engine knocking

If it is knocking and no oil up top put a pressure gauge on it and see what it shows. The 5.3 oils the top end first so if there is no oil there it is not getting anywhere else. Could be sludge blocking the oil pick-up, scored pump or blockage farther in the oil circuit. If it has been run that way very long it will probably be a rebuild or replace type repair.

Truck backfires misses and knocks.

Good morning.

The first thing I would do is remove the valve covers and inspect the rocker arms. Sounds like you have a broken rocker arm. Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

Roy

my engine just started knocking. when its cold the engine knocks quiet but as it warms up and gets hot it knocks loud. the oil pressure is low at a stop and it knocks loud and sputters a little. really slow and chugs when accelerating but the knock quiets down a little when driving but its still there and the oil pressure is normal. it sounds like its coming from the drivers side.

So is question to rebuild or replacement engine?

repair if possible and not too expensive

2 ways to do this, if it's a rod knock you can replace theengien with a rebuilt unit, or replace with what's called a crank kit that gives you a crank and all the bearings. However if any rods have had the bearing spin in them then those will have to be taken out and fixed. It depends on the damage. A good thing to test is on a small block with the engine not running, try to push the crank at teh balancer forward or backward with the belts off. If it moves far like a 1/8inch then your thrust is shot on the crank and that will need tobe redone. this is quite common on a small block. good luck.

My old chevy suddenly started knocking and missing under drivetrain load. I suspected I lost a bearing and the a rod is knocking but, I have good oil pressure and it doesn't knock all the time. It does seem to miss though. I changed the plugs and wires (two were burned through) and it didn't seem to help. I thought a rod would knock all the time and you would loose oil pressure if it was bad. I changed the ignition all the way down to the cam a couple years ago. I have yet to pull the distributer to check it which I am going to do next. Any ideas would be appreciated. Thank You.

Could be spark knock try cleaning out the EGR valve and see what happens or the gas octane you're using

the way i test for a bad rod is to idle the engine and apply foot to the break and while doing this gentlly apply a llittle gas putting the engine under a load. my truck had this issue and ended up being loose trans bolts and a broken torque converter bolt and two loose bolts.the miss i cant explain.

the miss might be a little vacuum leak on the manifold or related lines.

This is a rebuilt 350. The motor has a knock at idle but goes away after a slight increase in rpm. The rebuild job has about 40000 miles on it. Does not sound like an exhaust leak. The oil pressure gage does not work

If the knocking noise is coming from the lower end could be rod or main bearings, at upper could valve lash-lifters, wrist pin or rings

thanks

The engine started knocking, I changed the oil and filter and it is still knocking. What else could it be? If it has oil and is not a rod.

could be carbon on piston, piston, rod, main etc. try pulling plug wires one at a time to see if knock goes away if it does then that is the cylinder to hone in on. If it stops it's either a rod bearing or piston problem.