Oil pooled in the intake duct

[mgroeger]

Yesterday, while putting on a winch, I removed the intake box to run the wires under it. While I had the box off I noticed a shiny spot about 2" inside the rubber intake connector boot.
I rubbed it with my finger and discovered it was dark thick oil, about a teaspoon or so worth that had puddled by the inner lip of the rubber boot.
I've owned many many cars and not once have I ever encountered this.

I am wondering the following:
Is there a problem with the PCV system?
Am I getting some sort of blow back from the valve cover hose? (I think there is one that connects the rubber duct to the valve cover)
Is it because the oil is so freaking viscous that it blows around?

It's real easy to check your own, simply loosen the clamp and pop the boot or take off the intake box cover and pull it out of the boot. If anyone would be so inclined I would greatly appreciate it.

One thing to note, I do like to get heavy on the gas. I will jump on it and run the engine up through the RPM range. Nothing abusive but let's say spirited.

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[mgroeger]

Ughhh... no one else has this problem or checked yet?

 

[WrongWheelDrive]

intake tracks have oil in them I wouldnt worry about it, they make oil catch cans to remove it if you wanted to. Usually they are used on performance cars or boosted setups

 

[mgroeger]

OK, thanks. I have never seen this on any vehicle I have owned so it caught me off guard a little. Had already thought of a catch can as well. Thanks for the info.

 

[spurly]

I assume today's emission regulations are why you may not be used to seeing it in older vehicles. On old vehicles the PCV usually just vented to the atmosphere. But now, there's a line or two from the head and block connecting to the intake. I have a catch can on my 2016 Silverado and I am honestly surprised how much it catches. Not just oil, but fuel and moisture as well. I have 25k miles on the truck and the can has caught about a quart of filth that it has collected. I like to dump it in glass jars to see exactly what has been caught. Is it necessary to have one on a Wrangler or Silverado? No, but there's a reason boosted cars run them so it probably can't hurt on a N/A car. If anything, it should prolong the service interval for the manufacturers suggested 'intake cleaning' because of carbon build up. My $0.02 anyways.

 

[mgroeger]

Thanks for the input. I'm referring to a 2005 Toyota Highlander and 2008 Accord coupe in terms of the cars that I've never seen it in. They both had a hose from the intake manifold to the PCV located in the valve cover and a hose from the intake boot to the valve cover. That keeps air flowing through there and any vapor gets sucked back into the intake manifold and burned. Intake boot is pushing air into the valve cover intake manifold is sucking it out through the PCV
I too have put a catch can on my Highlander between the PCV and the intake manifold and I am amazed at how much it catches.
It is my understanding that the way the system works is that hose that connects from the intake boot to the valve cover has air being pushed through it from the natural aspiration of the engine drawing air into the boot. So I'm trying to understand how a system that uses PCV and has a hose pushing air into the valve cover is allowing oil mist to come back out of that valve cover hose into the intake boot. It doesn't make any sense.
It's also my understanding the a catch can goes between the PCV and the intake manifold to "catch" the oil mist/vapor and keep it from going into the intake manifold. This would have nothing to do with the intake boot but I need to double check how it is setup on the Jeep.

 

[redelses]

I just saw your post now - mine is in for the second time with this issue of the oil pooling in the air intake duct. They initially told me that it happen when the oil is filled too quickly at an oil change. But it has pooled up again since the last time it was cleaned out and without another oil change. We'll see what they say after today's appt.

Thanks for the input. I'm referring to a 2005 Toyota Highlander and 2008 Accord coupe in terms of the cars that I've never seen it in. They both had a hose from the intake manifold to the PCV located in the valve cover and a hose from the intake boot to the valve cover. That keeps air flowing through there and any vapor gets sucked back into the intake manifold and burned. Intake boot is pushing air into the valve cover intake manifold is sucking it out through the PCV
I too have put a catch can on my Highlander between the PCV and the intake manifold and I am amazed at how much it catches.
It is my understanding that the way the system works is that hose that connects from the intake boot to the valve cover has air being pushed through it from the natural aspiration of the engine drawing air into the boot. So I'm trying to understand how a system that uses PCV and has a hose pushing air into the valve cover is allowing oil mist to come back out of that valve cover hose into the intake boot. It doesn't make any sense.
It's also my understanding the a catch can goes between the PCV and the intake manifold to "catch" the oil mist/vapor and keep it from going into the intake manifold. This would have nothing to do with the intake boot but I need to double check how it is setup on the Jeep.

 

[mgroeger]

I just saw your post now - mine is in for the second time with this issue of the oil pooling in the air intake duct. They initially told me that it happen when the oil is filled too quickly at an oil change. But it has pooled up again since the last time it was cleaned out and without another oil change. We'll see what they say after today's appt.

ROTFLMAO!!! "Oil filled too quickly" wow I am seriously blown away at the stupidity of some dealers. That by far is one of the dumbest things I have ever heard. That would mean that while pouring the oil into the valve cover through a 2" hole/tube that the oil came out of that bottle or filler hose sooooo fast that it filled the space under the valve cover completely and the oil pushed out of the breather tube all the way up into the intake hose.
Seriously that is the dumbest thing I have ever heard.
I would run away as far and fast from that dealership as I could, I'm not joking.
Here's your answer that I figured out and the dealer service manager confirmed as well as a fellow JL Jeeper. It is normal and I used to see it on much older cars where the oil would spit onto the filter and not so much in the intake tube. There is oil vapor under the valve cover and the system, via the PCV, is designed to suck out that oil and put it through the intake system along with the incoming air. Some, like my LJ, pull it right through the manifold while others suck it in through the intake; that's my understanding anyway. Regardless whether it's happening that way or if this is simply blow back it is normal but IMO not ideal and a catch can will eliminate this from happening.
As of now I've chose to do nothing with it but may throw a catch can on some day.
If it becomes really excessive (which it shouldn't) maybe you've got a bad PCV or some sort of obstruction but a little bit is normal and a catch can really does work at capturing it.
If you absolutely must go to this dealership be leery, also make sure they are only putting 5qts in and NOT 6qts as many dealerships seem to be doing. If they argue with you show them the owner's manual and make them put in 5 qts. THe oil should be right at the top of the hash marks if done properly. Also make sure they are doing a real oil drain and not sticking a suction hose down the dipstick tube.

 

[mgroeger]

I just saw your post now - mine is in for the second time with this issue of the oil pooling in the air intake duct. They initially told me that it happen when the oil is filled too quickly at an oil change. But it has pooled up again since the last time it was cleaned out and without another oil change. We'll see what they say after today's appt.

BTW, where in Utah do you live? We were out in Moab and Ouray CO and fell in love with Moab and are looking to move out there.

 

[redelses]

Yeah I am not super impressed with the dealer yet, but it's the only one here and I am making sure to bring it there to document everything.
They also put in 6 qts every time, and I just go home and drain 1 qt afterwards - no matter how many times I tell them the new engine only needs 5 qts, they are on autopilot...
I am thinking a catch can eventually, but will leave it for now.

I am out in St George area - which is southern Utah but about 5 hours from the Moab area (Salt Lake is only 4 hours from Moab, strangely enough, because they have a direct route whereas we have to circle or drive through the Colorado River). There's still lot of areas to explore around here, with some serious wheeling, but mostly empty deserted desert roads.

ROTFLMAO!!! "Oil filled too quickly" wow I am seriously blown away at the stupidity of some dealers. That by far is one of the dumbest things I have ever heard. That would mean that while pouring the oil into the valve cover through a 2" hole/tube that the oil came out of that bottle or filler hose sooooo fast that it filled the space under the valve cover completely and the oil pushed out of the breather tube all the way up into the intake hose.
Seriously that is the dumbest thing I have ever heard.
I would run away as far and fast from that dealership as I could, I'm not joking.
Here's your answer that I figured out and the dealer service manager confirmed as well as a fellow JL Jeeper. It is normal and I used to see it on much older cars where the oil would spit onto the filter and not so much in the intake tube. There is oil vapor under the valve cover and the system, via the PCV, is designed to suck out that oil and put it through the intake system along with the incoming air. Some, like my LJ, pull it right through the manifold while others suck it in through the intake; that's my understanding anyway. Regardless whether it's happening that way or if this is simply blow back it is normal but IMO not ideal and a catch can will eliminate this from happening.
As of now I've chose to do nothing with it but may throw a catch can on some day.
If it becomes really excessive (which it shouldn't) maybe you've got a bad PCV or some sort of obstruction but a little bit is normal and a catch can really does work at capturing it.
If you absolutely must go to this dealership be leery, also make sure they are only putting 5qts in and NOT 6qts as many dealerships seem to be doing. If they argue with you show them the owner's manual and make them put in 5 qts. THe oil should be right at the top of the hash marks if done properly. Also make sure they are doing a real oil drain and not sticking a suction hose down the dipstick tube.

 

[mgroeger]

Yeah I am not super impressed with the dealer yet, but it's the only one here and I am making sure to bring it there to document everything.
They also put in 6 qts every time, and I just go home and drain 1 qt afterwards - no matter how many times I tell them the new engine only needs 5 qts, they are on autopilot...
I am thinking a catch can eventually, but will leave it for now.

I am out in St George area - which is southern Utah but about 5 hours from the Moab area (Salt Lake is only 4 hours from Moab, strangely enough, because they have a direct route whereas we have to circle or drive through the Colorado River). There's still lot of areas to explore around here, with some serious wheeling, but mostly empty deserted desert roads.

Thanks for the info!
BTW... I'd make them drain it out there. Personally I just wouldn't want to drive with an extra qt. even if it's for a little bit. I'm OCD about stuff like that but I'm sure others will say it's no big deal

 

[ALRUI]

While doing an oil change yesterday we also replaced the air filter and I was letting my 15 year old take the cover off the air box. He wanted to remove the box lid so I un-fastened the clamp around the intake duct and he mentions there's oil inside the duct. I took a look and there was maybe 2 drops of oil in there total after 24K miles. I figure its nothing to worry about. Maybe I need to pour the oil in slower during oil changes

 

[mgroeger]

While doing an oil change yesterday we also replaced the air filter and I was letting my 15 year old take the cover off the air box. He wanted to remove the box lid so I un-fastened the clamp around the intake duct and he mentions there's oil inside the duct. I took a look and there was maybe 2 drops of oil in there total after 24K miles. I figure its nothing to worry about. Maybe I need to pour the oil in slower during oil changes

Please tell me you're making a joke about pouring the oil in slower

 

[ALRUI]

Please tell me you're making a joke about pouring the oil in slower

Yes, thats why the smiley face after the sentence. Maybe I should have put instead?

 

[mgroeger]

Yes, thats why the smiley face after the sentence. Maybe I should have put instead?

Whew, ok lol.
Have you run Uwharie yet? I see you are in Murphy NC.

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