oil issue?

[Dave884x4]

Posted up a while ago, thought the problem was fixed, but no, anyway. I have a 98 2 door Tahoe, 5.7L. Has a new motor, started getting a lifter noise, only on the highway, checked the oil pump, the pick up fell off, so i re-installed it, and brazed it, noise came back, pump is fine, make between 40-50 psi when warm. Replaced the lifters on the side that was making noise, noise came back, any ideas, it sounds like the lifters are not getting oiled, it is a lifter noise that I am sure of, but what might cause this, could something be restricting oil to the lifetr s and heads, if so what???

[MagicRat]

It's a rebuilt engine, right? Sometimes, rebuilders do not chase or blow-out all the oil passages, so debris might have accumulated there which is blocking oil flow.

You may have to remove the oil filter and lifters, and blow the whiz out of all the oil lines with compressed air. Also, check the lifters to make sure they are not full of debris, too.

Finally, I do seem to recall some lifters have their oil filler holes in the wrong place. The lifters are the correct size and will fit in the bores, but are not compatible with your block.

[Dave884x4]

it is a new engine, not rebuilt, and it only makes the noise at freeway speeds, above, 55-60mph. any other time it quiets down.

[j cAT]

Originally Posted by Dave884x4

it is a new engine, not rebuilt, and it only makes the noise at freeway speeds, above, 55-60mph. any other time it quiets down.

I would replace the engine oil and add 4 oz of marvel mystrey oil to engine oil....new engine needs a proper break in...

as mentioned debris in engine may be getting into the lifters the lifters must hold oil or your cam is gone .....

no fram cheap ass filter as well