Need your opinions

[TDH]

I need your guesses as to what is causing this knocking noise in my 1998 Grand Am. It has 208,000 miles on it now, but it doesn't burn any oil and still runs strong. I first started noticing the noise 2 winters ago and it has gotten gradually louder since then. It doesn't seem to get any louder or quieter when driving but it is getting a little embarrassing driving a car that sounds like it going to blow up at any second.

[Jeremy airjer W]

Sounds like a rod knock. with that many miles run it till it blows! You might be surprised how log it will go!!

[katophil]

piston slap a lot of them did it.

[Jeremy airjer W]

piston slap a lot of them did it.

Not that loud! Piston slap usually occurs with a cold engine and goes away after the engine has warmed up.

[blakeb]

not piston slap, it goes away with the expanding metal.

dont sound like a lifter but pulling off a valve cover will give you an idea of rocker arm condition,.

[Deershooter]

i agree that it is piston slap. I just replaced my cousin's motor with the same symptoms. We had no idea what the problem was so when I had it out I ripped it apart and found that 2 of the pistons and cylinders where noticeably warn. After that I talked to a guy at the machine shop I go to and he said it was a very common problem.

[MNice]

Sure it ain't a diesel??

[Big Buck Buster]

It sure sounds like you have a collapsed lifter. Push rods that loose will make a heck of a knock. Pull the intake, and you will see if any lifters are collapsed. At this point, a sea foam treatment won't help. Replace all the lifters while you are in there. Prime the lifters before you put them in.

BBB