My 98 F-150 4.6 just turned 185,000 miles and it's burning oil all the sudden.
I bought it new and changed the oil every 4,000 miles without fail. This truck has had all the maintenance required and more. In the last 5,000 miles I had to add 3 quarts of oil. The exhaust isn't smoking and there's no oil stain on the garage floor. I realize normal wear can be the reason. I wonder if there might be some other cause I can look for. Any help would be appreciated.

 

I'd say start with replacing the PCV valve it's cheap and might solve the problem.

 

Yeah, and get it from Ford. It'll cost a bit more but they seem to work far better..

 

I bought a new PCV Valve from Autozone. I should know better.
My understanding is that it is an air flow check valve. When I removed the existing one it was fairly clean, it did rattle and I could only blow through it in one direction. (Crankcase Out). The one I got from Autozone ($3.50) I could blow (Crankcase in) with resistance and crankcase out without resistance. Isn't it supposed to be air tight toward the crankcase.

 

My dad told me that when I replace mine to get it from the dealer. I plan on doing it soon as I am nearing 200k miles and I have put 30k on since I got the truck. All I know is my PCV has upwards of 50K+ miles.