I have found my way to this thread due to the burnt oil smell in the passenger cabin issue we are having with our 2014 CX-9 AWD (58900 miles). I crawled under the car and reached up on top of the PTU and found the sludge and the smell. There was a lot of what I can best describe as grease on top of the PTU. I cleaned it all off with a ton of rags and made sure the vent was clear, then I cracked open the fill port on the PTU and no fluid came out. I really was not expecting any. However not having an electric pump I am finding I am not pulling very mush fluid out, much less than those using the electric pump method. I am wondering, Is this an assembly where I could spray in some type of detergent to break down the sludge and then suck it out?. The best I can hope for now is to fill it with the Mobile 75W-140 I purchased and drive it around for a couple hundred miles while I wait for the electric pump to show up via Amazon. If anyone has used a mild detergent before to break down the sludge inside let me know. Also has anyone replaced the PTU unit before and can give an idea of time required to replace working off jack stands.