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engine knock


mattd

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I've been reading the archives looking for any info on engine knock cause the last few weeks i've been hearing a knocking noise. It only happens when the engine is fully warmed up and it sits at an intersection for a minute or so...and when the light turns green and I go to pull away I hear this quick pinging knocking sound a quick three times or so. It never happens when driving even at WOT, or going up a hill. Just at intersections. I've tried using 94 octane gas without any improvement...I also noticed that I have a rattle of some sort, I think it might be a heat shield...could that be it, could a heat sheild sound like engine knock? Any opinions are highly welcomed. Thank you in advance.

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I'm no expert, but I know from experience that a loose part here or there can cause all kinds of weird noises. Almost replaced a transmission once because a heat shield was loose. You'd have sworn it was tranny related. Go figure. :rolleyes:

Fred

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Check the air filter. If it's dirty, replace it. I had a knocking problem until I replaced the air filter. My Northstar used to knock on starts and during acceleration. Since replacing the filter, so far no more knocking.

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I would think this engine would have similar characteristics as the 4.6 engine. Excessive carbon buildup in the combustion chamber;thus raising the compression ratio and making it prone to pre-ignition. Typically by not "exercising it on a regular basis.

Do you give it WOT on occasion?

Allow it to decelerate from highway speeds, to help keep the rings loosened up?

Are the plugs free of any buildup that might cause pre-ignition?

-George

Drive'em like you own 'em. - ....................04 DTS............................

DTS_Signature.jpg

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