ok here goes. My valve cover on my 83 f100 w/ 79k was leaking and I finally decided to replace it. The truck is basically a trash truck and only gets 1k put on it a year. Needless to say the rockers were covered, and I mean covered w/ crap. I scraped and cleaned them and flushed from the top of the engine to the bottom w/ kerosene. I continued the cleaning by replacing 1 qt of oil w/ atf. The truck ran excellent with great oil pressure but I must have cleaned too well. The pressure has dropped off considerably and I am pretty sure I have a clogged oil pickup. Here my question-what would be the harm of filling the crank w/ kerosene or a cobination of degreaser (I'm open for suggestions) and letting it sit for a wk. drain it and do it again? Does anyone out there think that might work?

 

Kerosene is not a good lubricant. If you want to trash the engine, by all means do it. If not, change the oil and filter, run the engine a little while, and then change it again. For safety's sake, I'd think about changing it 3 times. You've obviously loosened up a lot of trash, so you may have to drop the oil pan to clean it out. Either way, I'd definitely change the oil and filter... fast!

 

Washing the main, rod, and cam bearing shells with harsh solvents, especially during operation, ain't a good idea. You can strip some of the babbitt layer right off. If you drive 'er around while that stuff is in there thinning out the oil, you might be looking at the second layer of your bearing shells when you go to freshen up the bottom end. A wise, old mechanic told me, way back, that sometimes flushing the motor does more harm than good, and you're best off leaving some of that buildup right where it is until you reman the motor. Certainly there is some wisdom to that, as you don't exactly want the grit embedding itself into your bearings especially with some solvent thrown into the picture after it pops the filter bypass.

I'd do just wat da wiseguy sez...or Gino might get a little upset, and when he hasta interrupt his spaghetti dinner in order's to get upset...bada bing!

I've heard of using #2 home heating oil or diesel to flush, but kerosene may be a little too harsh. I use a shop-vac on the top-end garbage, and clean and dry the removeables away from the engine, then flush using a quart of Mystery Oil at an idle, then change the oil+filter before going anywhere, letting it drain for awhile.

 

Yeah, motor flush on a really dirty engine is "instant rod knock" because the trash comes loose, plugs up the filter and then the bypass valve opens and the trash goes straight to the bearings.

The best idea is frequent oil changes, maybe 500 - 1000 miles at the most. The detergent will clean up the motor but slowly enough that it won't destroy it.