If you have been reading this ng, you know about my truck, its high mileage, and what I use it for. You also know that it has had a noisy lifter for about 70k miles now. I had tried several different products to pump up the hydraulic lifters, but nothing worked. I purchased some Prolong Gas Treatment for my boat (gummy carb), and it came with a "free" bottle of Prolong Oil Treatment. I figured, what the hey and put it in my truck with the next oil change. The lifter fell silent. I hauled to boat and all kinds of vacation stuff down to Wilmington and back. Still silent. It has been 2k miles since that oil change and the only time I get any noise out of the engine is if I am on a steep incline and start the motor (Yes, I also take it off-road here in Hillsborough). It is more of a knock than a lifter click and passes within 5 secs or so. That is sort concerning, but the lifter is quiet.
So it looks like Prolong Oil Treatment has some positive properties and I thought you might want to know. I won't make a dime if Prolong goes in every crankcase on the planet. The boat is running smooth as well, although the gas treatment was one of a number of cleaning agents used. I think the previous owner did not winterize it sufficiently.
Al
88 chevy ext. cab, long bed (takes a half-acre to turn around) Hillsborough, NC