Linda S is from the same part of Calif. and has seen my rig last year before this problem and knows me enough to assure you I'm 100% mentally ok. I'm not offended but perplexed as much as you experts are. Your right in saying the snake oil and PCV valve should not have worked and there should have been a Blue Angels style trail of smoke and a puddle under the motor but results don't lie and neither do I when I tell you I have had no blue smoke trails nor puddles under this rig. A little oil sweat around the valve cover yes,........... normal with 73,000 miles right? With the main seal gone does it burn oil blue or just out the pipe as a mist like I have had before I addressed this oil usage? I really can't tell you at this moment the oil usage is stopped permanently but hope it is! In the tankful I ran after the change of oil, the additive added and PCV valve changed I noticed a drastic drop in oil usage as in the dipstick level did not alter, also no black sooty mist out the pipe. The rig is parked as I'm out of the country till Sept. when we all shall see if this was a quick temp. fix or permanent. Till then all we can do is speculate and discuss this. I do thank you for your opinions and suggestions. If a tear down is avoided through these simple measures than good for me and worth a try to you out there, no? I spent $25 on the additive and PCV valve, if that fixed it I saved hundreds! I'll tell you I was so troubled by this oil usage coming from Louisiana to Calif. having to have extra quarts of oil in the rv and adding at every gas fill up that I was expecting a main engine repair. I got online and looked up "valve seal leakage" repair videos and there was a nutty guy promoting the wonders of just replacing a $5 PCV valve that may save you hundreds in repairs so before tearing into that motor try this and so I did. I also shopped at the Oreilys Auto parts store and looked for a valve seal stop leak product and applied that $21 a quart to my oil change with 10w40 oil and it worked for that tankful before parking it for the winter and summer 2016 so we will see in Sept. if it was permanent. I have a friend starting it and taking it for a spin around the block once a month to keep things lubed, meanwhile I'll keep the fingers crossed.