Re: Engine Sludging with Premium Synthetic Engine motor oil.
I had a 4 cyl 16 valve. 5 speed Camry Wagon 23,000 miles diagnosed with a engine knock. On its third oil change.
Toyota Service stated the reason for the problem was the oil being used. A 100% Premium Synthetic.
I had complete oil service records, and with the Synthetic Oil Companies support, after months of written and verbal discussions.
Toyota agreed to do the repair with their top mechanic on the repair.
With a signed inclusion that I may have to foot the bill if it was a oil related problem.
The mechanics repair found faulty valve train components,the parts were replaced at Toyota's cost. The Dealers Top Mechanics repair sub notes were "this was the cleanest block he had worked on", "no oil related concerns"
The mechanic pulled me on the side at the time of vehicle pick up asking me what was the brand of oil I used, the service writer / service management had not informed him.
To all concerned, which ever side of the fence your on, be a consumer with armed facts, and service documentation. Very few consumers with out of warranty engines receive due compensation and too many consumers within warranty fall into the voided category.