random engine knock

[F1vel66a]

I replaced my driver side head on my 5.4l Triton in my 98 expy I had no knock prior replaced due to broken spark plug hole. Now I have a random knock thzt sounds as if is coming from the intake. It seems to happen more or less after the engine is hot and driving for a few hours. Cohld this be from a under tourqued head (50 ft lbs) over tourgued cam guids? I used all the parts except valves from my old head. I wax thinking timing chain at first but it seems to be that would be Almost all the time not after extended trips. Also if I let it sit for a hour or so the knock goes away. I have 10x30 oil in it but it started with 5x20. It speeds up with RPMs and slows down almost as if it was timed to the engine. Cel codes are p0171 & p0174 banks to lean (got a cracked vacuum line fixing it today) anyways any help would be appreciated

 

[toms89]

I hope you followed the factory torque specifications ?! This is critical in order to maintain proper seal.

Head bolts

Step 1 - 30 lb ft.
Step 2 - tighten an additional 90 degrees
Step 3 - tighten an additional 90 degrees

They are tightened in a criss cross pattern from the center out.

The head bolts are torque to yield so should not be re-used. (They stretch when used) Its also critical you follow the torque sequence as stated.

That said I do not think improperly torqued heads would knock but can leak compression, coolant or oil. Improperly torqued timing hardware, cams, etc... maybe. A "knock" could be many things. Can you post video of it so it can be heard?

 

[F1vel66a]

I'm not leaking any fluids and compression test checked out. Add soon as I get it to knock again I will get a video. Just curious bit could a valve be sticking after driving it for a few hours? to me the fact it's not constant would rule out rods.

 

[toms89]

I'm not leaking any fluids and compression test checked out. Add soon as I get it to knock again I will get a video. Just curious bit could a valve be sticking after driving it for a few hours? to me the fact it's not constant would rule out rods.

You can get a mechanics stethoscope and pinpoint the noise location. They are relatively cheap and available at most auto parts stores or online.

 

[F1vel66a]

So looked at filter after local jiffy lube did pull change. They used fram got a Bosch on after 50 miles knock started again. deff the driver head near rear. Going to look at it more tomorrow after noon