Yea, gotta be careful with some of that crap.....some of it is paint thinner with a fancy name in a new bottle. If you wanna flush your motor, drain out some and pour in some diesel and run it for a few minutes at idle. On a high milage motor, even THAT is dangerous, cause it will beak all that sludge loose. When doing that, always be prepared to pull the pan.
I've flushed them like that, ran them for 10 or 15 minutes idling, watching the pressure guage I had screwed into the sender hole. I'd shut her down once the pressure starts fluctuating....that means the screen is starting to stop up. Pulled the pan, cleaned everything really good, drop in a good Hi-Vol. pump and new pickup....button her up....change the filter....new Heavier oil than was used....and fire her up. Watch the pressure guage carefully....after she runs for 15 minutes.....your gonna want to change your oil and filter agian. That should've caught any crap floating around in the system.
Now, put in the same wt. oil and a new filter....she should be good.
When you remove all that sludge, your oil pressure is gonna drop noticeably. That varnish and sludge on the crank throws between the rods and on the mains keeps the pressure from bleeding off when the bearings get really sloppy. Ever pull a set of lifters outta their bores when the motor has about 200,000 miles on it and they didn't change their oil correctly??? Theres a ring of varnish around the bottom keeping the lifter from coming out....that helps keep the pressure up.
With the mess gone, and the clearence bleeding off pressure quickly, you'd need to go with a thicker oil to float the bearing and keep your pressure up. The new pump will help that too.
Hope all this helps.....they do have the additives that unstick rings and lifters.....and Bradahl makes such a goo....it works and is good. Just be careful anout adding any motor flushes....those can be deadly to your motor if your not careful and don't know how to use them.....
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