Help! Leak at oil filter cap / housing

[Tyler]

Did an oil change, start the truck, see a pretty significant class III leak. It’s at the oil filter housing / cap.

I figure the new o-ring that came with the new filter (Mobil 1) is bad, so I went out and bought another whole filter kit ($$ lol). The new o-ring didn’t work either, and neither o-ring looked bad anyway.

The plastic filter cap threads or the threads inside the housing are damaged, I assume. I did a thorough cleaning and inspection of both areas and no visible damaged threads.

So, wtf is the problem, I’m thinking? Can the plastic filter cap get warped from heat or from tightening it too much? Is my cap warped?

I kind of felt defeated and also hoped it would be the $40 plastic cap and not the aluminum housing attached to the engine. My plan was to order a new one and see what happens.

I put everything back together so nothing would drip on the driveway and figured let me turn the truck on one more time to have a look.

Guess what? It did end up being the plastic cap but not in the way I expected. It seems to be leaking out of a small crack in the plastic, which wasn’t as obvious the first time, but now shown clearly in the photo below.

I’ll try to get the new cap this weekend if Toyota has them in stock. Just posting for anyone’s future searches.

 

[Mike Z]

MotivX tools work great, especially the drain fitting and hose.

One thing you have to be careful of is when you install the large O'ring on the housing, make sure it is in the correct place. Also, the factory filters are reasonably price so I would not bother with aftermarket.

 

[Tomahawk Dog]

When installing or changing the filter do not over tighten.
It is a plastic part you can damage it.
The O ring is what seals the filter cap not the threads.

It will always seem harder to remove than install,
this is normal as the O ring is holding a seal and it is at a higher temperature when removing.

Temperature affects contact tension. The plastic cap expands when warm (removing) and contracts when cool (installing).
Nature of the Beast!