02 Tahoe with tapping above 1800 rpms

[Metaldrgn]

So I bought my 02 Tahoe this way. Noticed a tapping noise as I was driving it home above 1800 rpms. Sounds more like a lifter or something similar. I replaced all the lifters on the side that was making the noise and I still have the ticking.

Before I changed the lifters I removed the #1 intake rocker arm (the forward rocker) and the noise went away which is why I changed the lifters. Now I still have the noise so I tried disconnecting the fuel connectors from each cylinder one at a time and still have it. So I'm not sure where to go. I'm kicking myself for not checking for piston play when I had the head off because it could be a rod bearing. It really sounds like part of the valvetrain though.

Anyone have any experience with this?

 

[rockenthebowtie]

For the most part if its lower end you would get to stop tapping by canceling out the cylinder by disabling the fuel injectors it also would be more like a low hard knocking type noise... are you sure you don't have an exhaust leak look at the exhaust bolts they have a tendency of breaking off

 

[Metaldrgn]

Yes I replaced the broken exhaust bolts when the head was off. It also doesn't seem load dependent which is why I thought it was a lifter.

 

[rockenthebowtie]

Here see if this helps

#02-06-01-038: Engine Knock or Lifter Noise (Replace O-Ring) - (Dec 2, 2002)
Subject: Engine Knock or Lifter Noise (Replace O-Ring)

Models: 2001–2002 Chevrolet Camaro
2001–2003 Chevrolet Corvette
2001–2002 Pontiac Firebird
2002–2003 Cadillac Escalade, Escalade EXT
2000–2003 Chevrolet Suburban, Tahoe
2001–2003 Chevrolet Silverado
2002–2003 Chevrolet Avalanche
2000–2003 GMC Yukon, Yukon XL
2001–2003 GMC Sierra
with 4.8L, 5.3L, 5.7L or 6.0L V8 Engine (VINs V, T, Z, G, S, N, U — RPOs LR4, LM7, L59, LS1, LS6, LQ9, LQ4)
Condition
Some customers may comment on an engine tick noise. The distinguishing characteristic of this condition is that it likely will have been present since new, and is typically noticed within the first 161-322 km (100-200 mi). The noise may often be diagnosed as a collapsed lifter. Additionally, the noise may be present at cold start and appear to diminish and then return as the engine warms to operating temperature. This noise is different from other noises that may begin to occur at 3219-4828 km (2000-3000 mi).

Cause
The O-ring seal between the oil pump screen and the oil pump may be cut, causing aeration of the oil.

Correction
Inspect the O-ring seal and replace as necessary. Use the applicable part number listed below. Refer to the Engine Mechanical sub-section of the appropriate Service Manual.

Parts Information
Part Number
Description
Qty
12557752
Seal-O/Pmp (O-ring)
(F and Y Cars)
1
12563963
Seal-O/Pmp (O-ring)
(C/K Trucks)
1

 

[Metaldrgn]

Well looks like I will be pulling the pan lol. I've seen that TSB before but didn't think that would be it. Seems like a lot of miles (157k) for it to be that problem though.

 

[samotahoe]

Its kind of normal for these engines. mine makes the noise only on cold mornings at cold start but only for few seconds and goes away. When its warm in the morning now that its summer, noise doesn't happen.

 

[Metaldrgn]

I know what sound you are talking about and both the 02 tahoe and my 01 yukon make it. This is not that noise. It doesn't matter if it's warm or cold. It's always noticeable above 1800 rpms unless that one rocker arm is removed. I will make a video so you can see what I mean.

 

[rockenthebowtie]

Did you inslect the push rod to see if its plugged up

 

[Metaldrgn]

I don't recall, but I think I swapped it with the next valve over along with the rocker arm. I'm pretty sure I blew them out too before I put them back in. I'll try more when I get the time.