LUVTruck.com

My buddy has a 93 isuzu pickup that is idling really low and the engine is about to vibrate off the motor mounts it seems. It is still running but not very well at all. I took the engine oil cap off of the valve cover and on the inside of it there were lots of white bubbles and what looked to be chocolate milk. I checked the oil on the dipstick and it looks fine. Upon startup the engine smokes a little then stops. When you are driving it doesnt smoke at all, at least up to 40mph because that is the fastest we feel safe driving it. At a stoplight tho it begins to smoke. Blown Headgasket? Cracked Block? Crack in cylinder wall? I want some input before I start tearing this thing apart