Believed it came in through the rear main seal. When i lost oil pressure I turned off the engine and was able to get towed home. I tore the engine completely down for inspection and a really good cleaning. The pistons and valves have a lot of carb build up on them. # 6 piston is the worst and the build up gets less as you move up to #1 piston. Any ideas what would cause this build up? The motor has about 7,000 miles it. 2000 Wrangler
Icon 944 pistons, .020
Camp cam 163-000-5
rocker arms are shimmed
stock exhaust
Ford 24 lb injectors
I did not assembly the motor so I do not know what valve springs were used.