When the car is on theres oil spitting out of the fill hole with the cap off. What can cause this? Arent you suppose to feal suction if you put your hand on the fill hole, instead of pressure coming out? Ive been reading around and so far all i see is something about crankcase pressure, and blowby but Im still fairly new to this so Im not really understanding whats going on. Any help will be greatly appreciated

 

Of course oil will be "spitting" out the fill hole if you take the cap off while the car is running. There are moving/spinning parts covered in oil right under the hole. Don't take your cap off while your car is running...

 

Yeah it seems like its a no brainer right. But my question wasn't answered about the air blowing out or not, is that suppose to happen? Like I stated before isn't there suppose to be suction?

 

There's nothing really complicated going on. Essentially you have a mess of moving components spinning away at high RPM's with oil being sprayed onto it, flinging oil everywhere.

Imagine a blender while it's on. If you take the entire cover off while it's on, your milkshake WILL exit the unit.

 

No, you will not see suction. Crankcase pressure gets vented to the head to be released back into the intake or atmosphere.

 

Don't think I'm retarded people I just didn't know if it was normal for air to blow out when the cap is off I understand completely that there is stuff moving and causes the oil to spit out. So to be positevly clear its normal for that to happen then right.

 

It's normal, the "wind" is being generated by all the moving parts in the head

 

Now go check your oil level and make sure you didn't let a couple quarts spit out of the oil fill

 

Lol!! No I didn't. The reason I even did it is because I was driving after a while of me recently putting more oil in. I started wondering if I had put the oil cap back on, because the wifey started smelling something burning. So I stoped and checked. Took the cap off and realized the air and tiny bit of oil spitting out. Thanx for the input guys.

 

That is completly normal. Now if you put your hand over the oil fill and it blows your hand off, then you have problems.

 

what kind of problems? cause thats what mine does...

 

The OP poses an interesting question. Most engines with a pcv valve contain a slight vacuum at idle. The Evo engine does not. Air blowing out of the filler cap, and my engine does this (always has), means the pcv valve is removing less air than what is leaking past the rings. Also, this means air is always moving through the hose that goes from the end of the valve cover to the intake.

So, the question arises, why have a pcv valve when the hose to the intake is always blowing air? My guess is that this is a EPA requirement. So, put on a tiny one (pcv valve), the Federal requirements are satisfied and let the rest of the blowby go to the intake.

 

Hey Rudy. Mine did that Superbad after my motor was built. Not so much after the catch can install. How many miles on your car?

 

I lol'd.

 

I think I'm gonna hit 80k amd I might have been over reacting at the time lol!! Some of the posters explained pretty well, I need to get a AOS but seems ithe car decided to start giving issues again so gonna have to wait