Lifter tap 1999 GM 6.0L

[hisilver]

The engine taps really loud wether hot or cold. Its getting pretty annoying. Has about 135K miles, used and abused. Forgetting a valve train adjustment, would a 40wt make it worse or better? Would the thicker oil quiet this or not flow as much and make it louder? Currently using Pennzoil Platinum 5w30.

 

[daman]

Lifter or piston slap common on these mills they run for ever still, sell it or live with it oil seems to have little to no effect on it,try a different brand but PP is a good oil.

 

[StevieC]

Gotta fix the problem right, oil won't fix it if they are manual adjusted lifters/valves.

 

[daman]

There hydraulic so no adjustment needed,could have a bad lifter that gummed up from neglected OC and it's not pumping up right.

 

[StevieC]

If they are hydraulic based with no adjustment then it could be an oil flow problem because the oil pump is worn or piston slap like another member suggested.

I don't have experience with this specific engine so I can't say if it is common and what the problem may be but I can say that using an oil with a flushing agent might fix the problem.

Try using a 40wt oil like Pennzoil with a quart of MMO in it and a quality oil filter and see if it fixes the problem. If not have a mechanic diagnose it.

 

[daman]

Usually oil pressure on these GM engines or any engine aren't a problem so i vote bad lifter/s or PS.

 

[oggb]

-Add a quart of ATF to the oil, idle it for 5-10 minutes, see what happens. If it sounds like it's getting better but it's not completely gone, idle a little longer. After you're done dump the oil/atf mix and change the oil and filter.

-Add a quart of diesel to the oil, idle for 5-10 minutes, see above.

-Add seafoam to the oil, run it for a short period of time and don't run the engine hard while the seafoam is in there.

The above do actually work on sticky/noisy lifters.

 

[kc8adu]

sure its a lifter?
i have heard some really nasty piston slap in these.
lifter click is at half crank speed.

 

[MrCritical]

Could be carbon build up.

 

[StevieC]

Put a Ford emblem on the front, then you will have different problems...

J/K Nobody flame me now!

 

[bretfraz]

10 to 1 it's piston slap. Common on those Vortec engines. Took GM until 2004 to fix the problem. although my 5.3L does it a little bit.

Oil has little effect on the condition. You can try a higher vis 30W, something like GC, to see if the noise diminishes. Pennzoil Platinum is another excellent choice for any modular Vortec engine. Beyond that, don't worry about it. It is what it is.

 

[hisilver]

I didnt think it was piston slap because it never made a noise until a few months ago. Also it taps hot and cold ALWAYS. If it was PS wouldnt the heat expand the pistons and such to slowly reduce the noise as you drive? I think im game for using maybe T6 5w40 and a quart of MMO next change, which will be soon.

Also the oil pressure is at 40 warm idle and goes up depending on how hard im hammering on it, consistent with all the gm trucks ive owned.

 

[daman]

Try a good run of MMO, 1 qt to a OC.

 

[SteveSRT8]

we've killed dozens of these motors in 3500 Savanas. Piston slap varies wildly from one to another, and is the most common.

If it taps at half crank speed for a few seconds and shuts up, it's a lifter. It is extremely unlikely that any oil or cleaner combo will affect it. And it will still run forever. I've got one with over 400k miles on it working daily!

And if you've got 40 psi at a hot idle you are WAY above spec. Don't go to thicker oil unless it burns a lot.

 

[jazeo]

Originally Posted By: SteveSRT8

And if you've got 40 psi at a hot idle you are WAY above spec. Don't go to thicker oil unless it burns a lot.


+1 I was about to say the same thing when I noticed your comment. He did say warm but I'm guessing he did mean up to normal operating temp and 40 is way high. Maybe he's using a factory temp gauge that isn't accurate. Usually 40-60 @2000 rpm is normal and I'll guess about 18-20 @idle. At any rate if it is that high I would not use a thicker oil...

 

[hisilver]

With the proper six quarts the operating temp oil pressure at idle is just below the 12 oclock position, which i think says 40, i will have to check that number. My 5.3 takes six qts also and the oil pressure guage acts identical.

 

[daman]

Originally Posted By: hisilver
With the proper six quarts the operating temp oil pressure at idle is just below the 12 oclock position, which i think says 40, i will have to check that number. My 5.3 takes six qts also and the oil pressure guage acts identical.

Your pressures are spot on nothing wrong with it thats where they run on these trucks with the factory 5w30.

 

[jazeo]

Originally Posted By: daman
Originally Posted By: hisilver
With the proper six quarts the operating temp oil pressure at idle is just below the 12 oclock position, which i think says 40, i will have to check that number. My 5.3 takes six qts also and the oil pressure guage acts identical.

Your pressures are spot on nothing wrong with it thats where they run on these trucks with the factory 5w30.


Are you saying the gauge is accurate and 40psi @ idle is spot on for those trucks with 5w30 ???

 

[daman]

He said just BELOW 40 to the right of the 40 mark.

depending on oil temps yes around there.

 

[jazeo]

Read it again