VTtransam

I had 0 KR after Mike at Rapid tuned my car back in June. I noticed on the dyno that at higher rpms a good bit of black smoke was coming out of the tailpipes. My car is a '99 so I figured I just had the poor ring design, some say it is normal, but it was a good bit of smoke. Also, before I had tuning done I took the heads off to replace the lifters and I noticed oil around the exhuast gaskets.

Now, a couple months after then tune, I'm getting KR. 2.29* of KR at 1840 rpm and it steadily decreases to 0 at 6000 rpm. I have 0 KR at 6000+ rpm. Since the tune I just replaced the oil pump, thats it no other changes. I have TR6's gapped at .050.

I'm wondering if my rings are so bad that the oil in the combustion chamber is causing this knock, my car only has about 25k miles on it. Its not driven daily and isn't abused at the track every weekend.

What should I do?

Matt

qs9999

I am a Pontiac tech who works on Firebirds alot, if you have a 6 speed trans then your car will have that oil problem more than an auto does. but the smoke should be blue not black, if its black then your car is running rich. if its more blue than black then its a 6 speed 5.7l firebird. the knocking noise is most likely from the piston skirt, (another 5.7L problem) most likely on the drivers side and worse at cyl #1 the way to tell if its upper or lower end it to turn off power to the cyl. 1 at a time while running if the noise goes away or goes alot quieter its lower end. (to shut off the cyl you can pull the plug wire, pull the coil wire, unplug the injecter, or get your hands on a tech2 or equal and ture off the injecters that way) if the noise changes then the noise is going to be piston skirt, or rod bearing. sometimes the noise is so bad the test donot help if that happens i just drop the moter and tear it down. but it always tuens out to be the piston skirts but make sure you check your top end first because you put the cam in.

good luck and hope this helps

Ken