Grey sludge

[cousindave]

I have now calmed down and started the rear main seal again. I removed theoil pan and there was a little bit of grey sludge at the bottom. I looked at the oil in the bucket and oil looks clean. Could i have a head gasket leak?

[LaneRover]

Total stab in the dark here but - do you drive this truck a lot for longish (more than a few miles) distances? Or has it been sitting where the temps vary greatly and in a damp environment?

If not could it be the result of condensation in the engine and not a head gasket leak?

[cousindave]

Well, about a month ago i replaced the rear main seal only to notice it leaked and the engine overhdating. I flushed radiator and.block still overheating. Removed stat still overheating. Checked compression and all pressures fine. So i finally put a thermometer in the radiator and thermometer read 135°, which lead me to believe it was a a broken gauge. So, really it only ran for about 30 minutes on fresh oil. Now i remove pan and theres a trace of grey sludge.