rukkus0o

Hey all. New member here, joined the board to see if I could get some insight from 4 runner owners about my issue. The truck is a 2000 with 112,345 miles on her.
Somehow I am getting oil up into my intake. First noticed the issue after a stint of about 30 mins on the highway at about 70mph. Came home, went in the house, and the following morning at startup I got a puff of smoke out of the exhaust. This progressed over the last few months. Finally got time today to dig into the issue to try and figure it out.
Changed the pcv with no results. Today took apart the intake tube and upper half of the intake manifold to find this...

Solid amount of oil laying in the intake runners. Also a large amount of oil was in the bottom of the intake resonator box, which I had to drain out.
Checked all of the incomming vaccum lines and narrowed it down to what I think could only be two possibilities. Either the upper hose which comes off of the back driver side of the cylinder head or the pcv valve hose. I popped the back hose off at idle and that seems to be sucking, not pushing air out so not sure oil could be evacuating that way.


The truck idles and runs fine around town. Just after highway jaunts at above 70mph does she smoke after a cool down and refire. I also noticed at times what one would think was detonation or spark plug knock right after getting off the highway and pulling away from a stoplight. At first I thought valve seats were the issue, but then there shouldnt be oil up in the intake.
The only other reason I can think of would be blow by. Some other curious symptoms which have developed is a loss of overall acceleration and occationally right after startup the truck will hesitate no matter how far you push the throttle for about 50 seconds then it idles up and is fine.
Sorry for the long post, just wanted to get all of the info I've gathered into it. Any insight and direction you guys can give me would be mush appreciated!!!!!!!

98LimitedT4R

Is it possible that your truck was a rollover before, or did you get a replacement engine ever? I see this in rollovers often. Air intake full of oil, up to the manifold.

just call me smithy

have you checked the oil level, you may have to much in, also i think you need those vacume lines, some one corect me if im wrong

rukkus0o

Nope never in a rollover or have I even gotten close to doing mild offroading with the truck yet.
She's a street queen my wife drives.

Oil level is good, and over time drops b/c the oil is being pulled into the intake somehow and then being pulled into the engine, causing the engine to smoke at startup.

After doing some research on here and the net it seems as if this is a relatively common issue yet I haven't seen anyone come back with a definitive cause.

As of last night I replaced the pcv valve again and put a qt of marvel mystery oil in the crankcase. After doing my research I found that some people say a excessive amount of sludge could possibly cause the crankcase pressure to be high forcing the oil where is shouldnt be.

Going to run the marvel mystery oil in there for another week and a half and then tear down the top end and pull the passenger valve cover to do a inspection to see how clean the motor is. Allthough we've had the truck for 4 years who knows what the PO's maintenece was like.

After the inpspection I'm going to clean up the intake, throttlebody, intake tube, MAF, change the plugs, wires and change the oil.

After that the next thing would be a leak down test and compression to see if its is blowby or a bad valve seal.
But the real question is if it were how would its get all the way up the intake tube?

ughhh

Also the truck when we bought it from the used car dealer never had any vac lines attached to those hard lines on the manifold so no idea what they're for