Posting this for a friend. He has a 2007 Silverado with the 5.3 and about 85K miles on it. He had an issue a few months ago where the low oil level message popped up on his dash. He stopped the truck and checked the oil. The dipstick showed he only had 2 quarts in the oil pan. He added to the full line and then took the truck to the dealership to get it looked at. They said he had too much oil and drained out about 4 quarts. The problem happened again yesterday and he has no idea what is causing it. The oil will just reappear at a random time after the message pops up. Are there any know issues with the oil drain system on the 5.3 that could be causing this? Any help would be much appreciated.