Intake Oil Leak With Boost

[pearlnotchback]

I guess back about 6 months ago I replace my intake gasket on my notch because it was seeping antifreeze. No problems after no leaks etc. Added 6 lb Vortech and started blowing the pcv valve out. I removed the tube from the valve cover to the throttle body and problem solved. Now if I drive the car normal no hot rodding all is good but if I run it hard under boost and I mean hard as in no letting off until after 4th gear. I will see two small puddles of oil under the car the next day where it had blown out of the back of the intake and ran down to the floor. So do I need to pull the intake and attempt to re seal or could this be a vent problem allowing to much pressure and causing the oil to blow out? Oh and the pcv valve is still hooked up to the upper intake. If I need to change this how do I change it? What is everyones thoughts here?

 

[88LX5.Oh]

All engines will build up crank case pressure if they don't have a proper positive crank case ventilation system. Also there's always going to be a little blow-by no matter what (that's why PCV systems were created). Whether it be from the openings in the rings or just from little imperfections in the cylinder wall. But under boost is when you'll see the most blow-by of course. Your PCV valve may be slightly clogged with oil causing it to pop out after a certain PSI of pressure is built up. .

But I really am no engine expert.

PCV valve should just pull right out IIRC. And new ones are maybe like $5 at a parts store.

 

[pearlnotchback]

All engines will build up crank case pressure if they don't have a proper positive crank case ventilation system. Also there's always going to be a little blow-by no matter what (that's why PCV systems were created). Whether it be from the openings in the rings or just from little imperfections in the cylinder wall. But under boost is when you'll see the most blow-by of course. Your PCV valve may be slightly clogged with oil causing it to pop out after a certain PSI of pressure is built up. .

But I really am no engine expert.

PCV valve should just pull right out IIRC. And new ones are maybe like $5 at a parts store.

Ya I tried that all ready. The pcv valve and grommet are new.

 

[88LX5.Oh]

Ya I tried that all ready. The pcv valve and grommet are new.

Well have you verified that the rubber line and the port on the intake are not clogged?

 

[pearlnotchback]

No I havent had a chance to check it yet

 

[mob]

How did you remove the tube from the t/b to the v/c? That allows a small amount of air into the engine to circulate, the reason you blow out the PCV valve is because with the super charger you're are now boosting the crankcase through that tube and it needs to get out somewhere. If you just capped off the tube the engine is probably trying to grab air through the next weakest place, probably your oldest gasket like oil pan or rear main seal. Your best bet is putting the throttle body tube back on and venting the PCV valve into the air with a filter on it or something of that nature.

 

[srtthis]

by any chance did you put a breather on the valve cover?

 

[Bullitt95]

All engines will build up crank case pressure if they don't have a proper positive crank case ventilation system. Also there's always going to be a little blow-by no matter what (that's why PCV systems were created). Whether it be from the openings in the rings or just from little imperfections in the cylinder wall. But under boost is when you'll see the most blow-by of course.

Yes indeed. The best thing you can do to the crankcase ventilation system on a forced induction engine is to isolate it from the intake system altogether so that you don't have pressurized air being forced into the crankcase. That means removing the hose connecting the throttle body to the valve cover and capping the nipple on the TB. It's probably also adviseable to remove the PCV valve together with the vacuum hoses to the intake manifold and cap off both vacuum nipples.
There are two fixes to do:

1. Run a hose from the valve cover breather to one side of an oil catch can with a breather filter attached to the other side.

2. Insert a 3/4" 90 degree elbow fitting in the PCV grommet and run a hose from there to a second catch can with a breather filter.

This crankcase ventilation set-up will allow the crankcase to draw in filtered fresh air when it's under vacuum and when it's under positive pressure, blow out waste gases into the catch cans where the oil will be separated and only air will come out of the breather filters, and not leave an oily mess in the engine bay.

 

[Noobz347]

Yes indeed. The best thing you can do to the crankcase ventilation system on a forced induction engine is to isolate it from the intake system altogether so that you don't have pressurized air being forced into the crankcase. That means removing the hose connecting the throttle body to the valve cover and capping the nipple on the TB. It's probably also adviseable to remove the PCV valve together with the vacuum hoses to the intake manifold and cap off both vacuum nipples.
There are two fixes to do:

1. Run a hose from the valve cover breather to one side of an oil catch can with a breather filter attached to the other side.

2. Insert a 3/4" 90 degree elbow fitting in the PCV grommet and run a hose from there to a second catch can with a breather filter.

This crankcase ventilation set-up will allow the crankcase to draw in filtered fresh air when it's under vacuum, blow out waste gases into the catch cans where the oil will be separated and only air will come out of the breather filters, and not leave an oily mess in the engine bay.

Disagree, although this is an option is done more often than not.

The BEST thing that you can do is keep the PCV system intact. It's there for a reason. I causes the caustic gases suspended in the crank case to be burnt vs. being absorbed into the oil and/or providing an acidic film that coats all of your internal components (including bearings). What's more, when the oil is heated to operating temperature, it allows the water vapor to be removed form the engine vs. being abosrbed (again) by motor oil.

Were it me, I would reroute the hose from the throttle body to a point in the induction system up-stream of the supercharger (near the blower inlet). If your cank case pressure is really excessive or you don't have baffles installed at the filler neck then a small air/oil seprator will clean it up. Additionally, I would punch a grommet sized hole in the driver side valve cover and run that pre-metered air back into the intake tract through a brake booster, one way valve (you can find these in the HELP section of your favorite auto parts store).

This method keeps your crank case ventilation system intact and also keeps the engine combo from taking in or expelling metered air.

 

[srtthis]

Disagree, although this is an option is done more often than not.

The BEST thing that you can do is keep the PCV system intact. It's there for a reason. I causes the caustic gases suspended in the crank case to be burnt vs. being absorbed into the oil and/or providing an acidic film that coats all of your internal components (including bearings). What's more, when the oil is heated to operating temperature, it allows the water vapor to be removed form the engine vs. being abosrbed (again) by motor oil.

Were it me, I would reroute the hose from the throttle body to a point in the induction system up-stream of the supercharger (near the blower inlet). If your cank case pressure is really excessive or you don't have baffles installed at the filler neck then a small air/oil seprator will clean it up. Additionally, I would punch a grommet sized hole in the driver side valve cover and run that pre-metered air back into the intake tract through a brake booster, one way valve (you can find these in the HELP section of your favorite auto parts store).

This method keeps your crank case ventilation system intact and also keeps the engine combo from taking in or expelling metered air.

i agree with the other guy... keeping oil out of the intake track is huge on a power adder car. oil burns REALLY hot and REALLY fast. which is really bad with a power adder, we have burnt up a lot of pistons from getting oil past the rings. allowing it in the intake track is just asking for it get into the chambers. same reason i dont run a PCV on my car. i want to throw as much timing to my car as i can and having any oil in the intake track will cause it to knock before i want it to.

 

[Noobz347]

i agree with the other guy... keeping oil out of the intake track is huge on a power adder car. oil burns REALLY hot and REALLY fast. which is really bad with a power adder, we have burnt up a lot of pistons from getting oil past the rings. allowing it in the intake track is just asking for it get into the chambers. same reason i dont run a PCV on my car. i want to throw as much timing to my car as i can and having any oil in the intake track will cause it to knock before i want it to.

If a PCV system is inadequate of done improperly, then bad things can happen. Same applies to any other portion of an engine combination. In addition, there's a HUGE difference between the kinds of things necessary for a race car vs. one that is regularly driven on the street.

I run a lot of boost for a street car. More than I need for sure. LOL It took me some time and trial and error to get teh PCV system up to the task. The final product is very similar to what I described above. I run two oil separators. One between the oil filler neck and the TB (I rarely ever see oil in it at all) and one between the Vac lines and the PCV valve for evacuating crank case pressure. When I've spent a significant amount of time in boos then I DO see some oil in that separator.

Edit: Oh... and there's a HUGE difference in how the oil looks at change time as a result.

 

[RacEoHolic330]

Noobz... How much boost are you running?

 

[Noobz347]

Noobz... How much boost are you running?

13-15 lbs depending on ambient air.

 

[srtthis]

If a PCV system is inadequate of done improperly, then bad things can happen. Same applies to any other portion of an engine combination. In addition, there's a HUGE difference between the kinds of things necessary for a race car vs. one that is regularly driven on the street.

I run a lot of boost for a street car. More than I need for sure. LOL It took me some time and trial and error to get teh PCV system up to the task. The final product is very similar to what I described above. I run two oil separators. One between the oil filler neck and the TB (I rarely ever see oil in it at all) and one between the Vac lines and the PCV valve for evacuating crank case pressure. When I've spent a significant amount of time in boos then I DO see some oil in that separator.

Edit: Oh... and there's a HUGE difference in how the oil looks at change time as a result.

yea we run a vac pump and all to pull a vac and seat the rings pull oil off the crank and stuff like that. but im looking at doing a set up like yours also on my street car with an electric vac pump to do tha same thing. end result is the same but no oil in the intake.

 

[Noobz347]

yea we run a vac pump and all to pull a vac and seat the rings pull oil off the crank and stuff like that. but im looking at doing a set up like yours also on my street car with an electric vac pump to do tha same thing. end result is the same but no oil in the intake.

Do a build thread when you do it. I wouldn't mind seeing a setup like that so long as none of the accessories had to be sacrificed.

 

[srtthis]

i dont have on my motor but i will do one.

plan is a 90 off 1 VC then a T on the other with a straight holde barb off my PCV hole thats got a freeze plug in it. run both those lines together into a air oil sep. then to the electric vac pump off an LT1 car then to a catch can. just need to find a deal on a LT1 pump then i can start working on it. i have all the other stuff

 

[pearlnotchback]

How did you remove the tube from the t/b to the v/c? That allows a small amount of air into the engine to circulate, the reason you blow out the PCV valve is because with the super charger you're are now boosting the crankcase through that tube and it needs to get out somewhere. If you just capped off the tube the engine is probably trying to grab air through the next weakest place, probably your oldest gasket like oil pan or rear main seal. Your best bet is putting the throttle body tube back on and venting the PCV valve into the air with a filter on it or something of that nature.

The instructions that came with the supercharger said to remove the tube from the t/b and plud it off but run a hose from the valve cover to the air filter box that came with the vortech. If I run a filter on the pcv and vent it to the air do i just plug the port on the upper intake where the pcv hose connected?

 

[pearlnotchback]

by any chance did you put a breather on the valve cover?

No I havent. I thought about that do you think it will help?

 

[srtthis]

Yea... Def need a breather... Prob one on both valve covers if you can

 

[Bullitt347]

i dont have **** on my motor but i will do one.

plan is a 90 off 1 VC then a T on the other with a straight holde barb off my PCV hole thats got a freeze plug in it. run both those lines together into a air oil sep. then to the electric vac pump off an LT1 car then to a catch can. just need to find a deal on a LT1 pump then i can start working on it. i have all the other stuff

Napa sells the LT1 electric vacuum pump and it has a one year warranty on it, which for me came in handy as i had it to close to the engine in that the carankcase fumes were to hot and burned the electric pump up. Napa warrantied it no questions asked and I now have the electric vacuum pump mounted down in the front bumper cover, so that by the time the crankcase fumes get thru the oil separator and to the vacuum pump, there is no heat in the vapors that get to the pump. I also have a metered air bleed to allow for fresh air to come into the crankcase (at the old PCV location) and help replace the crankcase fumes. You really need a vacuum gauge on the crankcase so that you can change the metered air bleed so that at WOT you still have some vacuum in the crankcase. You will notice the highest vacuum readings at idle and cruise when "blowby" past the rings is the least as opposed to WOT where "blowby" is the highest.