My friend has a fleet of Savana vans, which religiously go to the J team every 3500 miles. Last year one if them had the oil light flickering and the valve train clacking. I dropped the pan and there was an inch of sludge on the bottom, and the pick-up screen was plugged up. It has 189,000 miles. I don’t need oil change receipts to tell if an engine has been maintained.
With a 6 inch high stack of oil receipts from the J team, there’s no way that engine should have been sludged. One could speculate why, but the bottom line is it shouldn‘t have happened.
He’s now using the dealer and supplying his own oil.