So I just bought a 1997 Toyota 4Runner Limited 4WD. Everything looked good on it. I get it home today and realized something was leaking under the intake box. I pull the air filter out and the bottom of the intake box and part of the bottom of the filter is covered in oil. What is causing this oil to come down the intake? Bad PCV valve? Help please, I am brand new to Toyota's.

 

Did the previous owner run an Amsoil foam/oil air filter? From the sounds of it, you just described my airbox...

Is there oil in the intake tube, also? If not, I suspect a foam/oil air filter was used.

Steve.

 

No there is oil up in the intake. Since it is slated down it runs down the intake tube, opposite direction of air flow and is leaking into bottom of air box and then through it and down the side of the engine bay and down onto the ground.

 

Wow, I was hoping along with you that this might be something simple. Grasping at the simple things, I can't see how this could be a simple case of overfilling the motor oil. It does sound serious...

There are some serious mechanics on this board. Hopefully, you will hear some good info from them.

Steve.

 

could be what you said or maybe even worse. I'd change the oil while someone can tell you the exact problem. good luck.

 

could be a bad head gasket. time to test coolant for exhaust gasses
and oil for coolant

 

PCV System.... but due to the dripping you say..... prolly blow by from the cylinders or someone metioned over fill... thats possible... Is it smoking any at all? Check oil level on dip stick......

 

Nope, doesn't smoke at all. It runs real good. I noticed some of the PCV hoses are pretty gummy. Could be overfilled, I think I will drain the oil completley, need to do oil change anyway, then fill it to correct level. If it then persists I'll check into PCV system.

 

I'd seafoam it with a quickness

 

I'd clean the intake and change the PCV valve.

 

There's also a non-PCV valve hose that enters the intake track pre-throttle body. That may be creating oil in the tube as well. But I don't think I have ever seen it get all the way to the air filter - and I have owned 6 5VZFE-powered vehicles. I find it very strange that the oil made it past the J-tube (just before the intake box, underside of the tube). Can you post a picture or two for us?

 

I will post a pic tonight. From everything I have read seems that whenever someone has oil in airbox is almost always related to PCV valve, that goes for all automobiles. Where exactly is the PCV valve on a 1997 Toyota 4Runner?

 

This is a picture from my O Gasket thread (in my sig). Anyway, see that hose on the right kind of low in the picture? The PCV valve is at the end of it on the valve cover.

 

@ TripleDright on top of the ignition coil on the passenger side closest to you..first tube you see...

 

Now I have to check. I checked my air filter yesterday and I noticed some oil residue in my airbox too. I do have a K&N, and I am very careful about over oiling it, and when I do oil it, I use a regular filter for a few days while I let the K&N sit out and check for it dripping oil while its out of the airbox.

Anyway, I am going to clean the MAF and throttle body tomorrow so I will see what I find along the intake tube.

 

Two questions: I disconnected my air box and intake to the TB to check it out for an oil trail. There was a residue from the TB to the airbox, with some buildup at the bottom of the airbox, but very minimal. I cleaned out my TB while having it all out and cleaned out the airbox too. That's when I noticed something interesting. The airbox has a few small holes on the bottom. Is this for expected drainage of blow by?
Assuming that the oily residue I have is blow by, is some blow by normal?

My truck has 62K on it and I have been very diligent on repairs and fluids so I am just trying to determine if I need to worry about engine issues down the road. Thanks!

 

So the oil is coming from the non PCV hose pre throttle body. Which means it is coming up out of the drivers side valve cover area. Does this mean there is excess crank case pressure, which means bad rings?

 

The holes at the bottom of the airbox are there to drain water if water should get in.
Most likely have a bad pcv valve.
One other thing to check, I saw this on a mazda v6 once, someone had changed the valve cover gaskets and on one of the valve covers the top part of the gasket fell out creating a huge vacum leak into the valve cover which sucked oil through a pcv hose into the intake. On the 4runner, drivers side valve cover there is a hose at the rear that comes up to the intake, runs through a metal pipe then through another hose that goes into the intake tube near the throttle body, firewall side; you might check that hose for oil.

 

This is where the oil is coming from. I did notice someone has mucked with it, the front right screw on the valve cover someone cracked the ear of it and then JB welded the crack and there is also JB weld around that front right spark plug. SO I wonder if there is a vacuum leak there and thats causing the oil to get sucked up into that tube and dumped into the intake before the throttle body.

 

sounds like you need a new valve cover and pcv valve may be you would be inclined to get a new tube for that as well?? new valve cover gaskets for both sides and not too bad a cost on that fix