GTA91

iTrader: (14)

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

marv

iTrader: (40)

<- is watching this thread...could be part of my problem as well.

TWISTEDTA

willyfastz

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.

GTA91

iTrader: (14)

I doubt mine are cracked... brand new stage 3 fully CNC'd 317 truck heads with 2.08 valves. I'll check for cracks though.

jub jub

Is it possible that with a little blow-by plus the any reversion you have that it is blowing back in at idle just before you shut it down.

GTA91

iTrader: (14)

Possible I guess... I'm not sure that I'm getting any blowby though.

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.

GTA91

iTrader: (14)

I appreciate it

TWISTEDTA

Here's an example of how bad mine is, look at the head ports...and thats my old motor too, but this new one is just as bad or worse.

GTA91

iTrader: (14)

Yeah, that's pretty much what mine looked like.

brokeTA

iTrader: (9)

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.

TWISTEDTA

I have to wait till monday to order mine, everyones out of stock at the moment. I have read several cases that the catch can doesnt help... So just in case i just recieved my LS6 valley cover and im ready to plug my PCV system completely

GTA91

iTrader: (14)

Andy, no vent tube from the valve cover to the intake. Its gotta be coming from the rocker bolts, I don't see any other way. Are you running breathers or a PCV/catch can setup? What do you use to seal the rocker bolts? I think Chad said he uses teflon thread sealer... I think the oil breaks it down though. I might try blue or red loctite this time.

brokeTA

iTrader: (9)

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.

ls1408cp

iTrader: (37)

reversion I have the same problem

Sean Collins

Dope up the intake port rocker bolts clean out the intake and report back. Could be a valve seal issue but it could also be a bolt leaking issue. seen it before.

silverZ98

iTrader: (6)

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

GTA91

iTrader: (14)

Care to expand on that?

Nice ETs at KC by the way... you going in March? I might be sending you a PM.

ls1408cp

iTrader: (37)

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.