General2.0

Hi everyone, I have a 2002 Silverado 5.3 Z71. I bought the truck with 134,000 miles on it, once I got it home, after a 15 hour drive, it started ticking, it was on and off while it was warm, and eventually it was non-stop. I let it go for a few months with it ticking whenever the engine was running. Finally, this summer, I put a new cam, lifters, pushrods, oil pump, water pump, pulleys, belts, thermostat, and all new hoses. I had the heads rebuilt, new matching valve springs, new gaskets, new oil pump, timing chain, timing chain cover gasket, and some other little things. I installed a 216/220 .550/.550 112Lsa Texas Speed cam, 7.40" hardened pushrods (says 7.40" on them, so I didn't bother to check it with a gauge). I believe they are ls7 lifters, not sure since they came with the cam. Got it tuned as well. Now, the problem I'm having is that I hear the lifters making noise at start up, I can't tell if it's one or more, but I hear it at start up only. And only once have I heard it while I was driving, and it was bad. The only thing I didn't replace were the rocker arms cause I was told they looked fine.. However, I replaced 2 arms a few weeks after the rebuild and it still ticks. I replaced the new ones with the 2 worst ones. Could it be the rocker arms just warn out, causing some play? My other question is, I replaced the oil pump, and I read a bunch about the oil pump o-rings going bad, when I put the new oil pump on, I forgot to check the o ring, I didn't see one on the pick up tube when I took the old pump off, and the pick up tube had a flange about 1 inch from the end, I thought that was the seal, I didn't see an o ring with the new oil pump, so I just put the new oil pump on. My oil pressure seems perfectly normal, with 5w30, like it says on the oil cap, it runs perfectly normal. No, I haven't hooked it up to a mechanical oil pressure gauge. But it did notify my of low oil pressure one time, before it was tuned, and I watched the oil pressure increase as I gave it some throttle. So I doubt it's the gauge. I figure, if it did need an o ring, and doesn't have one, why would the ticking go away? And I might have put one on, I just don't remember. And there's hardly an air bubbles on the dip stick when the engine is at operating temp, so the oil doesn't seem to be mixed with air that would leak past the seal. I changed the oil a few hundred miles after the rebuild, and I used the correct oil filter. I did almost everything by the book. I torqued everything down too, I checked the rocker bolts as well, made sure they were still at 22ft/lbs. I understand that lifters can bleed out, but they are brand new, I feel like that shouldn't happen. So my questions: could it be the o ring, if it needs one? Or could it be the original rocker arms? I am open to suggestions, I would rather not take the heads off again though.

kinglt-1

iTrader: (26)

The oil pump O ring should have been replaced. Second thing is you should measure for correct push rod length.

bbond105

How do you know if the pushrods are the correct length? How much did you preload the lifters? Any time you make changes to the valve train, (cam, heads, valve job, rockers), the pushrod length needs to be checked.

Docrocket1967

iTrader: (1)

If you're worried about the o-ring this was my experience with it.... On cold start oil, cold oil, pressure was good and no sounds were made at all until it warmed up. Once it warmed up and the engine got about 150 degrees it began making a noise like a small knock then oil pressure woulf drop the warmer it got until it hit about 20 psi and thats when i shut it off. Oring was the whole issue and when i replaced it the noise never came back and oil pressure has been 40-60psi ever since.

Good luck hope its a simple fix

gagliano7

So you didn't replace the o-ring with a new one and aren't sure if there is one on there? I would say that is your problem.

psychosid30

iTrader: (7)

As every one here has said, you need to pull the pan and check the o-ring on the pick-up tube.

General2.0

I have thoroughly read all of your replys and have come to the conclusion that i am going to install a new oil pump o ring and probably the inlet tube and screen. So what do i need to know and how should i go about this? I am hoping everything can be accessed through the oil pan, is that possible? What do you guys recommend be my procedure and new parts list? All i know is i need a new oil pan gasket, o ring (is there a specific o ring i need? if so, where can i find the right replacement), oil pickup tube and screen, new oil and oil filter,...? also, any recommendations on type of oil? I usually run Valvoline High Mileage synthetic blend 5w-30. The guy who owned the truck before me used an oil that left a ton of sludge in there, should i clean off the crank or any parts in there? if so, what type of cleaner? i dont want to harm any bearings or parts. Sorry for all these questions, its my first time pulling the pan off and i want to do everything once and do it correctly. So any tips or tricks are greatly appreciated.

Thank you all for the responses!

kinglt-1

iTrader: (26)

the inlet tube and screen should be fine...all you need to do is replace the o ring around the pick up tube and it would not hurt to change the cam retainer plate gasket while you are there. Then properly measure push rod length instead of just "winging" it.