2004 envoy 4.2 help me find this noise .

[Ben4.2]

I am trying to find a noise. It is coming from inside the engine but I don't know where, It got new timing chain kits, new rod bearing old rod look fine to me .no metal shaving in oil pan. Flex plate look good no crack new rear main seal .no oil pressure lost engine idle @600 RPM oil pressure 40psi .run drive fine.

 

[Mooseman]

Your posts wound up getting stuck in our spam filter. I deleted the other similar thread you started. If your posts don't appear right away, don't re-post. It will eventually appear. I have no idea why this happened.

Can't access your video. Put the permission as public so you don't have to approve each one of us who want to view it.

Don't rely on the truck's pressure gauge. It's fake. Use a test gauge to verify oil pressure.

What's the mileage? Maybe it's just piston slap.

 

[mrrsm]

A few more Questions...

(1) Did you do this GM 4.2L Engine Repair Work yourself?
(2) Did you Memorialize any of these Repairs in Images/Videos?
(3) If so... Will you link us to that information? It Could prove Helpful.

 

[Ben4.2]

Your posts wound up getting stuck in our spam filter. I deleted the other similar thread you started. If your posts don't appear right away, don't re-post. It will eventually appear. I have no idea why this happened.

Can't access your video. Put the permission as public so you don't have to approve each one of us who want to view it.

Don't rely on the truck's pressure gauge. It's fake. Use a test gauge to verify oil pressure.

What's the mileage? Maybe it's just piston slap.

it 154k miles

 

[Ben4.2]

A few more Questions...

(1) Did you do this GM 4.2L Engine Repair Work yourself?
(2) Did you Memorialize any of these Repairs in Images/Videos?
(3) If so... Will you link us to that information? It Could prove Helpful.

Yes I repair myself I fix the link hope you can see it

 

[mrrsm]

Just for "The Hell Of It"... With the Engine Turned OFF and after EVERYTHING is Ice Cold... Take a Dead-Blow Hammer and Tap very lightly underneath the center of the Stainless Steel CAT Can around the underside of the Catalytic Converter. Listen carefully for ANY Tell-Tail Re-Bound Sounds coming from inside of it.

If you can hear ANY noises similar to "Pocket Change being Dropped into a Ceramic Bowl," sort of sound, it may indicate that the Precious Metal Impregnated Ceramic Honey-Comb hidden inside of the CAT Canister have Fractured and fallen down into the bottom of the S/S CAT Can.

Occasionally, after this damage has occurred, the Rhythmic Engine Vibrations from the Drive Train and those coming from the Exhaust Stream will cause these Engine Sounds and Vibrations to get picked up by the CAT Internals ...and amplified in this manner.

It may be nothing... but it is a fairly painless test to perform as long as you use the Dead-Blow Hammer VERY GENTLY.

 

[Mooseman]

Damn that sounds like rod knock. Could be piston slap. What does the noise do when you rev the engine? Is it the same while driving?

I'd also check the oil pressure with a real pressure gauge.

I know you changed the rod bearings and said they were fine. I wonder if it could be a wrist pin?

Edit: One thing you could do is unplug one coil at a time while it's running to see if you can pinpoint it to one cylinder. If one cylinder the noise changes when you unplug it, that would be the one.

 

[Ben4.2]

Damn that sounds like rod knock. Could be piston slap. What does the noise do when you rev the engine? Is it the same while driving?

I'd also check the oil pressure with a real pressure gauge.

I know you changed the rod bearings and said they were fine. I wonder if it could be a wrist pin?

Edit: One thing you could do is unplug one coil at a time while it's running to see if you can pinpoint it to one cylinder. If one cylinder the noise changes when you unplug it, that would be the one.

Noise is gone when engine rev over 2000 rpm . Like you said I think pistons slap or wrist pin . I did remove 1 piston on cylinder 1 out (check ring to see any oil build up in ring land and wrist pin )but I can not see any wrong I change head gasket set do basic valve job. I upload pics of my old rod bearing sorry I forgot line them up by order 123456.Thanks for help.

 

[Ben4.2]

Just for "The Hell Of It"... With the Engine Turned OFF and after EVERYTHING is Ice Cold... Take a Dead-Blow Hammer and Tap very lightly underneath the center of the Stainless Steel CAT Can around the underside of the Catalytic Converter. Listen carefully for ANY Tell-Tail Re-Bound Sounds coming from inside of it.

If you can hear ANY noises similar to "Pocket Change being Dropped into a Ceramic Bowl," sort of sound, it may indicate that the Precious Metal Impregnated Ceramic Honey-Comb hidden inside of the CAT Canister have Fractured and fallen down into the bottom of the S/S CAT Can.

Occasionally, after this damage has occurred, the Rhythmic Engine Vibrations from the Drive Train and those coming from the Exhaust Stream will cause these Engine Sounds and Vibrations to get picked up by the CAT Internals ...and amplified in this manner.

It may be nothing... but it is a fairly painless test to perform as long as you use the Dead-Blow Hammer VERY GENTLY.

The Cat is aftermarket it look fine inside because I remove it out side.when I change rear main seal.thanks

 

[Mooseman]

So you had the motor basically all apart with the head removed because you had a knocking noise and only pulled one piston out? If I was that deep into it I would have done a partial rebuild by replacing the rings, honing the cylinders and getting the rods and wrist pins checked.

At this point, I would suspect a wrist pin unless oil pressure is low but not low enough to trigger the warning. Remember, that oil pressure gauge is fake.

 

[Ben4.2]

So you had the motor basically all apart with the head removed because you had a knocking noise and only pulled one piston out? If I was that deep into it I would have done a partial rebuild by replacing the rings, honing the cylinders and getting the rods and wrist pins checked.

At this point, I would suspect a wrist pin unless oil pressure is low but not low enough to trigger the warning. Remember, that oil pressure gauge is fake.

this envoy friend give to me with out running ,He told me valve chain make noise. I take home open valve cover I saw a lot oil burn build up inside camshaft wear out. I remove cylinder head out . get one at u pull basic valve job .new timing chain set .start up hear noise .remove oil pan check rod bearing and flex place...…. now wrist pin in my head I never think wrist pin make that noise .don't want pull every thing again to rebuild it. I move on but any way Thanks for help me.