bad lifter?

[v8s10kid]

i need some help from you guys and gals sence autozone seams to be hiring idiots now.

so yesterday i was driving home from work and i noticed a bad ticking noise. pulled over, popped the hood and listened, it sounded like the collector gasket but it was dark so i couldnt really tell 100%, i just babied it home and made plans to fix it this morning.

this morning i go out to my truck, checked the oil, ok (i changed it last week, pensoil synthetic). started it up. i got a tick when it first started but it went away after a second or two. checked it heard nothing weird. drove to work, some crap. first few miles were ok. hit the highway, still good. a few more miles later the ticking came back. pulled over and checked and it souned like it was coming from the back of the intake. coming home same thing.

i called my dad and had him meet me outside to check it but the tick stopped as i got to the stop sign 3 houses down from were i live . pulled the valve covers off and ran the motor, everything seamed ok. all the valves were opening and all the pushrods were spinning.

im stumped. i figured and bad bearing wouldnt go away and come back like that. same with an exhaust leak. i couldnt see or smell any antifreeze in the oil so i dont think its a headgasket.

so... lifter?

EDIT:
with my gear ratio i turn about 3000 rpm on the highway. and i had 50 psi oil pressure on the highway. 24 psi at idle. and temp never went over 170.

[Vegas69]

Yes, lifters can be intermittent like you describe. Your change to synthetic oil could be the problem. I'm not sold on synthetics in old technology. Especially if you have a flat tappet camshaft? Did this start right after your oil change? How many miles are on the engine? Have you ever adjusted the valves?

[David Pozzi]

Carry a 2.5 foot length of 3/8" hose with you. When it makes the noise again, put one end of the hose to your ear, and poke the other end around the engine to pinpoint the noise. You can even stick it in the oil fill hole for a listen. Don't forget to test near the fuel pump if you have a mechanical pump. There's a rubber grommet on the pump rod and if it splits the pump will knock.

Another knock I once heard on a pickup truck engine was caused by a very worn out thrust bearing, when we stopped facing downhill the knock appeared, when facing uphill it went away. The crank front counterweight was hitting the front main web on the block.
David

[v8s10kid]

i used this same exact oil last time i changed it without a problem. but yes it did start acting weird after i changed the oil. but at first it was only having the ticking on startup. it has about 135K on the truck and the previous owner said 12k more on the motor then the truck (147K). i actually adjusted the valves last night.

i got some extra 3/8 fuel line ill try that.

i figure if a lifter is bad i should replace all of them, but if im replacing all the lifters i might as well replace the cam right

[v8s10kid]

the intake lifter on the number 7 cylinder is bad. i can push down the pushrod by hand.

i like how my truck runs great up untill work desides to finally give me full time hours then BAM, broke.

[v8s10kid]

guese ill update, lifter is good, its was just some sludge causin trouble. used some gunk motor oil flush and did another oil change and she runs great, no problems. lucky me hu.