Stuck in Commiefornia...
Join Date: Dec 2008
Location: Clearfield, Utah
Thanked 447 Times in 315 Posts
Head gaskets. Used to experience the same symptoms with 5.0L Mustangs with superchargers on them when they'd fail the gaskets. The gaskets fail in the perimeter of the cylinder, the area known as the "fire ring" prior to the change to MLS technology. Compression from the cylinder is passed by the gaskets into the cooling system, they end up in the head and this allows the head to overheat, when load drops, the gasses passing the gasket slo, the coolant does its job again but it gets really hot and stays that way.
The Current Truck (Oct-2013 to Present):
1999 (Early) F-350 Lariat, CCLB, SRW, Black/Tan
7.3L Powerstroke, 4R100, 4x4, 3.73, 37x13.50-18s, '05 Axle Swap, 6" Fabtech lift, GTP38 "D66" turbo upgrade, SCT 4-position chip with custom tuning by me, Straight Piped 4" down pipe through 5" dual stacks, N-Fab full length triple steps, Pro-Tech cab guard and tool box, louvered 5th wheel gate, Hella 500 Fog and Driving lamps, much more to come...
The one I'll miss, (Mar-2009 to Jan-2014):
2000 Excursion XLT 4x4
6.8L V-10, 4R100, 4.30, 285/75-18, 271whp / 388wtq
The one I won't, (Jul-2005 to Sep-2012):
2005 F-350 XLT, CCLB, SRW, 4x4 FX4
6.0L PSD, ZF-6S650, 3.73, 35x12.5-18, 4.5" Lift