Link Here please.
https://www.fordforum.com/m_32777/tm.htm

 

Engine oil flushes are not recommended by any vehicle manufacturer, as far as I know or have heard. GM even put out a TSB about engine flushes, there are chemicals in the flush that are not compatible with engine parts. I worked at a Ford dealer for 20 years, and I know Ford does not recommend engine oil flushes. Regular oil changes should keep the inside of the engine clean enough, what with the detergents and additives in quality oils.

Personally I do not like Pennzoil, seen too many sludged engines that were using those products.

 

they do more harm than good.