It started when the thermostat stuck closed, overheated, drove it home hot. A ticking noise started, grew louder as I drove, power was down, oil pressure gauge dropped to zero. Made it home to steam/smoke coming out but no fire.
Figured out the thermostat, left it out, reinstalled the housing and hoses, topped off fluid, started, ran up to temp as oil pressure was good, no ticking noise. Checked oil level, good, not milky so I presumed I avoided warping the head. Went for a test drive, minutes later the oil pressure dropped again, ticking returned as I drove home.
Ordered and replaced oil pump, filled level, started up, everything was good, no leaks, pressure normal, no ticking. Let it idle for a while, no changes.
Went for test drive, 4-5 minutes in the pressure dropped again, ticking returned as I drove home. Pulled dipstick, oil on entire stick led me to believe it was pumping oil at some point.
Let it cool, wiped dipstick, started engine, all good, shut down when pressure gauge dropped again.
When cool enough I pulled the oil pump drive gear assembly cover, felt for play, minimal at most. Made reference marks, pulled assembly, looks to be in good condition, unlike the stories I've read as of late about the troubles with 05-06 model years.
The only two things I can think it could possibly be now is the oil pressure sending unit and / or the camshaft position sensor.
Should I just replace both of them and be done with the entire internal lubrication system? If it were the camshaft sensor wouldn't it idle rough, be hard to start or some other physical indicator? Does the pressure sending unit have any influence on the pump or does it just relay the info?
HELP IS APPRECIATED