Sustained ticking 70+mph

[Ken Rolls]

So my 02 suburban with 356,000 miles runs very well. It's been maintained and serviced. New rear main/pan gasket/valve cover gaskets. Regular oil changes etc. Around town it's very quiet and for what she is it pulls strong. 7.7 0-60 with those miles is impressive. I'm trying to figure out the lifter/valve train noise at highway speeds. I can't tell if perhaps a lifter isn't pumping fully or maybe a pushrod is worn to the point of losing contact with the lifter and causing noise. I have to pull over and shut it off and wait a few minutes. Sometimes it works but not always. I've read the oil pump o-ring can cause issues similar to that. When I goose it the oil pressure spikes off the board and goes goofy for a minute. Sending unit is new. Oil is 5w-30 full synthetic havoline with an extra qt of Lucas. Nothing helps.

 

[Mudsport96]

Does the ticking stay the same in 3rd at the same speed?
It is common for these to wear flat spots on the pushrods and mating rockers. Since they dont rotate like the old flat tappet style did.

 

[Ken Rolls]

Does the ticking stay the same in 3rd at the same speed?
It is common for these to wear flat spots on the pushrods and mating rockers. Since they dont rotate like the old flat tappet style did.

Have never tried to shift down. I was leaning o ring in the pickup tube but the psi is steady 40-45 psi

 

[rockola1971]

Have never tried to shift down. I was leaning o ring in the pickup tube but the psi is steady 40-45 psi

If Oring was leaking the oil pressure would be jumping around substantially. Pop the valve covers off and inspect for damage, abnormal wear and excessive rocker clearance.