Posted by Peter on July 12, 01 at 13:27:08:
I realize that TSB is about a year old but with all the recent discussion about engine noises, maybe it will help someone.
(Copied out of the current Popular Mechanics - Aug '01 I think)
General Motors: 1999-2000 Cadillac Escalade, 1995-2000 Chevrolet/GMC/Oldsmobile S/T truck, 1996-2000 Chevrolet/GMC C/K Truck with 4.3L, 5.0L, 5.7L or 7.4L engine (VIN W, X, M, R, J)
Subject: Hard-starting, slow cranking or unusual grinding noises, backfire or kickback may all be caused by a faulty crank position sensor. These symptoms will probably be accompanied by DTC P0338, but the SES light will not be turned on. The problem is caused by a faulty CKP sensor, which allows up to 50 extra degrees of timing advance during starting. This can cause serious damage to the starter or flywheel or even crack the engine block at the starter mounting boss. If the DTC is stored, a new CKP must be installed, P/N 10456607 to avoid recurring problems. Bulletin 00-06-04-014