Greasymechanic

Just bought my first 4th gen engine was blown so I replaced it with a 5.3 noticed a very very very light tap after install on topside of engine thought it was because the motor hadn't been run for awhile and it got worse beings I've dealt with plenty of 5.3s I figured lifter put a whole new set in noise still there figured I may have got a bad lifter from the parts store so I tore it down again and replaced any that seemed questionable but still there and it's driving me crazy I've tried disconnecting coils one by one to see if it's a rod makes no difference only change I've noticed is if I disconnect the #2 injector the sounds still there but slightly less loud it also quiets down after engine gets up to temp at idle but starts getting loud again at anything over 2000rpms and especially loud on deceleration car doesn't seem sluggish or even like it's missing and has no codes just a slightly rough idle anybody got any suggestions right now I'm thinking of doing a complete overhaul but really want it ready for scraping the coast in june

RockinWs6

Might be the oring on the pickup tube leaking air into the oil stream. Will cause lifter tapping AND is quite common if the engine is over 5 years old. I'd try adding a seal sweller like TransX 1st and see if it remedies it.

Greasymechanic

Oil pressure is 60 cold 40 when up to temp and 60 cruising so I wasn't thinking the oil would be a problem

RockinWs6

Pressure has nothing to do with it. You could have 100psi and if the oring is letting air in the lifters are going to tap all day long.

Greasymechanic

Think it would be possible to change it without dropping the sub frame maybe just lower the pan and pull the front cover

RockinWs6

Try what told you 1st, if it fixes it I'd let it alone. Plus you'll know if that's the problem. Mine has been fine for 60k since I used the TransX.

If you can get the oil pan off I'm sure you could change it but I seriously doubt it without lifting the engine sky high. Probably easier to buy a puller, flywheel holding tool and a balancer installer and take the frt cover off. You will still need to drop the oil pan some even that way.

RockinWs6

AND NO THE TRANSX is not going to hurt anything. I've been using it for 30 years in everything you can think of.

Greasymechanic

that's what I meant I was talking bout pulling the front timing cover after removing the balancer

Greasymechanic

Replaced the o ring and its still tapping this is so frustrating been wanting one of these cars for a while and now that i finally got it its been a headache anybody got suggestions on where to get a 5.3 rebuild kit

krismaze

You got a video of it up ?

RockinWs6

Did you check the oil for air bubbles? Did you use the right oring? Did you install it on the pickup tube then install the tube into the pump?