Hmm, on another thread on this forum discussing aftermarket cams, there is a link to this forum:
http://www.ls2.com/forums/showthread.php?659175-Removing-DOD-hardware-amp-fitting-a-larger-camshaft
In it, they mention an issue with '07-'08 Tahoe/Sub/Yuk engines having issues with oil pumps locking up when warm, then freeing up again when cooled down. There's a Bulletin about it:
#PIP4158: Low Oil Pressure Or Siezed Oil Pump - keywords 07 08 5.3 6.0 6.2 engine knock L76 L92 LC9 LH6 LS4 noise tick - (Jun 25, 2007)
Subject: Low Oil Pressure or Seized Oil Pump
Models: 2007-2008 Cadillac Escalade
2007-2008 Avalanche, Chevrolet Express, Silverado, Suburban, Tahoe, Trailblazer
2007-2008 GMC Savana, Sierra, Yukon
Vehicles equipped with aluminum block engines RPO codes L76 L92 LC9 LH6 LS4
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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
The customer concern may be low oil pressure, no oil pressure, or engine noise.
Recommendation/Instructions:
Complete the current diagnostic for any diagnostic trouble codes or symptoms found. If a customer concern of engine noise has been verified, and low oil pressure has been found, replace the oil pump, flush the oil cooler lines, clean the oil pan, and change the oil and filter.
It is possible for the oil pump to seize, and start to work again when the engine cools down. Evaluate all customer concerns of low oil pressure closely, and replace oil pumps as necessary.
Note: If an engine noise is noticed after replacing the