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05 c6 ls2 I’m getting oil in the intake and on the plugs, it has a catch can coming off the valley cover and the driver cover has this cap. Any purpose for the cap? I’m trying to figure out my oil issue and went to check pcv system and ran across this
Last edited by eisworthr; Oct 25, 2022 at 10:18 PM.
im still getting a good bit of oil in the intake, looks to be going through the valve cover hose at higher rpms. Oil pressure seems a little high constant 60-80, could this be caused by a closed catch can possibly? I have a catch can but it is closed im wondering a vented can would correct this?
oil out the vent side is usually either high oil flow, high blow-by (hopefully caused by high hp), or both. sometimes also unusually high suction from an undersized or clogged air filter
our can systems take the load off of the factory vent strategy with our auxiliary pressure release, so that part would be resolved www.mightymousesolutions.com
Have you checked/emptied the vent can?
Disclaimer: not emission compliant. Get a real vent can, plumb and -10 hose from each rocker cover to the can and block off the ports on the valley cover and intake manifold. If it is a dry sump engine, add a drain hose from the can to the tank.
Have you checked/emptied the vent can?
Disclaimer: not emission compliant. Get a real vent can, plumb and -10 hose from each rocker cover to the can and block off the ports on the valley cover and intake manifold. If it is a dry sump engine, add a drain hose from the can to the tank.
I have checked and emptied the can, my cans not vented and has a valve in it. My thinking was maybe that unvented can is making more pressure in the crankcase pushing the oil back through the valve cover possibly
I have checked and emptied the can, my cans not vented and has a valve in it
What kind of valve are you talking about? If your talking about a check valve, In a non-boosted engine such as yours, you don't need a check valve in your PCV system. Remove it from the catch can.
The inlet to the catch can should be marked as well as the exit. The catch can inlet will be routed via hose to the valley cover vent and the catch can outlet will be routed via hose to the vacuum port on the front of the intake manifold.
Additionally, a hose will be routed from the passenger side valve cover to the rubber hose (bellows) just in front of the throttle body. This hoses purpose is to allow fresh filtered air into the crankcase in order to replace the dirty crankcase fumes that are sent through the catch can, cleaned of oil and then sucked into the intake manifold.
Here is a simple routing of the hoses to complete the system:
Notice the cap on the driver's side valve cover.
Last edited by Turbo6TA; Oct 30, 2022 at 06:52 PM.
What kind of valve are you talking about? If your talking about a check valve, In a non-boosted engine such as yours, you don't need a check valve in your PCV system. Remove it from the catch can.
The inlet to the catch can should be marked as well as the exit. The catch can inlet will be routed via hose to the valley cover vent and the catch can outlet will be routed via hose to the vacuum port on the front of the intake manifold.
Additionally, a hose will be routed from the passenger side valve cover to the rubber hose (bellows) just in front of the throttle body. This hoses purpose is to allow fresh filtered air into the crankcase in order to replace the dirty crankcase fumes that are sent through the catch can, cleaned of oil and then sucked into the intake manifold.
Here is a simple routing of the hoses to complete the system:
Notice the cap on the driver's side valve cover.
Im assuming it has a check valve in it, i first flipped the lines wondering if the previous owner had the lines backwards since the can isnt marked, when i did that it was making a crazy noise like a cartoon ufo taking off. My lines are routed like the diagram but getting oil in the intake manifold and found oil on the hose from the valve cover to the intake tube
It takes energy to push fluid through hoses.
If you added a bunch of hoses and a can, now the crankcase pressure will be higher and more oil will flow out of the engine.
High crankcase pressure causes oil leaks and increases blow-by, it will decrease piston ring function. High crankcase pressure is high gas density which increases large oil droplet formation and oil suspended in PCV gas.
I recommend three things
1. Remove all the can and excess lines to reduce PCV friction so the gas can remain high velocity and return rapidly to the intake manifold. This will improve crankcase pressure, lowering it. Reinstall factory OEM pcv.
2. Perform a pressure test to determine whether the PCV and intake system is setup properly. If the PCV valve is poor quality or leaking it will interfere with crankcase pressure scavenging. This is very easy to do on natural aspirated engines, here is how we do for forced induction to show big picture.
3. Measure the crankcase pressure to make sure it remains below atmospheric at all times. High crankcase pressure is caused usually by:
1. Poor condition piston rings due to being run with high crankcase pressure for prolonged periods
2. Broken piston rings or broken pistons causing leaking combustion to crankcase
3. Wrong air filter flow rate at pressure drop given engine flow rate, for example 500CFM @ 1.5" Hg for an engine that can flow 500CFM will produce 1.5" Hg pressure drop to the crankcase at peak power. If the air filter is too large, it will not provide proper pressure drop at WOT and oil will blow out of the engine.
Here is an example how I measure crankcase pressure
That engine has almost 250,000 miles, 600rwhp, Daily Driver, 20psi of boost pressure. Because the PCV has been measured and set properly, there is no oil blowing out of the engine, no oil droplet formation, reduced windage due to dropping crankcase gas density. Increased oil scavenging to the oil pan at WOT and oil wicked from engine parts. Increased oil lifespan despite forced induction and turbocharger rich air/fuel ratios. The piston rings are clean and free from carbon conglomerates because low pressure prevents early ring switching and ring flutter.
If you vent the crankcase it will increase engine wear, and lead to eventual failure, you will lose all benefits of PCV. Venting is not PCV, Venting is 80's technology before people understood PCV well. https://www.theturboforums.com/info/...rs-101.378656/
So you would never want to use a can with a breather on it, as that is breaking the evacuation cycle leaving the contaminants in the crankcase, and also allows pressure to build and be pushed out which is never proper. That technology went out with the 1980's.
No, you do not want small hoses, small hoses increase the velocity of the oil/air exiting the engine. When I do a real dry sump Corvette. I use a -10 hose on each rocker cover and a -16 for the tank vent and plug the ports on the valley cover and intake. This way, no oil at can enter the intake tract. Kind of limited to -8 hoses on a production "dry" sump system. When the engine is running a speed, on the track, the fresh air line now becomes a source to dump oil into the intake. I've yet to blow up an engine with the setup I use and I've built hundreds of track Corvettes.
No, you do not want small hoses, small hoses increase the velocity of the oil/air exiting the engine. When I do a real dry sump Corvette. I use a -10 hose on each rocker cover and a -16 for the tank vent and plug the ports on the valley cover and intake. This way, no oil at can enter the intake tract. Kind of limited to -8 hoses on a production "dry" sump system. When the engine is running a speed, on the track, the fresh air line now becomes a source to dump oil into the intake. I've yet to blow up an engine with the setup I use and I've built hundreds of track Corvettes.
Completely different topic. With a dry sump system there is no need to maintain minimum kinetic energy and organization within PCV tubes as that energy is provided by the dry sump pump. Same with a vacuum pump- it adds kinetic energy and fluid can gain necessary momentum and velocity vector for organized flow. If we enlarge the tubes they can maintain internal energy and organization thanks to aux pumping energy input.
The opposite is true in wet sump applications where kinetic energy is supplied via pressure drop of the air filter at wide open throttle. In that case the kinetic energy supply is low and it will be difficult to maintain organization if tubes become larger, the gas will disorganize.
Even with a dry sump, the crankcase pressure must be measured. Blow-by is not a constant. Some pumping effort equates to some resultant pressure drop. If the pressure cannot be maintained then something must be done- increased pumping energy or a re-configure of the hoses, shorter hoses for example.
The act of installing a breathing can on a dry sump system is not an option which is why I bother to mention these and recommend return to OEM pcv system for wet sump.
Pcv system with catch can
