08 Silverado 1500 CC

[Flashcb]

How common is it for the oil pump to have a problem? I have this sqeak/tap on my truck. The tensioner and the belts are all ok. Pulled all the belts off and still had the squeak. it seems to run with the RPM of the engine.
Next question since the oil pump is under the timing chain cover, anybody can tell me how long the book says it should take to change it?

 

[alexrex20]

I'm assuming the 5.3 V8? The early engines did have issues with oil pump failures, but you do see it every now and then on the '07 and even '08 trucks. I don't know book rate on it, but it's a fairly simple job: drop oil pan, remove water pump and front cover. Then remove (and replace) oil pump. I'd say any decent weekend mechanic could have it done in 2-3hrs.

It's hard to diagnose noises over the Internet, but you should also check anything that's connected to that serpentine belt - water pump, alternator, power steering pump, AC compressor, even the balancer. Remove the belt and spin everything by hand, or grab the pulley and see if it has any play. They should have zero play and spin nice and smooth (and tight). My bets are on the alternator.

Edit: Most of the oil pump issues I've seen on the 4.8 and 5.3 were sheared shafts or grinded gears. It would be a complete failure and zero oil pressure. I doubt it's your oil pump.

 

[alexrex20]

Shit, I just reread your post and noticed that you said it still squeaks with all the belts off.

The tap could be lifter tap. Try some Seafoam in the oil and vacuum line. Better yet, drain the oil, refill with ATF (yes, automatic transmission fluid), drive it for about 100mi, then do a full oil change. ATF has excellent detergents and will really clean up any blocked passages - like in a collapsed lifter.

Can you describe the squeak in more detail?

 

[Flashcb]

This is the sound, although it usually has more of a squeak to it. [video]www.youtube.com/watch?v=mceDi6hrXnM[/video] it is the 5.3 and the noise is coming off the bottom of the engine. The reason I wondered about the oil pump is that at idle the gauge seems to go down sometimes. i.e. when you start it it goes up to 40 or so then once it warms up it will go down to about 20 or so, then as you rev up it goes back to 40-50

 

[alexrex20]

This is the sound, although it usually has more of a squeak to it. [video]www.youtube.com/watch?v=mceDi6hrXnM[/video] it is the 5.3 and the noise is coming off the bottom of the engine.

It made this same noise even with both belts removed? If so, I would say it's an exhaust leak.

The reason I wondered about the oil pump is that at idle the gauge seems to go down sometimes. i.e. when you start it it goes up to 40 or so then once it warms up it will go down to about 20 or so, then as you rev up it goes back to 40-50

That is entirely normal. As you load/rev the engine, oil pressure goes up. Those numbers are exactly where they should be.

 

[zembonez]

Later 5.3 almost never have oil pump issues. It is however VERY common for the AFM lifter garbage to have problems. Oil consumption, noise, etc. What the OP describes is perfectly normal oil pump operation.

 

[Paul5388]

After listening to the noise, it sounds more like lifter noise than anything else. I can't feature anything in the lower end making that sort of noise. Of course, the latest thing I've had that resembles that engine was a 1987 5.7 in a 3/4 ton.

 

[1slow01Z71]

Take a long extension and put it on the valve cover with your ear up to the other end. Should make it easier to hear if its the lifters. Ive also had needle bearings in the rocker arms crap out that gave that noise.

 

[mitchntx]

Is it a standard trans truck?

Reason I ask is that I've seen plenty of LSx Trans Ams, Camaros and Vettes bend push rods after missing the 3-4 shift and mechanically over reving the engine.

 

[Das Jared]

Is it a standard trans truck?

Reason I ask is that I've seen plenty of LSx Trans Ams, Camaros and Vettes bend push rods after missing the 3-4 shift and mechanically over reving the engine.

No

sent from my dishwasher

 

[Paul5388]

The make shift stethoscope to listen to the engine is a good idea. A long handled screwdriver can also be used.

 

[mitchntx]

No

As in its an automatic trans or as if its not possible?

If the latter, if at the top of 3rd gear, miss the 4th gear gate and go to 2nd instead and then let out the clutch, it'll mechanically over rev the motor.
Unfortunately ... I've been there and done that.

It causes a lot of strange noises ...

Fortunately it's not an expensive fix for an LSx design ...

 

[Flashcb]

Is it a standard trans truck?

Reason I ask is that I've seen plenty of LSx Trans Ams, Camaros and Vettes bend push rods after missing the 3-4 shift and mechanically over reving the engine.

nope it is an automatic. Still Haven't had time to chase it down

 

[mroper]

They sell engine stethoscopes at autopart stores as well.