j_bby

i have a 98' ls1 daily driver. it has roughly 155k miles on it.
a few days ago it started making a really loud noise sorta like a tapping noise.
its def coming from the top of the motor.

i have parked the car since it started making the noise.
oil pressure is good...
the knocking does ease up when i push the gas but does not stop even after motor is warm so i dont think it is a piston slap.

any ideas?

R6cowboy

iTrader: (3)

Very possibly a lifter. They can make a loud tapping noise when going bad. All aluminum LS1 motors all of a sudden making a really loud tapping noise is not normal, nor ok.

Edit: I noticed whoever posted before me deleted their very misleading post, which the second sentence of my post was referring to. In case you were wondering why I said that.

j_bby

it's def not normal.. and i noticed a decrease in power...

Snake_Skinner

iTrader: (12)

My really loud tapping noise noise was a failed lifter, really sucked.

R6cowboy

iTrader: (3)

Also could be a broken valve spring perhaps. A couple springs broke in my C5 but the ticking/tapping noise didn't get really loud until higher rpm.

jimmyblue

iTrader: (11)

The needle bearings in the rockers have a habit of
wandering off to the oil pan. If you find them there
then you know what to do.

SSdreamz

iTrader: (3)

pull off the valve covers and look for a puked rocker or broken valve spring(s)

p8ntballkid090

I have the same problem, and pulled the valve covers off today. Replace the pushrods and noticed the rocker arms have some side to side play and diagonal play when holding the stud. I don't know how much play is acceptable.