GENIUSLOERTS

hey everyone,

I just got a 1990 f150 that I pulled out of the in-laws back yard. it has the 4.9 and auto trans, 2wd. I was told it was making some engine noise and had gotten parked 6 years ago because the ignition linkage broke before he could get it to a shop. Well i have towed it home and replaced the fuel pumps, cleaned the tanks out, new filter etc. to get the fuel working properly. I got the truck started after fixing a injector harness that some critter had eaten. truck was running great until all of the sudden oil pressure was gone and a lifter started to complain. I turned the truck off let it sit for a while started it back up and i had oil pressure again and engine was quiet. after a while, the oil pressure was gone again and the lifter started to complain.

so needless to say there is a problem. What is is doing now are the symptoms that my father in-law had with it before the ignition broke. I have done some searching online and in various forums to see if anyone has had the same problem. nothing seems to be like this one.

so here is some info to help, filter and oil are new(was golden clear before). father in-law changed the oil every 2000 miles, and still encountered this problem. I changed the valve cover gasket while i had the intake off to fix the injector harness. I found a lot of carbon-tar build up crap around the valve-train that i scraped off while having the shop vac sucking it up.

my thoughts thus far is that there is some sludge in the pickup screen that is restricting oil flow after running for a while.

any other ideas?

joe mcmillan

I agree with your analyses. Those holes plug with the carbon over the years leaving very little capacity as more and more plug. The only way to clean them is to drop the pan and clean the pickup screen completely. Motor flushing and additives are both a waste of time and material.

GENIUSLOERTS

yeah, I'm anti anti-sludge additives. my brother had a car that he took to a place to have the oil changed and they ran some de sludge stuff in it and not a week later the engine lost oil pressure, we pulled the pan off cleaned the screen and put it back together and a week later the same deal. it eventually lead to the death of that engine.

GENIUSLOERTS

Well, I have had the issue resolved for a couple weeks now. I dropped the oil pan and found some awesome stuff. see the pictures below. I was talking to my father in-law about this and he was pretty upset because before he parked it(because of the oil pressure problem) he had had it in at a shop to have a main bearing replaced, they were in the bottom end and put it back together in a less than par manner. you can see the pickup screen and how they bent it to try and clean it out and or allow more oil flow. why they just didn't replace the pickup tube for $14 is beyond me. I flushed the engine with diesel until it came out clean and put it back together. So it now has a new pickup tube/screen and oil pump and is running great. I just need to get some new tires because the old ones have some flat spots on them for sitting for 6 years and I don't like all the shaking.