Have a 99 SS that has a bad engine knock, not sure if it's the lifters or ??
I have been seeing that this seems to be a common problem, any suggestions.

Car has about 105K on it. I'm have it transport up to me from Florida, was worried to continue driving , didn't want to cause more damage.

If its a lifter problem or a rod bearing problem, is it a big fix?
The more you give gas, the less the knocking noise gets. Its worse at idle.Sounds like two metal pipes hitting eachother.
Can it be the cam?
Thanks for any help.

 

My knocking noise was 2 spun rod bearings. Mine is a 98 though. But good luck anyway.

 

The 2 most common sources of noise are lifters and rod bearings. Valvetrain noises make more a tap noise, while rod bearing make a knocking noise. Post a video of the noise.

 

Will do once I get it back home. I didn't want to drive. Is this a costly repair?

 

It is difficult to diagnose these noises not being able to actually hear them. You can also get noises for the accessories being driven by the belt. You can easily diagnose this by removing the belt and starting the car for a short period. The next thing to do is take a hose and place one end at your ear and the other end on various parts of your engine. Good luck.

 

Take a long screwdriver and put it just above the oilpan on the side of the block. Hold the other end to your ear. If everything sounds smooth then it's not a rod knock. (which is good).

Lifter noise and piston slap are common on these engines.

Does it go away after the oil warms up to temp (5 or so minutes) ???

Mine has some piston slap that I swore was a lifter or something in the valvetrain, but after getting to temp it's fine. I was worrying over nothing.

 

It happen right when I started it the other day, I quickly turned it off. I waited a bit a started it agian, and it still did it, so I was worried to do damage so I didn't try again.I never got the engine up to temp. Now I am having it transported home to see whats wrong.Thanks

 

hows oil pressure?

 

Oil pressure is fine, oil is clean,etc... I'm have been asking around and few people are telling me that it can also be the cam? It's driving me crazy what it can be. If its the rod bearing , aren't I better off switching out the motor than doing a rebuild?

 

yes. definitely. I just went through rebuild options and settled on a 408 stroker LQ9 kit from texas speed. It was around 2900 total delivered, i swapped out heads, cam, and ported oil pump, and bought new lifters and timing chain. Now I'm waiting for june 6th to get it dyno tuned. In the end it was about 3800 out of my pocket plus 600 dollar tune, but well worth it.

 

I thinking that this will be the best option, if the rods are screwed. I found GM Grate engines with GM warranty for about 3100$.

 

Chrome, I was just searching for a similar (same?) problem... a knocking (or tapping) sound coming from the top (I think) of my girl's 3.8L.
It *does* go away after the engine warms up and only happens when it is cold. What does that usually mean? And what do you mean "piston slap"? The piston hitting the valves?

 

piston slap is when the pistons are smaller than the cylinder bore and it rattles back and forth till it gets up to temp and everything exspands do to heat making it tighter in the bore

 

I can't believe that's still quoted...