Hey guys, I was driving around a couple weeks ago on a dry sunny day in my 99 LS1 Camaro and did a first gear pull, afterwards I noticed the car was knocking horrendously and was running poorly. I found a place to pull over as soon as I could and the car stalled out before I could even cut it. I waited a while and the car didn't want to start, after it fired up it was still running really choppy and stalled out again after only a few seconds. I got a tow truck, was barely able to drive it on the flatbed, but managed then killed it quick. The check engine light never came on and I didn't see any codes. The first thing I did was replace the crank position sensor, but the problem persists. It doesn't sound as choppy, but it still stalled as shown in the video below. Next, I pulled the spark plugs. They pretty much all looked the same, electrodes intact, a bit of moisture on them, smelled like fuel. I then removed the valve covers and inspected the valvetrain. I didn't see any broken springs, the rockers seemed tight, I didn't get around to pulling them and inspecting the rods. The passenger's side appeared perfect, but the driver's side had some coating on the rockers which can be seen below. I drained the oil and looked for any metal shavings or particles in it, there were some things on the very bottom of the drain bucket, but there weren't many and I couldn't really tell if it was anything abnormal, pic below (they look bigger in the pic than to the naked eye). The magnetic drain plug didn't have excessive metal or large shavings on it, just the normal amount. Oil level was normal, about 5.5 quarts, changed only about 1,500 miles ago. I didn't see any fine metallic particles at that point. However, after transferring it to be disposed of, I noticed some more oil in the old oil filter and examined it separately in the bucket at the end, I did notice some fine metallic particles in there. I posted a video of it under a bright flashlight. I'm thinking it's a spun bearing unfortunately, but not sure, I've never encountered this problem before. Should I replace the cam position sensor and knock sensors next? I appreciate any thoughts or suggestions.

This is the video of the sound, it's after replacing the crank position sensor. My father was in the car, but didn't cut it, it stalled. Oil pressure stayed steady slightly above 40 psi the whole time. Sorry it's shaky, I was trying to hear which side it's coming from, but I couldn't tell and didn't want to start it again:

youtube.com/watch?v=KtSBnmWO8IE

This video is of some of the oil from the oil filter:

youtube.com/watch?v=IlKFhO_6vJ0

All the pics:

 

Rod..

 

That's what I was afraid of.

 

On the bright side it could be a fun father son engine swap/upgrade

 

lol that's a nice thought, but I don't think he'd be interested in working on an engine swap. I might do an LQ9 swap or maybe sell it, I've owned it over 12 years. I haven't decided yet.

 

Likely a spun bearing—metal in oil, knocking, and stalling all point to bottom-end failure. Skip the sensors, time to pull the motor.

 

Agreed. I just didn't want to believe I'd have a catastrophic failure like this at under 79k miles with good maintenance. Thanks for the reply.

 

Got an update. I pulled the intake manifold today and discovered a piece of the aluminum broke off the intake and would've had nowhere to go except into the engine. I used a bore scope and looked through the spark plug hole on that cylinder, I'm unable to see the entire piston with it though, maybe 2/3 of it. I can't angle the camera down enough to see the entire surface and the piston is already at the lowest possible position. Unless anyone has any ideas, I guess I'll pull the head and see if that chunk is in there, which I'm hoping is all it is, if not it probably created fine particles which then contaminated my oil and caused a spun bearing. Could something that big be in there long enough without me noticing though? You would think you could definitely hear something of that size in the cylinder.

 

Sucks about the aluminum intake breaking, haven't seen that one.
really need to get the bore scope to show the entire top of the cylinder.
The stalling could be from the massive vaccum leak but that knock is rough.

 

I couldn't believe it just broke off like that, low quality crappy casting. I did notice the metal seemed a bit thinner there compared to the other ports, but never thought it would be problematic, just figured it was the design. I forgot my bore scope came with an attachable mirror, so I'll go out there again tomorrow and see if I can get a view of the blind side. I can only hope the knock is coming from the piece bouncing around in there and like you said, the vacuum leak causing the stalling.

 

If that piece isnt stuck in the top of the piston or the bottom of the head, then that knock would either be a bent rod or spun bearing from compressing the metal chunk.
Even if there are no witness marks on the piston you could still spin that cylinder to TDC once you get the head off and measure the deck clearance to see if that piston is sitting lower than the others, if so it would indicate a bent rod.

 

That's a great idea, I'll pick up a base and dial indicator to check the piston next. I appreciate the suggestion.

 

From the looks of that port on the intake and the condition of the seal, it would appear it was damaged there before or during the install and was about to give up for a while and finally did. Surprised it was running well up to this point, you should have had a good sized vacuum leak even before recently. There is nothing in that area that would have mechanically done that damage.

It might be time to invest in an articulating endoscope. Vevor makes a nice one that isn't horribly expensive. They call it a steering endoscope.

https://www.ebay.com/itm/26716590654...Bk9SR5rRjIToZQ

 

It seemed to be running fine, strong, no problems until it broke off. I've had it on the car 10 years now and close to 40k miles, I don't remember seeing anything unusual with it before installation, but I could just be forgetting since it's been so long. I just bought my current endoscope within the last couple years, wish I would've known about a better one like that. With the way our plugs are oriented, that's really the only way to go. Like you said, the price isn't horrible either.