knocking sound

[chr1s11575stang]

1990 gt original 302 with 89k miles no upgrades only thing is smog pump is off and cat converters. Its been running perfect as of late and I put gas in yesterday then drove it home. Started it this morning and in the way to work a knocking noise started, souds like its coming from the drivers side....What could this problem be or where can I start? oh yeah also there is no loss of power or any other problems

 

[ShortThrow50]

rod bearing?

 

[fford]

could be a rod bearing, main bearing or wrist pin if it sounds like it is from the bottom end. Does it knock at idle, during acceleration or decleration?

 

[chr1s11575stang]

it knocks at all times so far it just speeds up and slows down according to my acceleration

 

[fford]

does it sound like it is bottom end? Or is it possible it is in the head area? It could even be an accessory bearing on the front of the motor.

 

[illedran]

My 92 was making a knocking sound from under it.Turned out a bad baffle in muffler.I will just throw that out there.

 

[chr1s11575stang]

when i got home last night i listened everywhere and it sounds like its coming from the top near the valve cover on the drivers side. i checked all the exhaust and it does seem to be tight...could it just need new gaskets? oh and also this morning it seems whenever i came to a light or slowed down the oil pressure would drop

 

[MikeROD16]

check your rockers. I had roller rockers installed on my gt and they came loose once.

 

[Dino Dino Bambino]

oh and also this morning it seems whenever i came to a light or slowed down the oil pressure would drop

That does sound like a rod bearing. Pull the plug wires one at a time while the engine's idling (wear thick rubber gloves so you don't have an electrifying experience ). If the knocking sound diminishes or goes away altogether, you've found the cylinder that has the bad rod bearing.

 

[MikeROD16]

true, i didnt see the oil drop part. sorry lol

 

[v8only]

grab a long screwdriver, use it as a stethascope. with the engine running CAREFULLY touch it to spots on the oil pan and the plastic end to your ear, and if nothing then to the valve cover. you'll be able to identify exactly if it is an internal problem, if it's coming from the top or bottom, and even which cyulinder

 

[chr1s11575stang]

ok i will try all that when I get home tonight. also im thinkin I might change out all the exhaust while im at it cuz I found out last night its got leaks what would be the best headers and exhaust to put on? what sounds the best?