Oil in intake... no PCV setup either
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From: St.Louis, Missouri
Oil in intake... no PCV setup either Well I had this common issue on my old 346... oil in my LS6 intake due to the stock PCV system. I decided to address the issue on my new 402 and delete the PCV system and just run a breather on each valve cover. I noticed what appeared to be a small oil leak under the car and after tracing it up the bellhousing and block I decided to remove the FAST 90 intake to see where it was coming from. It appeared to maybe be coming from the oil pressure sending unit. After removing the intake I opened the TB blades and noticed oil in my intake once again. WTF were my initial thoughts. No PCV system and no breather tube from the valve cover to the intake... basically no chance for oil to get in the intake. At this point the only thing I can think of is that oil is leaking down my rocker bolt holes into the intake port and then vacuum is drawing that oil into the intake while some intake valves are closed and others are open taking in the intake charge. Does this make sense? Possible? Anyone else? I always thought you would just burn oil if you didn't seal those bolts up well but I guess you could draw it back into the intake as well. I believe I used liquid teflon or pipe sealer or whatever when I put them in... apparently it didn't hardened or it broke down. What should I use to seal these rocker bolts? Could anything else be causing this oil in my intake?
Thanks!!
-Jeremy
*sorry for the novel
Thanks!!
-Jeremy
*sorry for the novel
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I just ran into this problem with a 408 that I rebuilt for a customer. It was getting enough up there that is was smoking. We did everything we could think of to stop the smoking. Finally found that most of the intake ports were cracked and allowing oil to run down into the intake ports. When the rockers are torque down it would open the cracks, when you took them off you could see nothing wrong.
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Originally Posted by willyfastz
Yeah I dought thats your problem but I didn't think it was my problem eighter. Just giving you something that can happen so you can look for that if you can't find anything else.
I have the same issue with mine at the moment. Cnc'd ls6 heads. Jeremy I have seen this problem several times here lately. Not causing any smoke but if you look in the intake you can see it. Do you have that vent tube connected that runs from the front p-side valve cover to the throttle body? If so I installed a catch can for the oil between the valve cover and the throttle body.
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Originally Posted by brokeTA
I have the same issue with mine at the moment. Cnc'd ls6 heads. Jeremy I have seen this problem several times here lately. Not causing any smoke but if you look in the intake you can see it. Do you have that vent tube connected that runs from the front p-side valve cover to the throttle body? If so I installed a catch can for the oil between the valve cover and the throttle body.
So just in case i just recieved my LS6 valley cover and im ready to plug my PCV system completely 
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From: St.Louis, Missouri
Originally Posted by brokeTA
I have the same issue with mine at the moment. Cnc'd ls6 heads. Jeremy I have seen this problem several times here lately. Not causing any smoke but if you look in the intake you can see it. Do you have that vent tube connected that runs from the front p-side valve cover to the throttle body? If so I installed a catch can for the oil between the valve cover and the throttle body.
Yah I use teflon sealer on mine. The catch can seemed to help a little but def. didn't eliminate the problem. It has to be something like you said Jeremy because I have pulled plugs to verify any unknown engine problems, and the plugs look great.
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Originally Posted by GTA91
Well I had this common issue on my old 346... oil in my LS6 intake due to the stock PCV system. I decided to address the issue on my new 402 and delete the PCV system and just run a breather on each valve cover. I noticed what appeared to be a small oil leak under the car and after tracing it up the bellhousing and block I decided to remove the FAST 90 intake to see where it was coming from. It appeared to maybe be coming from the oil pressure sending unit. After removing the intake I opened the TB blades and noticed oil in my intake once again. WTF were my initial thoughts. No PCV system and no breather tube from the valve cover to the intake... basically no chance for oil to get in the intake. At this point the only thing I can think of is that oil is leaking down my rocker bolt holes into the intake port and then vacuum is drawing that oil into the intake while some intake valves are closed and others are open taking in the intake charge. Does this make sense? Possible? Anyone else? I always thought you would just burn oil if you didn't seal those bolts up well but I guess you could draw it back into the intake as well. I believe I used liquid teflon or pipe sealer or whatever when I put them in... apparently it didn't hardened or it broke down. What should I use to seal these rocker bolts? Could anything else be causing this oil in my intake?
Thanks!!
-Jeremy
*sorry for the novel
Thanks!!
-Jeremy
*sorry for the novel
mine does same thing too, but with my intake off lookes a lot worse than yours, mine only smokes when driveing it real hard, but i think mine is ring blow by since i got 165,xxx miles o nthe bottom end
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From: St.Louis, Missouri
Originally Posted by ls1408cp
reversion I have the same problem
Nice ETs at KC by the way... you going in March? I might be sending you a PM.
https://ls1tech.com/forums/showthrea...ight=reversion
I think the car did alright for its shake down passes. It will go nines in march on motor easy.
I think the car did alright for its shake down passes. It will go nines in march on motor easy.