Check your air filter.......if it is dirty/restricted your engine may have been breathing through that hole (would also explain the drop in MPG when you reconnected the PVC hose, and possibly that exhaust note). That hose is where the PVC system draws it's air from (so it has a clean source after the air filter).

 

I'll check the air filter. It's a K&N filter that's about 30k miles old. It didnt seem all that dirty.

I thought that tube was where the crankcase expels its excess gasses back into the intake where its recycled back into the engine to be burnt off?

 

I'll check the air filter. It's a K&N filter that's about 30k miles old. It didnt seem all that dirty.

I thought that tube was where the crankcase expels its excess gasses back into the intake where its recycled back into the engine to be burnt off?[/QUOTE]

Nope, the vacuum port just behind the throttle plate is where the PCV vapors are introduced into the intake, it draws through the PVC valve and that hose is to ensure a filtered air source for the system.

 

Check the breather valve. the backpressure was probably the reason, why the hose popped off the first place.
The crank case ventilation is there to let the air out of the crank case area, when the pistons going down. If the ventilation is clogged up, the pistons bouncing basically on a air-bolster, like you hit on a balloon. This makes the engine work harder and this can cause your problems.

 

i believe guy nailed it.

 

how can i check the breather valve and what should I be looking for exactly that would indicate a clog? Sorry i'm a bit of a rookie here.

 

oh- ok- you can't really check it- only if you take it out and blow in it and see, if it's clogged up. mostly it's full of oil- they are not expensive and it's never a mistake to replace it from time to time- The valve is actually a filter, which filters the oil-heavy air before it goes into the air filter box or sometimes into the intake directly- depending on the system. you might as well take the air box out and blow through the connection- if you can't blow through, it's clogged up.

 

okay thanks. Is this a case where an OEM part would be best or will an aftermarket replacement from autozone be sufficient?

 

I believe thunderhorse already found what aftermarket brand is the OEM one. Regardless I'm sure any brand would be fine considering what type of part we are talking about lol!

 

Okay so I've replaced the pcv valve as suggested. Just to make sure I understand, please have a glance at the attached pictures. The vent hose connected next to the engine oil filler circled in green on the right and the connects to the air filter box circled in green on the left. The pcv valve is what I replaced and is circled in red. I've also included a picture of the old valve...looks pretty clean to me.

One additional note...one side of the top piece of the air box (right side without the metal clips) was not hooked on properly and thus there was a bad seal for the air box. Would this have caused issues? I see I takes with no box at all so I'm not sure if that's it.

 

Forgot the other pic.

 

you look at the spring and pintle and not inside the chamber.
the other question, I don't know, what you mean. A closer picture would be helpful. if the air box is not completely closed doesn't matter. the air box is just for the air filter. the engine runs without box too.


does it work now?

 

... and that hose is to ensure a filtered air source for the system.

I didn't think that the hose the OP circled was involved with gasses from the crankcase ... that hose is the one from from the EGR valve to the vacuum port after the throttle valve as you pointed out.

You also point out that the hose originally pointed out is a 'filtered air source for the system'.
Can you tell me what parts of the system use this filtered air?

 

https://www.google.com/search?q=pcv...&sa=X&sqi=2&ved=0ahUKEwiet5WCwMDQAhVBwYMKHWE1A94Q_AUIBygC#imgrc=qZNSkj0NVOeT6M:

 

I didn't know that but it makes perfect sense. Thanks catch 22!