1996 1.6 16v engine noise

[Agk007]

one test is drop all belts, (hot) and run for 1min, only see if noise ends belts off, (alt,AC.water pump..PS belt) only
short time. as it will overheat fast longer.
or warm it up until noise starts and drop belt.
other wise if inside engine is the noise, make sure the rocker springs are not missing. 8 of them below.


and lash set right. TDC firing each piston.




make sure all things attached to engine not loose. even that huge air pip up top has 2 read exh,man. bolts, and more. not loose.
put pressure with hands or short 2x4 board, on to things, see if sound changes
flex the exhaust header to CAT with a board, to make sure it is not bad or the bad header flange donut not bad. and loose, (horrible pounding sound with tha bad, sounded like bad rod bearings. on mine, new engine and scared me...
keep open mind on externals. use pressure or yank thing to find any thing loose.
good luck you , on you project !!!

So I warmed it up and dropped all belts, the noise was still there. I even removed the camshaft and inspected the cam bearings, lobes, and rocker surfaces and all seems fine outside of some wear due to mileage. I went ahead and had the cam polished as well while it was out and even had the rocker surfaces re-arched by a machine shop I noticed when I open the oil fill while it’s running you can hear it much more pronounced so it seems to be coming from inside the engine. It sounds at the speed of the cam and not the crank. If I pull injectors one at a time the noise doesn’t change. I even pulled the pan to check rod bearings and all that. Everything seems fine. It still seems to be coming from the head. I checked the oil and cut open the filter with no bearing debris present, looked fine to me. The head was re decked and all the valve guides were replaced because they were worn when I rebuilt this engine. I’m running out of ideas outside of maybe there were some mismatched valvetrain components (since I bought this head used).

Attached is a link to the sound so you can hear it.
https://youtu.be/jMBIFMJD0ps