Potential Leak on Upper Engine Block (2.7l 4 Cyl)

I was looking around at my engine block, and it looks like there's some kind of oil stain or leak at the base of a hose on the top of my engine block nearest to the firewall. It's behind the air intake hose.

Anyone know what this hose does, or what that fluid is?

 

Is that the PCV? Looks like it, if so that'll be a little bit of engine oil. Might be time to check it or replace it. If you remove it the hose and PCV just be prepared for the rubber grommet the PCV sits on on the valve cover to possibly break up or fall apart. If you do replace it, just make sure to order a new grommet to put there as well.

 

Yeah that's ur Positive Crankcase ventilation valve aka pcv valve. That's nothing to worry about cause blow by oil and shit gets routed through that hose straight to the intake manifold to be burned off, one of the reasons why the intake can get so gummed up. You could put an oil catch can on that, it'll catch a few ounces and empty it out about every oil change or so. Any way, that's nothing to be concerned to much about.

 

Do I need to replace it? I just changed the oil about 400 miles ago. Truck has about 80,000 miles on it.
Thanks for the help!

 

With the engine running, remove the oil cap. Now place your hand somewhat over the oil fill hole. Do you feel a bit of air pushing out of there? If so, could be a sign of needing to change the PCV valve. Usually cheap and easy to do. Some do it as part of their baseline of their 'new' used vehicle.

Edit: you can remove the PCV valve easy enough and once it's in hand, given it a shake and listen for a rattle. That means the valve isn't gummed up and free and should be working correctly. If there is no rattle, than its gummed up or not functioning. I've had success just cleaning a plugged up one with carb cleaner, just spraying it out real well. But it should be cheap enough to replace if you want. I like to tinker, so I was curious about how well it could clean up and still function correctly.

 

Yeah no problem, you might need to replace it, do what cruiserguy said, that seems like a good way to check it. Its a pretty easy and cheap part to replace if it needs it. I will say, when I was putting in my catch can and I had that hose off of the intake the engine ran like shit! So if its bad and not getting the correct amount of vacuum to the intake, it might run funny too.

 

I think I'll just replace the PCV, thanks everyone!

 

No problem, luckily Toyota made that whole thing pretty simple and straight forward and in an accessible place so shouldn't be hard at all to do that.