1986F150Six Posted October 5, 2017 Share Posted October 5, 2017 On 9/14/17, my 1986 F150 was being called upon to drive ~570 miles to Skiatook, OK, for the 2017 OK GTG. It has made this trip 3 times before. This truck is powered by the 4.9L engine [Duraspark conversion]. The engine has 205K miles and has always run great. My beautiful wife was with me and as we approached Memphis, TN [~100 miles into the trip], the factory oil pressure gauge began to drop. I quickly looked at the fuel and temperature gauges to see if the ICVR was acting up. The temperature gauge was a little lower than normal, but the fuel gauge was about where I would expect it to be. I continued and began to hear tapping. I pulled to the side of the road and listened. The sound was like that of a sticking lifter. I opened the oil fill, with engine idling, and could see oil flowing and the ticking sound stopped. I tried again and as I got up to highway speed [65 mph], the sound returned and worsened. I did a gut check and a small voice told me to head back home. You have to realize that there are parts of Memphis where one does not want to break down with your loving wife of 34 years! The further I drove [longest 100 miles of my life], the worse it sounded. The oil pressure gauge was steady with the "N" of NORMAL. I checked the oil level and it was full and clean. The higher the RPMs, the lower the oil pressure. I slowed to 50 mph and when going up hills it normally easily "torques" @ that speed, I would have to down shift which caused the RPMs to increase and the oil pressure would bottom out. There were hills [small, normally] where the engine would begin to drop cylinders as the clattering increased. I would nervously keep an eye on the pressure gauge and pray that I soon would crest the hill so a shift to O.D. could be made, lowering the engine speed. By the time I drove into our driveway, the engine was missing and sounded like a number of people were hitting it with small hammers. OUCH!!! I was sick, but the truck got us home before giving up its life [or so I thought]. Unfortunately, our area does not have machine shops which the local reputable mechanics can trust. Consideration was being made into installing a remanufactured long block, but was not necessary, after all. A good friend [local FORD trained Diesel mechanic] agreed to work on the truck and I had it towed to his shop. I did not try to start it after returning from OK [we drove my wife's car] because I did not want to hear it "scream in pain", again. Several days later, my friend said he had started the engine and let it idle for some time and the initial lifter clicking abated after a while. He said it still showed extremely low oil pressure but otherwise sounded good. The oil pan was dropped and the pick-up screen was clogged. Now, let me provide some history. I purchased this truck about 9 years ago, with ~121K miles, from the elderly original owner. It had never been abused, but had not had regular maintenance. The oil was black with a Fram oil filter and the engine still had the original spark plug wires, radiator hoses, heater hoses, etc. Many vacuum hoses were missing or cracked. The engine bucked and the first 2 tanks of gasoline returned 8 - 11 mpg. When looking into the valve cover after removing the oil fill cap, one could see much sludge on the rockers. I began to reclaim the truck and did numerous "short interval" oil and filter changes using Rotella Diesel rated oil for its high detergent and high Zinc properties. The rockers are now clean and have been for a long time [years]. Earlier this year, when replacing the pushrod inspection cover gasket, I observed that that part of the engine was quite clean. So, in my mind, the engine internals must have been cleaned by the normal oil change intervals with good oil and filter [Motorcraft FL1A]. Apparently, WRONG! Just before the tow truck arrived, I checked the oil level, which had just been changed before the trip and was on the "calibrated by me" oil mark. It now was ~1/2 quart above the line??? A close inspection of the fuel pump looks like it has just begun to leak internally to the crankcase. The bottom of the oil pan had more crud than I would like to have seen. I am theorizing that sludge as seen on internal engine parts must have some "carbonized" part that does not dissolve with the detergents in the oil and just settles to the bottom of the pan and not flow out with hot oil changes. Anyway, the screen is covered with a metal baffle and maybe a 1/4 - 1/3 open area with no baffle. Looking under the baffle, it was full of black crud and there was some blockage of the non-covered screen. Maybe the leaking gasoline thinned the oil and introduced unwanted solvents which loosened the pan bottom crud. As engine speed increased [i normally go put-put; ask Gary], the loosened and softened sludge was sucked up and blocked the only open area of the oil pick-up screen, thereby blocking the oil flow? The oil pump has been replaced along with a new pick-up screen and tubing. The fuel pump has been replaced as well. While the pan was off, the raised areas which encircle the securing bolts, locating the original cork gasket, were ground smooth. This is a neat trick which enables one to install the 1 piece oil gasket, which Ford used on the later 4.9L engines, updating the 4 piece [leak prone] original. 6 quarts of 10W30 and a new FL1A oil filter and the engine sounds great and the oil pressure is back to normal. I will change the oil again in about 300 - 500 miles and have to regain my confidence by taking longer and faster trips, but as of the 24 hours I have had it back, all is well. Sorry for the very long post, but maybe this will help someone else. Link to comment Share on other sites More sharing options...
Gary Lewis Posted October 5, 2017 Share Posted October 5, 2017 Wow! What wonderful news!!! 🎉 I'm thinking you are right, that the gas softened the gunk that otherwise was stuck. (Like Lipitor does to blood globules?) And that gunk plugged the artery to the eye ...... Wait! I think I'm getting my stories mixed up. 😎 Which explains why the oil pressure went down with increasing RPM - there wasn't enough area through which to pull the amount of oil the pump wanted to move at the higher RPM. So a vacuum formed on the inlet to the pump and little oil was getting pumped. And since the lifters are usually the last to get oil, they were the first to complain. Once a lifter can't pump up it doesn't open when it is supposed to open nor lift as much as it should. So the power is down and the noise is up. Yippeee! Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted October 5, 2017 Share Posted October 5, 2017 David do these 300 trucks come with a phenolic or fiber timing gear? My truck came with a nylon tooth cam gear (for noise reduction) and when I had my pan off it took me a whole hour to pick all the plastic shards out of my pickup screen. Fortunately my engine is pretty clean inside because it gets a steady diet of diesel oil with all those detergents and the ubiquitous FL1A. Link to comment Share on other sites More sharing options...
reamer Posted October 5, 2017 Share Posted October 5, 2017 Reminds me of 1984, with my 1974 Bronco with a 302. Since I bought it, it had always burned oil, just acepted it that way. On a long trip, the temp went up and the oil pressure went down, and noise went up. Pulled of to the side of the Highway and put 2-3 qts of oil from my emergency stach and drove home. Funny, it never burned oil again......lasted years too! Link to comment Share on other sites More sharing options...
ctubutis Posted October 6, 2017 Share Posted October 6, 2017 Thank you for the explanation David! I was wondering what was up with that.... Link to comment Share on other sites More sharing options...
Ford F834 Posted October 6, 2017 Share Posted October 6, 2017 This is rockin' good news David, but also a sobering vicarious lesson for the rest of us. For as careful and meticulous as you are it is unthinkable that this would happen to you after that many years of careful maintenance. But it did... and could happen to any of us that have a vehicle where the PO neglected oil changes. I'm just glad your engine turned out to be "okay" even if it is worse for the wear. It is a good thing you turned around when you did, and I'm sure glad it got you home and wasn't any worse than it was! Link to comment Share on other sites More sharing options...
1986F150Six Posted October 6, 2017 Author Share Posted October 6, 2017 David, do these 300 trucks come with a phenolic or fiber timing gear? Yes. But, other than sludge, nothing was found in the bottom of the oil pan. Praise the Lord! Link to comment Share on other sites More sharing options...
Gary Lewis Posted October 6, 2017 Share Posted October 6, 2017 David, do these 300 trucks come with a phenolic or fiber timing gear? Yes. But, other than sludge, nothing was found in the bottom of the oil pan. Praise the Lord! That is excellent news! Link to comment Share on other sites More sharing options...
PetesPonies Posted October 8, 2017 Share Posted October 8, 2017 That is excellent news! Since the 240/300 series engines have no chain, it is a gear mesh. Fiber was used, but you can go with all metal. All metal is a little noisier, that's all. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted October 8, 2017 Share Posted October 8, 2017 Since the 240/300 series engines have no chain, it is a gear mesh. Fiber was used, but you can go with all metal. All metal is a little noisier, that's all. You can even get straight cut gears if you like that blower whine! David, you made the wise decision to turn back and I'm glad your mechanic was able to clean the pickup. Your new fuel pump should be good for another 100k. Link to comment Share on other sites More sharing options...
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