TSB 01-035- (Oct. 17, 2002) applies to 2002 Avalanche, '01-'02 Silverado, Express, Suburban, '01-'02 GMC Sierra, Savana, Yukon XL and '01-'02 Chevy/GMC C6-7 Conventional Cab Medium Duty and B7 School Bus Models with the 8.1 litre engine (VIN G, E--RPO L18)
"Some customers may comment about higher than expected oil consumption. Because this type of engine is used under various load conditions, the dealer should verify that the vehicle is using more than 0.946L (1 qt.) of oil for every 379L (100 gallons) of fuel used." As stated earlier in a post, oil vapor was being pulled into the combustion chamber through the intake manifold. The correction is to replace all the intake manifold bolts one at a time in sequence to keep the manifold from shifting. Each manifold bolt should be tightened to 44 lb. inches then again in the sequence specified to 71 lb. inches then to 106 lb. inches. The intake manifold bolt part number is 12561518 and you will need 10 of them.
'01 2500hd ext. cab, 8.1 litre gas, 5 sp. Allison auto
3.73 rear end
Mag-Hytec rear diff cover
Amsoil Dual by-pass oil filtration system
Amsoil synthetics all around
265 watt AM Solar, Inc. system