8.1 engine knock or something else?
 

2003 2500 suburban lt 8.1

The ongoing saga..

The oil line to the radiator blew and I loss all pressure(and oil all of it). Oil was everywhere!!!

The ecu shut down the car.

After fixing the line and replacing the oil it started up hesitantly at first but then came back to life..everything was fine..for about 2 miles then a small knock started happening. I turned around and headed home.

The engine starts and idles perfectly and is not overheating.

When you give it gas however at idle or in drive I can here the knock.

thoughts on where to start?

1. I've heard bad exhaust gasket or exhaust bolt could make similar noise.
2. heard bad cat could make similar sound?
3. pull valve covers and look at guides? What am I looking for?
4. Drop pan and look for shavings? Hopefully not a lower bearing?

Thanks for any advice.

I went and listed it for sale as a parts car. I was so done with it at the time but now rethinking it. I love that burb..well love hate...

I can post a video up if that would help

Re: 8.1 engine knock or something else?
 

A video would help.
Rod knocks are a very distinctive noise.
Loose Torque converter bolts can mimic a rod knock. Not much else I can think of.
Exhaust leaks don't quite sound the same.
Broken rocker arms on a smallblock kinda sound similar til you get the stethoscope out and discover it's coming from up top.

If it's wiped a rod bearing or two you'll usually see the teltale glitter in the oil when you drain it into a catch pan. Kindof a sinking feeling in the pit of your stomach when you see that glitter in the oil.

Re: 8.1 engine knock or something else?
 

I'll load 2 video links one at idle where there is no noise and one after about 10 or so seconds. For the first few moments it makes no sound even when I rev the engine..sounds great and gets my hopes up and then the noise on the second video starts.

https://www.youtube.com/watch?v=Y9VTDFQsMqo
https://www.youtube.com/watch?v=z9rqfFalC78

thanks

Re: 8.1 engine knock or something else?
 

Your videos are marked private.
You must've missed a setting somewhere.

Re: 8.1 engine knock or something else?
 

I fixed it should be public now

Re: 8.1 engine knock or something else?
 

ok now its searchable and viewable on youtbe..man that was a tutorial on youtube for 30 mins

Re: 8.1 engine knock or something else?
 

A rod knock should be more pronounced and rhythmic. Not saying it's not but I'd start looking for loose stuff.
If it is the beginnings of a rod knock it will get progressively worse.

If you wiped out some rod bearings the oil pressure will probably be lower than it was before.

You can drain your oil and look for the teltale glitter of wiped bearings.
You can also cut an oil filter open with a big pipe cutter. Opening them up with other tools can leave shavings behind. Pipe cutters or oil filter cutters cut through with sharp wheels unlike a die grinder or hacksaw.
I have an old 4 wheel Ridgid 44S I picked up at a yard sale for cutting open spin on oil filters.

Re: 8.1 engine knock or something else?
 

its eaither a rod or a cracked flex plate if it only startted after loosing an oil line id say rod