5.3 ticking/knocking sound, cold start...

[Barry]

Hi Folks,
Have a 2001 Tahoe Z71, with only 87K on it. On a trip up to Mt. Rainier the motor started making a "ticking" sound, and seemed to be there even after warm-up. It would go away, as well, here & there. But it easily made the 7 hour round-trip to the mountain & back. Now the noise is there on a cold start & seems to go away after 6-8 minutes. I'm on Whidbey Island (Puget Sound) & the local mechanics are nice, but not 5.3 experts. It's a ferry ride to the mainland dealership, but I feel they know the 5.3 in & out. The island mechanics checked a bulletin & are sure the o-ring in the oil pickup is shot & needs 5 hours to replace at $600+. I'm not losing any oil pressure at startup & it's at least at 45 going down the road, so I'm not sure. I thought it could be the exhaust manifold gaskets that could be shot & are sealing back up once the block & manifold expand a little on warm-up. The issue is that I don't know what the sound of an exhaust leak, or lifter noise, etc. is supposed to sound like. I know the 5.3 has had issues with manifold bolts & so on. Any opinion would be greatly appreciated. Thanks.

 

[redhoe1]

Sounds like the 5.3 piston slap. My 2002 had it when we bought it when it had around 160k miles on it. The sound has gotten a little worse but still goes away when warmed up, have 270 k miles on it now. Just part have owning a 5.3.

 

[Barry]

5.3 ticking sound..

Thanks for the feedback. It's weird, but now the noise has stopped ... even on startup. I feel bad for the shop that was convinced it was an O-ring in the oil pickup that was shot, and it still could be that. But I didn't want to just drop $600 for the hell of it. Really need to get it to the dealership in the mainland for a look.
Barry