Engine "Flushing"

As my trusty 'ol 5.0 has been hurting in the oil pressure department (idling at around 20 psi,, dropping further under load) I just got a new high volume-high pressure oil pump from Jegs.

Before I install it, I'd like to flush all the oil passages in the engine to remove any gunk that may have accumulated it the engines 60k mile life.

I have had a couple old-timer mechanics tell me a good way it to put about a quart of diesel in the crankcase with the oil, fire the engine up but dont drive it and get it "good n hot", it was recommended to put a piece of cardboard in front of the radiator to stop airflow, as it needs to get over 200 degrees, then let it run at idle for about 10 to 15 minutes, then drain and preform a normal oil change. (or in my case pull & clean the pan & pickup tube and replace the pump)


Any other thoughts or methods?

 

i have heard that, transmission fluid, and that sea foam stuff is supposed to be good for flushing too. i know it works good on the intake.

 

I have used Sea Foam with good results

 

I seem to remember Berryman B-12 also does this. I think that there are instructions on the can.

 

Just remember to change the oil and plugs after using Sea Foam

 

You run detergent oil? If so, I doubt you're going to have much effect on the cleanliness of the engine by adding extra stuff. If this is an engine that has suffered infrequent oil changes, I'd suggest you simply run a few quick oil/filter changes to remove any soluble gunk. If you really feel the need to do something, oils spec'd for diesels have a lot of detergent - you could run a couple of changes of that. ATF is effective because it contains a lot of detergent... but modern oils have detergent too. Add ATF and you won't know what they viscosity of your oil is, but you'll have more detergent. Detergent works.

No way would I try the diesel fuel method - this sounds to me like something left over from the days of non-detergent oil ...

Note that I am just guessing at what will be effective... but my opinion is that any approach other than just changing the oil/filter has to be classified as "snake oil" until proven otherwise.

 

My dad used to swear by "Rislone"

I have also used it with good luck in old gunked up engines.

 

I vote for Rislone too. Used in my cars and cj5.

 

I agree with the high detergent oil idea. My friend bought an old Cherokee with 4.0 that was all sludged up. He pulled the valve cover and physically cleaned out what sludge from the valve area that he could then filled the engine with Chevron Delo 400 and ran it. He did his first oil and filter change at 200 miles and continued to change filters every 200-250 miles for 1000 miles. After about 1500 miles, there was a noticeable difference and the engine really quieted down, ran smoother and the gas mileage picked up noticeably.

 

killed a small block chevy by flushing it sent all that crunchy stuff through the crank with rislone lasted two 50 mile trips

 

As to Tim's comments, Im just wanting to clean things up a bit before installing the new oil pump. This engine had 60k miles on it and it was well cared for prior to the swap, but it also sat for over 14 months prior to and during the swap. I guess I really don't need to flush it out, but I also just hate installing new parts in an old dirty motor.

Maybe step 1 will be to drop the pan and check things out, then decide the best course of action.

 

High Detergent oil will also clean out the sluge thats preventing all your seals from leaking.... Just so you know a rear main may be in your future....