Sudden Loud knocking
 

Just posted this on LS1Tech, looking for other opinions here:

Hello all-

Driving home today, the car suddenly began knocking very loudly. I then limped my car home as I was less than a mile away. The noise is rhythmic and the speed increases with the throttle. The knock can be felt in the tunnel and by the firewall. I initially suspected a problem with the clutch and flywheel, but after some searching, I'm beginning to suspect a failed lifter or some sort of major failure in the engine. The engine still has oil.

If I were to remove the oil filter and cut it open, is there anything I could look for to tell if the problem is in the engine? My reason being, if the problem is engine related, I will likely just park the car until I can afford a new motor. If it isn't, I will just fix it now. I don't have the room or the know-how to remove and rip apart the motor.

Thank you guys in advance.

Jacob

I would drop the oil too into a clean bucket/pan, take picture with a flash,should be able to see if its got a lot of metal in it.
post picture up.
Using a paint screen or the like while draining to catch any large metal fragments and such is a good idea too.
let me know what you find.

Im guessing rod bearings

Thanks. That makes sense. I'm going to do that first thing tomorrow. I don't have a paint screen though, so I'll just fish around in there with my hands. The engine was rebuilt less than 15k miles ago by the now defunct TTP. I sure hope it isn't the rod bearings.

If its anything in the motor, Matt from TTP now works at ECS

Are you implying, that he is gonna "make good" or "help him out"? Cuz I can almost 99% guarantee he won't. Dude is outa business for a reason, don't know what it is but I'm sure its a good one.

I am in no way downing him, just stating facts of life.

Jake, if there is something wrong w/engine, I can take care of ya. I've done a few LS motors in my day:scratch: I just did Chris's (njtorque) vert, basicaly the whole car....lol

Just curious, does the oil pressure gauge do anything funky?

Curt- Thanks for the offer. I means alot to me. I am not sure what I will do if it is the engine. I've wanted a new build for a while now, but the timing isn't good. If I do decide to tear into the car myself, I'll be needing a huge amount of help. And I agree, Matt owes me absolutely nothing at this point, and if I'm honest, I'd rather him not be near my car ever again. Josh already did a tremendous amount of work to correct their mistakes after TTP rebuilt my engine.

No the oil pressure was right where it normally was. As was the temps. Come to think of it though, the car didn't turn over as it normally does and needed some throttle to start after I pulled over to check the car out. Ugh, motor is toast. Definitely. I'll confirm it when I drain the oil tomorrow.

Sounds like a spun bearing.

I just don't get how it happened. There is sufficient oil in the car, it was holding normal pressure, and the motor had low miles since the rebuild. I do drive the car hard, but nothing to warrant the engine to die so quick.

All it takes is one little piece of metal from a faulty / broken part somewhere, and once that one little piece finds it's way into one bearing the countdown to total destruction begins.

- Justin

I suppose. That was the same issue with the first time the engine went. Over-ported head failed and took the motor with it. Oh well. It is what it is.

Anyways, I did some searching and this is what I came up with. If there is bronze flakes in the oil, it's a bearing of some sort. If its metal sticking to the plug and in the filter, it could be anything else.

Could be **** bearings too. Or a mistake on the builders part. **** happens. Build it bigger next time :)

can you hear the knock when the car is ideling? I have a stethsacope if you want to borrow it. If you have a timing light you can listen for the knock as you point the light on the balancer. If it knocks at every strobe flash you can safley say its an issue with the rotating assembly. If it knocks every other flash Id bet is in the valve train.

The knock can be heard from the next block down. It is incredibly loud. It overpowers the exhaust even.

sounds like what my motor did when it went, i spun a bearing and it was making that sound:| sorry to hear man, if you decide to tear into it ill be down to lend a hand or two. even if something had debris on it when the motor was put together and it finally dislodged itself if it got between the bearing and cam/crank its going to spin a bearing just because your dealing with clearances of 1000's of an inch.

Alright gurus of NJFBOA. Firstly, thank you for all your help. In my attempts to act cool and collected about all this, I've actually been freaking out as this has come at a time when I have just started applying to jobs, and the prospects are looking bleak.

Anyways, I drained the oil, and this is what I found:

The drain plug:
https://lh5.googleusercontent.com/-B...102_120242.jpg
The drain plug indoors. Looks good to me:
https://lh3.googleusercontent.com/-8...102_121434.jpg
There was a tremendous amount of oily crap in my engine bay. I traced it to a leaky power steering hose. I didn't realize it was getting this bad. I doubt it affected anything though.
https://lh5.googleusercontent.com/-T...102_120340.jpg
Now the oil. What am I supposed to be looking for?
https://lh3.googleusercontent.com/-B...102_125848.jpg
https://lh5.googleusercontent.com/-q...102_125917.jpg
Weird bubbles.
https://lh4.googleusercontent.com/-3...102_125905.jpg

At this point, I should admit, I've never really analyzed my oil before, so I don't know what to be looking for. I saved the oil and the oil filter (which I may cut up later if need be) in case I should be reanalyzing but as far as I can tell, the oil looks black and I see no bronze flakes or metal stuff. Or am I not looking closely enough?

Sounds like when my crank went. Did you re-use the stock crank when you had it rebuilt? Could you see the belt tensioner or balancer move with every knock?

You may not find anything in the oil but that doesn't mean you still didn't spin a bearing.
Could also be a dead cylinder. When you said they rebuilt the motor what did they do?

I will also lend a helping hand if needed.

Youtube rod knock etc and see if it compares to what you hear.

Thanks for the offer. I have to look around later for the invoice. I know I have it somewhere, but I wasn't able to find it when I looked quickly earlier.

I youtubed LS1 rod knock, spun bearing, and collapsed lifter. They all sounded pretty much the same to me. The spun bearing, if anything, was the closest: http://www.youtube.com/watch?v=iT4mQa8_YH0

I'm a little surprised that there isn't any noticeable debris in the oil if it really is knocking that loud. I have only grenaded one engine in my life (the 2.8 in my '85 Camaro), and when I drained the oil it looked like paint from an 80's pro street car. After lowering the pan we discovered that the #4 rod bearing had been completely torn up and there was no part of it left on the rod / crank (keep in mind, the car was still running and drivable at this point, but there was a very noticeable lack of power (no v6 jokes). I had been driving it with the rod knock for a few months and was shocked that it held together.

I don't have much LS1 experience, but if it really is knocking that loud, I would definitely assume it's the glorious sound of a rod bouncing on the crank.

- Justin

shine light on it as your pouring it into another container to see any mettalic speckles in the oil.
also you might not see contaminents cus may be traped in filter as that is what its job is for. cut filter open.

other thing I have seen is ringlands breaking which usually shoots out the exhaust so you will not see metal but will get a bad knocking sound,
do the above, if no metal found in pan/filter, than most likely a broken piston, broken ringland etc...

Would a compression test show a broken ringland/piston. ?

Is it really that unlikely that the problem isn't in the engine? Could it be a bolt that backed out of the flywheel for example? is that even possible? I'm so lost.

does your family have a trusted shop they go to?