Re: Engine Knock...
They better honour a new warranty on the engine, 3/60K kms. Rebuilt or not.
I know on older engines to cure a knock you just up the octane a bit, or use a thicker/thinner oil depending on application.
The problem these days is that manufacturers are running SUPER light oils in engines to try to eke out every last possible 0.001% worth of fuel economy to help their CAFE rating. Long term, mostly after the warranty, running 0W20 oil isn't always the best course. Running the standard 5W30 synthetic is the way to go. Dealers also profit more from running lighter oils, as they charge more for it unless the dealer includes a maintenance paid package with the vehicle for a certain length of time.
You can always phone Ford directly about inquiring about a proper, er full, warranty on the rebuilt engine if the dealer gives you any grief in the matter. It might take a couple days to get a response, so you might even want to call now so you have their attention and they can contact the dealer about the change.
'00 Durango R/T 360ci 290hp (modded); 138,500m
'06 Pontiac G6 GT 3.5L 220hp; 44,000m
'12 Chrysler 200 Limited 3.6L 283hp; 13,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!