What is the rubber gasket under the throttle body top plate for/do. What is that part of the throttle body for? My gasket is kind of deformed and sagging. Is it ok if it is not tight? The area has some oil in it I assume from the valve cover vent tube.

Thanks.

 

The gasket ensures that un-metered air does not enter the TB under the plastic cover, nothing more than that.

The oil is coming from the right side valve cover area through the tube, this is rather normal if the amount is small. You can buy a filter at any parts house that plugs into the rubber grommet on the cover then to the hose. This has kept my TB spotless.

 

So if gasket doesn’t fit right could that cause un-metered air to get in causing my lean condition to come and go?

Thanks for the info.

 

Yes, that is the fresh air intake for the PCV system. The top plate is removable so you can clean it out if it gets oil inside of it.

So if you think the gasket isn't sealing, then yes it could be a source of unmetered air. I'm pretty sure that causes a lean condition.

When I got my car, I actually suspected that I had 2 leaks. One was a dry rotted elbow on the throttle body for the evap system, just below that PCV hose. The other was the grommet in the top of the valve cover for that PCV air hose that seemed kind of loose to me.

 

funny a lil while ago i opened that cover up and cleaned out that gasket and that area... figured getting rid of that gunk would do good but i had no idea what it would do lol