been losing a lot of oil and not a drop is on the ground. we're talking a quart every 2 tanks of gas, maybe more. oddly there is no tell-tale blue smoke and it doesn't smell like it either. a good amount of oily, cruddy buildup on the plugs. i have good, pretty even compression, so i'm guessing valve stem seals. i didn't know just how much oil it was losing until i saw the oil pressure was lower than usual, and it took 2 quarts - yikes! i keep topping off, but on friday it started making a HORRI