My buddy's honda accord (F22A) all of a sudden started making a weird knock-type noise. I rode in her car, and at first, I thought it sounded like a heat-shield or bumper-piece or something under the hood was loose. When she accelerates, it makes a knocking noise. It doesn't drive any differently that it used to.... no power loss, just that damn knocking noise. It started all at once (not gradually) about 100-150 miles ago, and it has not gotten any worse or better since then... sounds the same.

Upon popping the hood, I can't locate anything loose.. it sounds like its coming form inside the motor. As the rpm's rise, it gets worse..... idle is fine. but getting the rpm's up makes it sound pretty bad. I checked the plugs.... they're all good and dry (no oil or fuel). I'm going to perform a compression test tomorow... but I've never heard a knocking engine firsthand, so I can't tell if there's something wrong with her motor, or if its something else (that doesn't require a rebuild)

How could I identify a knocking motor... how should it sound and act? My gut says that's not the problem... but I'm not sure. Any thoughts are appreciated.

 

check th oil did you do that?

 

yeah... oil's good.

 

Have the engine running and take one spark plug wire off. If the knocking nose stops its probably a rod bearing for that cylinder.

 

correct rocket, it could also be a loose timing belt flapping. I am having the
same issue myself. did the ignition check per cyl and then noticed the belt
was loose... it sounds a bit higher and more plasticky than a spun rod-bearing
(been there before on a 91 prelude, the mechanic removed the spark wires and it was cyl #3!) I would check the belt! Be careful checking your compression... get it to normal op temp, plug the throttle open, remove the plugs and crank it by hand.
engine damage can result... comp should build quickly in a healthy motor. if it idles fine and has no real power decrease, you wouldnt need to comp check. if you had uneve compression the idle wouldnt be there, you would know it would sputter and pop at idle and run rough.

good luck!




[Modified by MikeSarr_GSR, 8:43 AM 5/7/2002]

 

Try answering the door, that always seems to get rid of the knocking =x