Here we go again. I've been dealing with a 2001 F350 that hates me for about a year now. Problem is--oil consumption. Have tried everything except one thing that just does not make sense to me. Performance is excellent. Replaced all injectors/injector o-rings you name it I've done it. A tech at a local diesel shop said he thought it might be the HPOP front seal allowing oil to be sucked out of the system. My question is, is this possible and, sucking it out to where?? I didn't think there was a place that the oil and fuel could mix in this type of pump. Anybody ever heard of such a thing? Oil consumption is about a quart every 200 miles. The truck does have 208,000 on it but, this oil use still seems excessive for a well maintained truck. Blow-by does not seems excessive. You can put the oil fill cap upside down on the fill tube and, it stays there, isn't pushed off by pressure. There is NO leaks causing oil to hit the ground. Dye has been put in the motor to find any external leaks, none were found. Any ideas?