Friend's 1987 Ford Aerostar 3.0L
Peak 10W40 and Purolator 30001 filter (FL1A, takes a FL400S but there is a reason for the larger filter and different weight than OE 5W30)
We flushed the engine with gunk HM oil flush, and despite having jack stands, air tools, etc. it took us about 10 hours to do it, mostly due to the cramped conditions underneath, and not backing the trans off the engine. we did put it all back together properly in the end.
Now here is why we did that, the oil pressure gauge was erratic, even after he replaced the sender unit. So his idea was to dump gunk high milage engine flush into it, run it through for 5 minutes, let it sit for 20-30 minutes, and then remove the pan, clean out the pickup screen, replace the gasket, put it back together.
I did not fully approve of this, but i figured that without me he would mess it up more than i care to imangine.
After using the flush the internals of the engine looked pretty clean, at least what i could see on the underside through the oil pan that never came out fully, we used rags to clean the pan out from the flush.
Will i ever do this on a ford aerostar again...no way without 50 bucks in restitution. I did hte ugy a favor this time, but he is going to help me replace the valve cover gaskets on the sable, and flush the radiator.