Oil in air intake/resonator box - problem? (1 Viewer)

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Just purchased a 2000 LC100 that has led a rough life with its previous owners. Temp gauge in the dash wasn't working, so I removed the air intake/resonator between the air filter box and the throttle body to get at the temp sender, and when I pulled the air intake/resonator, about two tablespoons (30 mL) of oil poured out of one of the vacuum ports. I am trying for the life of me to figure out how oil got into the resonator. Is this normal? If not, any idea on what is causing this and what it portends? TIA.
 
I'd wager your PCV valve is clogged up. Once that happens it can push oil out into the vacuum lines and intake. Clean or replace the pcv valve. The old grommet on the PCV valve may need replacing as well. They turn to plastic after a while.

Good time to clean the MAF sensor and check your vacuum hoses as well. Run a quality fuel treatment through it - I'm partial to BG44K.
 
@Zen Anger

There's a very good chance the PCV grommet will be like ceramic and you may not be able to get the PCV valve out. There are 2 ways to combat this. First, try removing the valve with the engine blazing hot, which will soften the grommet. The other method is to just pull the valve covers and replace the gaskets, and then replaced the PCV grommet/valve at the same time. There's a good chance your valve cover gaskets are leaking due to age/miles.

Many folks (me, for sure), while trying to replace the PCV grommet, end up shattering it and having pieces drop inside the valve cover. These pieces are retained in the cover, but aren't great to have floating around inside. By pulling the VC, you gain a lot of access to get the bits out.
 
I'd wager your PCV valve is clogged up. Once that happens it can push oil out into the vacuum lines and intake. Clean or replace the pcv valve. The old grommet on the PCV valve may need replacing as well. They turn to plastic after a while.

Good time to clean the MAF sensor and check your vacuum hoses as well. Run a quality fuel treatment through it - I'm partial to BG44K.
Thanks for the advice - looks like I have another project to tackle this weekend!

EDIT/FOLLOW-UP:

Finally got the PCV valve and grommet in the mail yesterday. As aptly predicted by @Zuberg @SteveH, the previous grommet had turned into brittle plastic and broke into five pieces, two of which fell into the valve cover when I attempted to gently remove the grommet. Had to spend 45+ minutes fishing them out with tweezers, needle-nose pliers, and one of those graspers, but was able to recover both pieces. Confirmed all pieces in hand formed a complete grommet.
 
Last edited:
@Zen Anger

There's a very good chance the PCV grommet will be like ceramic and you may not be able to get the PCV valve out. There are 2 ways to combat this. First, try removing the valve with the engine blazing hot, which will soften the grommet. The other method is to just pull the valve covers and replace the gaskets, and then replaced the PCV grommet/valve at the same time. There's a good chance your valve cover gaskets are leaking due to age/miles.

Many folks (me, for sure), while trying to replace the PCV grommet, end up shattering it and having pieces drop inside the valve cover. These pieces are retained in the cover, but aren't great to have floating around inside. By pulling the VC, you gain a lot of access to get the bits out.
Thanks for the heads-up. I specifically looked at the valve cover gaskets to see if there were any obvious leaks, and there were none - so hopefully the PCV grommet will miraculously be pliable and give me no problems (dare to dream!). If not, looks like I may be doing some preventative maintenance on the valve cover gaskets per your recommendation.
 

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