Oil in GX "B" Filter Only--Why?

[edo]

Maybe someone can help explain an observation. Last night I performed the 20 k mi 1B service on my new '09 GX, by draining the "A" filter and replacing the "B" filter in addition to other services. When I removed the plug on the A filter I found it to be dry as a bone, not a drop of anything present. I replaced the plug with the new o-ring and moved to the "B" filter. When I opened the "B" filter I was very surprised to have about a tsp of clear light machine oil in the bottom (some which spilled on me) of the filter cup. The oil smelled like sweet onions, I suspect it picked up its scent from contact with the gas. The question is why the A filter is completely dry whereas the B filter was wet with oil? I suspect this is why Honda wants the B filter replaced at 20K, and may be due to the expansion of the gas to a lower pressure (I presume) at the "B" filter allowing the oil to somehow come out of suspension in the gas. Am I correct, or do I have a problem with the car? BTW, I replaced the B filter and O-Ring which was easy enough, but there isn't much room for a torque wrench at the "B" filter. Thanks

[Amfuel]

Re: Oil in GX "B" Filter Only--Why?

Oil in the filter is from your fueling station.

[Lakewood90712]

Re: Oil in GX "B" Filter Only--Why?

Your car is normal . Exact same results on both my 01 and 08, (Usually a lot more than a spoonfull of oil). Things do tend to seperate from a gas dueing a pressure drop ( expansion).

[cngmike]

Re: Oil in GX "B" Filter Only--Why?

I don't know the science behind this but it is easier to coalesce at lower pressure.

[Surfdancer]

Re: Oil in GX "B" Filter Only--Why?

My lab and vehicle test experience shows that most oil is dissolved in CNG. When it suddenly drops in pressure and temperature, it can (and will) precipitate out of the low pressure gas stream as an aerosol. Then it can easily be collected in a coalescing filter (or the low pressure side of the fuel pressure regulator).

[edo]

Re: Oil in GX "B" Filter Only--Why?

Thanks to you all. I just wanted to ensure I didn't have an "A" filter problem somehow. BTW, if anyone has any tricks to share re getting a torque wrench (in-lbs-click type) on the "B" filter via 24mm socket I'm all ears. Thanks.

[sjseng]

Re: Oil in GX "B" Filter Only--Why?

I just changed my A and B filter. Very slight fluid in A and none in the B filter

For the torque wrench, I just used a short extension on the socket to get the wrench away from engine block and worked fine. Only had a short throw, but it worked. My biggest issue was the o-ring on the housing. It took me several tries and freezing multiple times before it finally worked. Then the housing kept acting like it was cross threading. Don't know if I'll do that again. I think I will be streatching out my changing limits though as there was very little if any fluid and both filters looked just like the new ones. And that was with about 25k to 30k miles on them.