no pressure test. i just thought of something though...i think he generally lets his car warm up before he drives it. ive had to use his truck for several things before, and he'd always tell me to let it warm up for a few minutes before driving it (which i never did lol). ill ask him if he still does that, and ill let him know about everything else.

 

You said you changed the oil. did the oil look bad, like the same color, or was it black? if you have antifreeze in the oil it will tear up your main and con rod bearings real quick. I have a chevy blazer that will tell you that. if thats the case i wouldnt drive it until you figure out how its getting in there and get it fixed.