Oil on intake plenum?

jreask

jreask

Member
I have a 1999 4Runner Highlander that I'm looking at purchasing. It has about a four inch square spot of oil on top of the intake and some thicker spots between the upper and lower intake. I don't know where this could be coming from? It almost looks like it was blown up to the top. Anyone have any ideas? Thanks in advance for your help


I'll try to get a pic tomorrow.


Joe
 
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Any picture?

Remove the hose that connects the blow-by to the intake (between the throttle body and air filter box). If it contains lots and lots of oil, the engine has excessive blow-by, meaning cylinder compression is leaking to the oil pan.

I recently helped my neighbor to buy an 03 tacoma with 5VZFE (89,000 miles). It too had oil right on top of the throttle body. I noticed the owner had a K&N (now in trash!) installed in wrong direction!.
 
I am having the same exact problem. I couldn't find a solution, hopefully you have better luck. I heard it is normal to have oil there but not sure how much. I wasn't sure if the amount I had is normal or too much. Only answer I could get from here is the piston rings may be bad...My truck doesn't any smoke so I stopped looking
 
There was a slight coating of oil inside the upper plenum after the throttle body,nothing major. The hoses are clean. The most oil is between the upper and middle aluminum plenums. I'm away on vacation so l will try to get a pic this weekend.
 
4Runner4TW said:
Here is a link to the thread I started on this with pictures. I determined the oil is from that breather hose attached to the intake. Does yours look anything like the first picture?
http://www.toyota-4runner.org/3rd-gen-t4rs/140850-oil-tb-vacuum-hose.html
Click to expand...

No, mine is actually between the upper and middle aluminum plenums AFTER the throttle body. The hose BEFORE the TB is clean with only a slight amount of oil on it. I'm going to remove the upper intake this weekend and see what I can find. I do know that the PCV valve was clogged before I removed the TB and cleaned it.
 
Buying another 3rd gen Joe? Didn't you change out a TB/H20 pump not too long ago?

If the PCV has been clogged at some time in its life, then the valve seals on that bank may be leaking. Replace the PCV with an OEM one; if that does not do the trick, think about performing a compression test.
 
Yes I did change a TB/WP in another 4Runner. It's a hobby for me. I buy and sell after I get them in good running condition. I now have found a 99 4Runner Highlander that's in decent shape I think.
As far as the oil BETWEEN the plenums, the vacuum lines were pretty clean and the upper plenum had a very thin layer of oil in it. The biggest part was on the FRONT OF THE OUTSIDE of the upper plenum and BETWEEN the upper and middle plenums. It almost looks like the oil was blown between the two halves of the plenums from somewhere near the front of the motor. Possibly behind the upper timing cover? The spot on the front of the upper half of the plenum was right above the oil filler cap. The valve covers are completely clean (the parts I can see). I'll take the plenum apart this weekend and see what I can find.
 
The gasket between the manifolds may have a tear in it. If the tear is big enough, it will effect vacuum (idle for example) but is easily repairable.

At worst case the driver's side cam seal is leaking. You can always replace the oil cap seal (it is $2~3 at the dealer) for the heck of it.

Post some pics.

I got to ask how big your post repair profit margin can be on resale (ballparking it)?
 
LittleCaesar said:
The gasket between the manifolds may have a tear in it. If the tear is big enough, it will effect vacuum (idle for example) but is easily repairable.

At worst case the driver's side cam seal is leaking. You can always replace the oil cap seal (it is $2~3 at the dealer) for the heck of it.

Post some pics.

I got to ask how big your post repair profit margin can be on resale (ballparking it)?
Click to expand...

The truck runs great with MAYBE a little power loss. I'll get some pics this weekend.
My profits aren't good. It's more of a hobby. The most I ever make is $2000.00 The least I ever made was -$400. LOL
USUALLY I MAKE ABOUT $700-$800.
The 1999-2001 5 Speeds are the easiest sell. I have NEVER had to show one more than once. Of course, good running 4Runners sell themselves.
 
That is not bad. If you could turn over at least ten a year, the numbers speak for themselves.

If you repair that many, I'd definitely look into a code reader that provides code reading along with live data.

Will be waiting for the pics.
 
I second for pics. I thought we were having the same problem but I guess its different areas. Im still curious to what it is though.
 
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