.

Same relative to the timing chain and gears, though they rarely make a 'knocking' sound; more like 'clatter' or 'whirring'.

Hope this helps,
-Rick