Engine runs but knocks after high RPMs

[IcedLS]

Hey guys, need some advice.

The 02 LSV6 manual is making a ticking/ knocking noise that follows the rpm.

This happend after pushing the engine to right before red line before shifting into each gear. Once I brought the car to a stop at the lights, it shut down and didn't want to restart. Didn't want to crank, giving the sound of a dead battery crank. Even bump starting did nothing.

Unfortunatly I had to tow it home due to a busy intersection (sad part was that I could see my house from where it broke down, about 150 meters or 0.1 mile).

The next morning, the car started with no resistance in the crank. Makes me think I flooded the engine the day before. Problem was that it now knocks. I'm thinking it's a rod knock as the car is still drivable with no loss of power. Oh and get this; no check engine light.

This happend in October, I've since then had the car parked. It's actually up for sale in the forum. I'm mechanically savy so I thought perhaps I can recover it myself.

Any thoughts what it might be?

 

[AmsterDutch]

Hey guys, need some advice.

The 02 LSV6 manual is making a ticking/ knocking noise that follows the rpm.

This happend after pushing the engine to right before red line before shifting into each gear. Once I brought the car to a stop at the lights, it shut down and didn't want to restart. Didn't want to crank, giving the sound of a dead battery crank. Even bump starting did nothing.

Unfortunatly I had to tow it home due to a busy intersection (sad part was that I could see my house from where it broke down, about 150 meters or 0.1 mile).

The next morning, the car started with no resistance in the crank. Makes me think I flooded the engine the day before. Problem was that it now knocks. I'm thinking it's a rod knock as the car is still drivable with no loss of power. Oh and get this; no check engine light.

This happend in October, I've since then had the car parked. It's actually up for sale in the forum. I'm mechanically savy so I thought perhaps I can recover it myself.

Any thoughts what it might be?

The LS doesn't have lifters but something very similar with just a different named terminology ...if you want to try spraying in a can of Sea foam spray for cleaning lifters and all around engine it's only $9 dollars at most big box name stores Walmart, mills Fleet farm, Home Depot nothing to lose it won't hurt but you may waste $9 dollars if it's truly a Rod knock place nozzle in vacuum line on top of intake manifold it's easier then just follow directions

 

[joegr]

The LS doesn't have lifters but something very similar with just a different named terminology ...if you want to try spraying in a can of Sea foam spray for cleaning lifters ...

The tappets are solid, not hydraulic...

 

[Broseph]

Not sure a sensor would through a code on rod knock. The symptoms you mention sure sounds like rod knock from a possible spun bearing due to redlining the engine. Rod knock is typically most pronounced right after you hit the throttle.

There are a few ways to verify. one involves pushing the piston through the spark plug hole with a screw driver to see if there is play when the piston is at bdc.

 

[IcedLS]

There are a few ways to verify. one involves pushing the piston through the spark plug hole with a screw driver to see if there is play when the piston is at bdc.

I know of this method. I thought it was TDC on its way down when you check for play.

 

[Danny351C]

Glad to hear it still runs buddy! We'll after that beating, change that oil! Add some Lucas Oil treatment. Run about 8 to 10 Oz of MMO in a full tank gas too. Say a prayer. By flooring it to RedLine like that you stirred up something the engine did not like! Its not good to do that and your asking for trouble. Check your plugs for Fouling also chances are they need to be replaced now, especially after all that un-burned fuel cooking on hot plugs. The engine knock sensor, MIGHT throw a code or not. I'm more concerned about your engine internals. Do the oil change.

 

[Jeff M]

Drain the oil into a clean catch pan and check for metal shavings in the oil. Remove the oil filter, cut it open and check for metal shavings in the media as well. If you find metal then that's not a good thing at all but you'll have your answer. Good luck with it and bringing a motor to redline doesn't hurt at all if the motor is healthy in the first place. Bouncing a motor off the rev limiter is a fairly common practice in autocross, done it many times in my Trans AM, and I've done it in the LS numerous times playing around manually shifting it on the street.

 

[Danny351C]

Drain the oil into a clean catch pan and check for metal shavings in the oil. Remove the oil filter, cut it open and check for metal shavings in the media as well. If you find metal then that's not a good thing at all but you'll have your answer. Good luck with it and bringing a motor to redline doesn't hurt at all if the motor is healthy in the first place. Bouncing a motor off the rev limiter is a fairly common practice in autocross, done it many times in my Trans AM, and I've done it in the LS numerous times playing around manually shifting it on the street.

Hi good buddy. Good idea about suggesting to inspect the filter media. Ive played around too with cars and trucks and raced in the past. I like to get on my DD too now and again. I try not to push it. In terms of a car that's a daily driver, its not a good practice to hammer on it too much. Unless you have a fat wallet for repairs, a back up ride/wife to get to work and a very understanding boss...I still say its risky. lol. Be well.

 

[Broseph]

Drain the oil into a clean catch pan and check for metal shavings in the oil. Remove the oil filter, cut it open and check for metal shavings in the media as well. If you find metal then that's not a good thing at all but you'll have your answer. Good luck with it and bringing a motor to redline doesn't hurt at all if the motor is healthy in the first place. Bouncing a motor off the rev limiter is a fairly common practice in autocross, done it many times in my Trans AM, and I've done it in the LS numerous times playing around manually shifting it on the street.

I’m curious how this is done. I was concerned about a spun bearing before so cut open the filter. However, cutting the filter created metal shavings as well. Soooo, how do you tell between the two (bearing vs cutting filter shavings)?

 

[Danny351C]

I’m curious how this is done. I was concerned about a spun bearing before so cut open the filter. However, cutting the filter created metal shavings as well. Soooo, how do you tell between the two (bearing vs cutting filter shavings)?

Thats a great question!
Ideally a large pipe cutter would minimize shavings. Ive used an Awl and tin snips to cut the filter case open near the bottom. Its very thin sheet metal. Inspect within the filter media.