[F1FTY]

Background:

My SS M6 has a Pray ported IM, Katech ported TB and a Rotofab dry CAI.

I've driven on this combo for months now. I've had the Pray IM and ported TB on the car for about a year now. I've autocrossed with it and had fun. I previously had a GM CAI with the tune on the car. When I went to Rotofab, I put the factory tune back on the car.

Issue:

Recently, I took the car out for a drive after it sat for about a week. Startup was normal and so was normal driving. I then gave the car a heavy amount of throttle and heard what sounded like band clamps falling out of the engine bay at the bottom.

I kept driving as no CELs, oil pressure, temp or anything displayed as wrong. The car continued to drive except I lost some power in higher gears (almost like there was a restriction with the throttle). Figuring I popped a leak on the CAI, I was on my way home immediately and the car died out at a red light. It started right back up like nothing happened and I drove the car lightly back home.

I popped the hood and verified that no clamps were missing and that all bolts from the IM to the TB to the CAI were nice and snug. I then pulled up DTCs for the MAP sensor range being low and the circuit being out of range. I replaced the MAP sensor with a brand new one and cleared the DTC codes. There were only two DTCs related to the MAP sensor. I also checked the vacuum at idle and it read 32 kpa so I ruled out any leaks from the IM itself.

Today, with all codes cleared and no leaks I started the car up to take it out again. The idle was a little rough but settled and was smooth from the cold start. I then drove it around and there were no issues while driving it normally. I decided to press my luck and punched it hard. At the very next red light, the car stumbled and died. I then tried to start it back up and the starter motor wasn't able to turn over the engine for much longer than usual and even had a higher pitch squeal to it. Finally, the engine turned over. No CELs this entire time and I drove the car home lightly.

It is now parked and I'm going to go check for DTCs again (Update: no DTCs found). Any ideas of something else I should look for?

[F1FTY]

Car wouldn’t start easily this morning and then the engine began making knocking noises. I’ve pulled it into the garage to check the oil level, put it back to stock and will flatbed it to a dealer. This isn’t normal

[F1FTY]

Pulled intake manifold. Intake port covered in wet oil. Rest are dry. Looks like I got a bad lifter?

[soloknight6]

Ive heard of plenty of lifter issues with these LT1 engines. Sounds like you've found the issue.

[F1FTY]

Originally Posted by soloknight6

Ive heard of plenty of lifter issues with these LT1 engines. Sounds like you've found the issue.

Yeah, I was hoping to be one of the lucky ones but here we are. Hopefully the dealer will be kind to me and cover it. The car is garaged and not beat on by any means.

[soloknight6]

Im sure they will, just take it to a dealer that deals with a high volume of performance cars. They seem to be more helpful than the average ones, especially when it comes to warranty work.

[F1FTY]

Originally Posted by soloknight6

Im sure they will, just take it to a dealer that deals with a high volume of performance cars. They seem to be more helpful than the average ones, especially when it comes to warranty work.

Thank you..my fingers are crossed!

My car has been towed. Not fun watching your car get towed away. The tow scrapped the **** out of the front spoiler. I took pics.

Dealer will open it up tomorrow at 10:30am.

Let the fun begin.

[Krowser]

Originally Posted by F1FTY

Pulled intake manifold. Intake port covered in wet oil. Rest are dry. Looks like I got a bad lifter?

My buddy G2K (Camaro6.com member) had a similar situation:

G2k was on the dyno trying to tune his vehicle when there was a clacking noise coming from the top of the motor on the left side with reduced power. He consulted with Pray and the culprit was:

a bent connecting rod

He had to replace the rocker and connecting rod. When he fired it up, he could still hear the tapping, this time from the left side. So he discovered he had another bent rod. G2K replaced the bad rod on the left and now his car is perfecto mondo!!

[F1FTY]

Originally Posted by Krowser

My buddy G2K (Camaro6.com member) had a similar situation:

G2k was on the dyno trying to tune his vehicle when there was a clacking noise coming from the top of the motor on the left side with reduced power. He consulted with Pray and the culprit was:

a bent connecting rod

He had to replace the rocker and connecting rod. When he fired it up, he could still hear the tapping, this time from the left side. So he discovered he had another bent rod. G2K replaced the bad rod on the left and now his car is perfecto mondo!!

Holy crap.

That’s my fear with this as well, I really hope warranty covers it!

[F1FTY]

Update:

Dealer found a misfire code, inspected the lifters and found that the spark plug electrode in cylinder 8 was bent. They had no idea why or how but replaced the plug and called it fixed.