I am just wondering why I would lost 5.5 gallons of oil in less than 75 miles, yet 2 days layer I fire it up and drive 60 miles and absolutely no oil is lost. Doesn't make sense..
OK, this morning hooked up the trailer and ran it around the drive and backed it up a small hill. OIL IS GUSHING OUT.
Does not appear to be from the High Pressure Oil system ....
It makes sense to me. When you lost the 5.5 gallons of oil in less than 75 miles, you were pulling a trailer. The engine was under load
. When you later test drove it on the freeway, you weren't pulling a trailer. The freeway was likely more or less flat. Your engine was not
under a real load. Later still, when you hooked the trailer back up, and then backed the trailer up hill, the engine was under load
The power that the engine needs to motivate a real load (truck and trailer) from a stand still up a hill, is enabled by fuel. In the 7.3L, more fuel per millisecond of the injector being open is delivered by increasing the oil pressure to the injectors. The higher the oil pressure, the higher the fuel pressure, the higher the fuel pressure, the more fuel is expressed into the cylinder, the more fuel, the more fire, the more fire, the more power.
From the Monday morning quarterbacking recliner where I sit, the correlation between your leaking operation and non leaking operation is straightforward.
However, the more you leak, the more you will leak, and eventually load will cease to matter, as the oil that has already passed through your leak at high pressure will have done enough damage to the seal in it's passing to now pass at lower and lower pressure. This is very common with an HPOP leak. It is the same failure modality I experienced with mine. No leak under no or light load, lots of leak under high load, eventual leak under any load, ultimately leak even at idle. And this cascade all happened within a very short period of time from discovery (less than 24 hours in my case).
You can poke and prod and hem and haw and guess all day as to where your leak is coming from. You can unbolt every part on the engine and replace every seal if you want to. But if you'd rather know exactly where your leak is coming from, without throwing parts, time, frustration, and more forum posts at the problem, then you need three ounces of diesel oil compatible Dye-Lite Tracer Dye, part number TP-3100, from Tracer Products
. This product was specifically approved by Ford and International for the 7.3L crankcase, and is chemically compatible with all the seals and gaskets and sealants contained in that motor as built. Use of the dye is how Ford directs service technicians to diagnose oil leaks in Ford's Workshop manual.
A professional leak detection light is called for to locate the leak once the dye is poured into the crankcase. That light used to cost over $300 twelve years ago. There are probably copies from China that are a lot cheaper now, but you don't need the professional light if you do the leak test at NIGHT. The lack of ambient light at nighttime greatly assists the human eye in detecting fluorescence. And if you use a black light
(black light bulbs in both compact fluorescent, tubular fluorescent, and incandescent in Edison screw base form factors are available at most hardware and home improvement stores), then you will have no trouble at all seeing the clear lime green effervescing stream of dye pouring from the leak source.
At that point, you will know with certainty where you leak is coming from.
I don't know what kind of oil you use, but I use full synthetic 5W-40. It costs $20.00 a gallon. So for me to lose 5.5 gallons on the roadway would mean a loss of $110.00... nevermind the guilt I'd feel about needlessly drowning the ground in oil. The cost of the tracer dye is negligible by comparison. And the time saved in diagnosis is worth even more. Highly recommended you start with the dye. If I had to place a bet, I'd say a plug seal on your HPOP gave out, so once your dye is in the crankcase and night has fallen, aim your blacklight at the HPOP first.