Two problems related to oil pump have been reported for the 2000 Chevrolet Silverado. The most recently reported issues are listed below.
Noticed engine knock on cold start-ups as soon as vehicle was purchased. Purchased vehicle in oct. 2000, with 39,000 mi. (2nd owner) at approx. 85,000 mi. , noticed engine making a rattling noise as transmission up-shifted in 1st & 2nd gears after cold engine start-up knock went away. Took vehicle to dealer and was told that cold start-up knock was normal, but rattling wasn't. Dealer gave me service bulletin #01-06-01-028 which states that cold start-up knock may be caused by an interaction between carbon on piston, piston motion, and cylinder wall. Vehicle presently has 89,000 mi. On it and approximately 80% of said mi. Are highway mi. , so, carbon in my estimation, doesn't come into play! as far as the rattling sound goes, dealer found the hardness breaking down on camshaft lobes #1 and #4 (from front of engine). Dealer replaced camshaft, 2 lifters, and oil pump. Upon completion of said repairs, low and behold, I didn't notice any more cold engine start-up knock! you figure it out, but, my guess is, is that gm has a problem with it's camshafts again. (1970's and early 80's).
Engine check light went on day after purchase. Saturday. Returned to dealer on Monday for checkup. Dealer said they couldn't reproduce the problem. Check engine light went on 08/10/2000. Returned to dealer. This time they checked the national computer and found that the knock sensors were overtorqued at the factory and replaced them. Why didn't they check the national computer when they had the truck the first time? started truck up in am 11/13-/2000 oil light came on. Checked oil, was full. Started truck up again, thought maybe guage was incorrect. Still no oil pressure. They towed truck in and replaced oil pump. The mileage was only 4513. I wanted engine replace, but they said there was no damage . Gas pedal sticking at 23550 miles. Returned truck to dealer. They installed new throttle body. Also oil filler tube was not installed correctly. Oil was leaking from tube. They fixed this also. At 26581 miles engine started to have valve noise on cold startup. Returned to dealer. They said nothing was wrong. On 12/05/2001 returned truck due to tapping noise. This time they said it was due to castrol oil filter. They changed oil and put on pf59 filter. Thought problem was fixed. Engine still has lift noise on cold startup. Also complained of transmission double shifting. Dealer can't find anything wrong. This truck has been in the shop so many times they should extend the warranty to 10 years, but I know they are afraid to do that.