What Is This?

[emim]

Hi all... I just changed my air filter and noticed this part that looks like it's leaking something.. Does anyone know what it is and should I be concerned about it? It's a 2006 400h..Thanks.

[maseace]

That's the "Mass Air Flow Meter" which should only have air passing underneath it. That could be a drop of oil from something else?

[cduluk]

My guess is that there's a little moisture in the air going through that area, and what you see is that moisture (water, oils) condensing and seeping out. This happens to my A/C system often; right around the vents on the dash i'll see a similar "stain".

If you open the air filter box, my guess is that you'll find an oily residue covering the plastic.

I have the same stains on that part on my Rx400h, 2008 with 67k miles.

Has anyone ever "detailed" your engine bay? Sometimes people will rub some type of Armor-all or tire shine on the black plastic inside of the engine. If any of that shiny stuff got into the crevasses around that part, any air that pushes out from inside that part will push the shiny stuff out and leave a spill similar to what you see. I know i've done it to mine, so that's another possibility. Either way, i don't think it's anything to be concerned about. <_<

[emim]

Whew.... Thanks guys.. I get panicky when I start to see "oily" stuff around....I've never armor all'd the engine area... But I will look inside the air filter this wknd....

[Jim Nazium]

Actually, I believe your answer is in the Air Filter you are using...

I noticed you are using a K&N air filter. Those filters require to be "oiled" as part of there air filtration characteristics. And, as a rule, more is not better. The filters when new come pre-oiled. When they are serviced, they are washed with the appropriate air filter cleaner, and then allowed to dry. Then, you are to re-oil the K&N air filter with the appropriate Oil. I believe the air filter was over oiled and therefore appears in the form of "oil sweating" through a seal or component (that being the mass air flow meter).

I would suggest you open up the air filter box, and wipe everything down to remove any excess air filter oil.

Cheers,

MadloR

[emim]

Actually, I believe your answer is in the Air Filter you are using...

I noticed you are using a K&N air filter. Those filters require to be "oiled" as part of there air filtration characteristics. And, as a rule, more is not better. The filters when new come pre-oiled. When they are serviced, they are washed with the appropriate air filter cleaner, and then allowed to dry. Then, you are to re-oil the K&N air filter with the appropriate Oil. I believe the air filter was over oiled and therefore appears in the form of "oil sweating" through a seal or component (that being the mass air flow meter).

I would suggest you open up the air filter box, and wipe everything down to remove any excess air filter oil.

Cheers,

MadloR

That makes sense.. But I just installed the filter, new out of the box... Maybe it had too much oil on it; I will open it up and take a look to see what the inside is like.

[lemon]

If you 'just' installed the K&N, then I doubt the stain would appear that quickly. However, as someone pointed out, K&N filters that are over oiled can cause all sorts of trouble, especially if oil gets on the MAF sensor.

Also, just so you know, there is some evidence out there that K&N filters let more contaminants through than a regular air filter.

[riwyle]

Since the MAF sensor is sealed from the air flow by an o-ring and the air duct is at negative pressure anytime the engine is running, I see no way that oil from the air filter would deposit as shown in your picture.

[Jim Nazium]

Well, the fact remains, that K&N air filters contain oil as part of there filtering properties. That "stain", looks an awful lot like oil to me, and the only way oil would appear after the air filter, along the air box and through to the way to the MAF... is from the K&N air filter. Period.

Clean it out, with isopropyl alcohol (diluted, or less than 50% concentration) the air box and air housing. Pat down the air filter with Paper towels, and blow dry it with a hair dryer. Remove the K&N air filter sticker. And if the problem persists, put back the factory air filter and have the stealer look at it for you if you find it somehow is affecting the performance of your vehicle.

Cheers,

MadloR