Attention: TDR Forum Junkies 
I was accelerating hard up a slow grade, turbo boosting in the 20s. Timing is at 18 degrees with water injection too. Stock head gasket with stock bolts retorqued. Heard a pop or bang that sounded like my exhaust rattling so i ignored it until i noticed that my oil pressure which is usually near 60 psi at interstate speeds had dropped to around 50. I was in 3rd gear going about 65 mph, around 2,200 RPMs.
When i pulled over i found that my oil cap had blown off! I'm almost certain i had reinstalled it when i topped the oil off earlier, then again, there were kids playing all over my truck today, hard to say.
In stop and go driving oil was still returning to 60 psi, but at idle, where it is usually a little over 30 psi, it was down around 25. Otherwise, the engine felt just as powerful and healthy all the way home. There is some oil underneath which i assume to be from the crank case vent tube. A little more oil than i expected, left fresh drops in my driveway within 10 minutes. In fact, i think there is more oil under there than usual, but it is likely because i spilled a little today since i didn't use a funnel from the 1 gallon jug.
On the inside of the top of the oil filler neck, there is white foam. I imagine the oil filler cap could have been missing and debris could have collected, but i'm leaning more toward thinking it was on there and busted off. I was able to wipe my finger and a towel in it and get a bit of the goo out of the tube and saw that it was definitely white.
The dipstick looks a little watery above the oil full line. Tiny clear bubbles as if some water had misted there. Is it possible the water injection had dripped down that far? I looked in the overflow and the engine coolant is still green. With a very poor flashlight, i couldn't see any leaks on the engine. The tailpipe is bone dry, solid gray. I dabbed a tiny bit of oil via the dipstick into a small bowl tilted to see if there is any water separation over night.
I had mixed some oils, 1. 5 quarts of 10W-40, mostly Motocraft 15W-40, and another quart of Rotella 15W-40. I only mixed because i had a leak at the AFC for a few days and was using what i had to refill. The engine oil level is full to where i had left it earlier in the day. I'd be surprised if so, but could mixing have caused the foam? I seem to recall Motocraft using anti-foaming additive in their diesel oil but i don't remember what diesel oi foaming means.
I realize i've been pushing my head gasket to the limits and beyond. Do these signs definitely point to blowing the head gasket, or is this something else? Is it possible to blow the oil filler cap, even when snugly threaded on tight? Will the oil pressure read lower without a cap? What should be my next step in diagnosis? I'm planning to head out on an at leat 3,000 miles trip in just a day and a half. My boost is limited to 27 psi being wary of the head gasket, though most of my driving is near 5,000' elevation.
When i pulled over i found that my oil cap had blown off! I'm almost certain i had reinstalled it when i topped the oil off earlier, then again, there were kids playing all over my truck today, hard to say.
In stop and go driving oil was still returning to 60 psi, but at idle, where it is usually a little over 30 psi, it was down around 25. Otherwise, the engine felt just as powerful and healthy all the way home. There is some oil underneath which i assume to be from the crank case vent tube. A little more oil than i expected, left fresh drops in my driveway within 10 minutes. In fact, i think there is more oil under there than usual, but it is likely because i spilled a little today since i didn't use a funnel from the 1 gallon jug.
On the inside of the top of the oil filler neck, there is white foam. I imagine the oil filler cap could have been missing and debris could have collected, but i'm leaning more toward thinking it was on there and busted off. I was able to wipe my finger and a towel in it and get a bit of the goo out of the tube and saw that it was definitely white.
The dipstick looks a little watery above the oil full line. Tiny clear bubbles as if some water had misted there. Is it possible the water injection had dripped down that far? I looked in the overflow and the engine coolant is still green. With a very poor flashlight, i couldn't see any leaks on the engine. The tailpipe is bone dry, solid gray. I dabbed a tiny bit of oil via the dipstick into a small bowl tilted to see if there is any water separation over night.
I had mixed some oils, 1. 5 quarts of 10W-40, mostly Motocraft 15W-40, and another quart of Rotella 15W-40. I only mixed because i had a leak at the AFC for a few days and was using what i had to refill. The engine oil level is full to where i had left it earlier in the day. I'd be surprised if so, but could mixing have caused the foam? I seem to recall Motocraft using anti-foaming additive in their diesel oil but i don't remember what diesel oi foaming means.
I realize i've been pushing my head gasket to the limits and beyond. Do these signs definitely point to blowing the head gasket, or is this something else? Is it possible to blow the oil filler cap, even when snugly threaded on tight? Will the oil pressure read lower without a cap? What should be my next step in diagnosis? I'm planning to head out on an at leat 3,000 miles trip in just a day and a half. My boost is limited to 27 psi being wary of the head gasket, though most of my driving is near 5,000' elevation.
