STS Bulletin about oil blow by....LONG...
02-21-2006, 09:30 AM
#1
STS Bulletin about oil blow by....LONG...
Hot out of my e-mail this morning.
Engine Blow-by or Oil Leaking at Engine Troubleshooting
If you are experiencing oil leaking at the engine or blowing your dipstick out, you are getting excessive pressure inside the crank case. This can come from 2 different sources. First and worst could be broken rings/pistons (lets hope it isn't that). To test for piston/ring damage, Start the car and let it idle, then remove the vent hose from the passenger side valve cover (GM). Lightly cover the vent with your finger. You should actually have some suction on that valve cover vent. If it is puffing smoke out of the vent like a little steam engine, then you most likely have engine damage. A compression test and/or leak-down test would be the next step in diagnostics.
What you probably have though is the PCV system either not connected up right or not functioning correctly. Check the PCV switch valve against the instruction manual to make sure that the hoses are connected and routed properly. The valve cover vent hose should be connected to the single port side of the switch valve. The breather filter should be on the top port (furthest from metal body) on the dual port side of the switch valve. The T-Body hose should be on the lower port (nearest the metal body) on the dual port side of the switch valve.
The functionality of the PCV switch valve can be checked as follows:
Normal Operation (no 12 volt supply to switch valve during vacuum) - the single port (valve cover) is vented directly to the lower port (throttle body). This allows the metered throttle body air to be drawn into the crank case and through the PCV valve into the intake manifold for normal PCV valve operation.
Switched Operation (12 volt supplied to switch valve above 1 psi boost) - the single port (valve cover) is switched over and vented to the end port (breather filter). This allows any excess crank case gasses to be vented out through the breather filter to atmosphere. The lower port is closed off to prevent boost from blowing out of the throttle body. (Note: Carb kits do not use the breather filter and are vented through a hose on the end port back into the turbocharger inlet.)
The electrical system which operates the PCV switch valve is as follows:
The ground for the PCV switch valve is the metal body of the valve. The valve must be securely bolted to a good ground. (Note: On GM trucks, the PCV switch valve is bolted to the plastic intake manifold (non-grounded). The STS electrical harness is equipped with a BLACK ground wire that must be attached to the mounting bolt which secures the valve to the plastic intake manifold. This BLACK wire is the GROUND supply for the valve and is NOT the GROUND supply for the harness.)
The 1 psi pressure switch (not the pressure switch located on the oil pump inlet) should be located in the engine compartment (see installation manual). The RED wire should supply 12 volts to the pressure switch any time the engine is running. The BROWN (some models use a BLUE wire) wire on the opposite terminal of the pressure switch has 2 different connections. First is that it controls the secondary relay which will turn the oil pump onto high speed at 1 psi boost. Second is that it sends 12 volts to the PCV switch valve at 1 psi boost. With the engine running, jump the terminals on the 1 psi pressure switch. You should hear the oil pump go to high speed and you should be able to fell the PCV switch valve 'click' as it switches the port venting. (Note: Refer to electrical system tests in the back of the instruction manual)
If the PCV switch valve system is operating properly, then the boost is most likely blowing into the crank case through the factory PCV valve.
To check this, remove the rubber connector from the intake manifold behind the throttle body (on the passenger side) that connects the PCV valve to the intake manifold (GM LS1). Plug off the port on the intake manifold and leave the PCV valve open to atmosphere. You can check the flow by carefully attempting to blow air through the PCV valve into the crank case or just run the car and see if the problem goes away.
If the problem goes away with the PCV valve disconnected and the manifold capped, the PCV valve is letting boost pass through it into the crank case. (Note: Some newer GM vehicles use a PCV orifice (small hole) rather than an actual PCV valve. If the vehicle is equipped with a PCV orifice, an inline check valve must be installed to prevent boost from pressurizing the crank case. The GM 8.1L engines use this type of PCV system. Contact STS for a PCV check valve solution for the 8.1L or for universal PCV check valves.) Installing a new PCV valve may correct the problem; however, many aftermarket PCV valves don't offer a positive seal and allow air to flow past the valve under boost. Check the valve for a positive seal before installing it on the vehicle. The problem may be due to a buildup of carbon deposits inside the PCV hoses which contaminates the valve.
Installing a check valve inline between the PCV valve and the intake manifold that only allows flow from the valve into the manifold and not the reverse is a good solution, especially for high boost applications (over 5 psi). STS does have a check valve available that fits inside the factory rubber PCV connector at the intake manifold on LS1 style engines nicely. They are about $25 if you need one.
Talk to you later, Rick @ STS
www.STSTurbo.com
Engine Blow-by or Oil Leaking at Engine Troubleshooting
If you are experiencing oil leaking at the engine or blowing your dipstick out, you are getting excessive pressure inside the crank case. This can come from 2 different sources. First and worst could be broken rings/pistons (lets hope it isn't that). To test for piston/ring damage, Start the car and let it idle, then remove the vent hose from the passenger side valve cover (GM). Lightly cover the vent with your finger. You should actually have some suction on that valve cover vent. If it is puffing smoke out of the vent like a little steam engine, then you most likely have engine damage. A compression test and/or leak-down test would be the next step in diagnostics.
What you probably have though is the PCV system either not connected up right or not functioning correctly. Check the PCV switch valve against the instruction manual to make sure that the hoses are connected and routed properly. The valve cover vent hose should be connected to the single port side of the switch valve. The breather filter should be on the top port (furthest from metal body) on the dual port side of the switch valve. The T-Body hose should be on the lower port (nearest the metal body) on the dual port side of the switch valve.
The functionality of the PCV switch valve can be checked as follows:
Normal Operation (no 12 volt supply to switch valve during vacuum) - the single port (valve cover) is vented directly to the lower port (throttle body). This allows the metered throttle body air to be drawn into the crank case and through the PCV valve into the intake manifold for normal PCV valve operation.
Switched Operation (12 volt supplied to switch valve above 1 psi boost) - the single port (valve cover) is switched over and vented to the end port (breather filter). This allows any excess crank case gasses to be vented out through the breather filter to atmosphere. The lower port is closed off to prevent boost from blowing out of the throttle body. (Note: Carb kits do not use the breather filter and are vented through a hose on the end port back into the turbocharger inlet.)
The electrical system which operates the PCV switch valve is as follows:
The ground for the PCV switch valve is the metal body of the valve. The valve must be securely bolted to a good ground. (Note: On GM trucks, the PCV switch valve is bolted to the plastic intake manifold (non-grounded). The STS electrical harness is equipped with a BLACK ground wire that must be attached to the mounting bolt which secures the valve to the plastic intake manifold. This BLACK wire is the GROUND supply for the valve and is NOT the GROUND supply for the harness.)
The 1 psi pressure switch (not the pressure switch located on the oil pump inlet) should be located in the engine compartment (see installation manual). The RED wire should supply 12 volts to the pressure switch any time the engine is running. The BROWN (some models use a BLUE wire) wire on the opposite terminal of the pressure switch has 2 different connections. First is that it controls the secondary relay which will turn the oil pump onto high speed at 1 psi boost. Second is that it sends 12 volts to the PCV switch valve at 1 psi boost. With the engine running, jump the terminals on the 1 psi pressure switch. You should hear the oil pump go to high speed and you should be able to fell the PCV switch valve 'click' as it switches the port venting. (Note: Refer to electrical system tests in the back of the instruction manual)
If the PCV switch valve system is operating properly, then the boost is most likely blowing into the crank case through the factory PCV valve.
To check this, remove the rubber connector from the intake manifold behind the throttle body (on the passenger side) that connects the PCV valve to the intake manifold (GM LS1). Plug off the port on the intake manifold and leave the PCV valve open to atmosphere. You can check the flow by carefully attempting to blow air through the PCV valve into the crank case or just run the car and see if the problem goes away.
If the problem goes away with the PCV valve disconnected and the manifold capped, the PCV valve is letting boost pass through it into the crank case. (Note: Some newer GM vehicles use a PCV orifice (small hole) rather than an actual PCV valve. If the vehicle is equipped with a PCV orifice, an inline check valve must be installed to prevent boost from pressurizing the crank case. The GM 8.1L engines use this type of PCV system. Contact STS for a PCV check valve solution for the 8.1L or for universal PCV check valves.) Installing a new PCV valve may correct the problem; however, many aftermarket PCV valves don't offer a positive seal and allow air to flow past the valve under boost. Check the valve for a positive seal before installing it on the vehicle. The problem may be due to a buildup of carbon deposits inside the PCV hoses which contaminates the valve.
Installing a check valve inline between the PCV valve and the intake manifold that only allows flow from the valve into the manifold and not the reverse is a good solution, especially for high boost applications (over 5 psi). STS does have a check valve available that fits inside the factory rubber PCV connector at the intake manifold on LS1 style engines nicely. They are about $25 if you need one.
Talk to you later, Rick @ STS
www.STSTurbo.com
02-21-2006, 11:23 AM
#2
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Wow, very interesting. Thanks for posting that up. I think I'm going to go ahead with my check ball valve idea. But I'll be checking my PCV valve first. I honestly don't think that little solenoid valve can flow enough to vent +10psi from my crankcase. Whatever, they should fix this **** for free.
02-21-2006, 12:11 PM
#3
Originally Posted by vanillagorilla
Wow, very interesting. Thanks for posting that up. I think I'm going to go ahead with my check ball valve idea. But I'll be checking my PCV valve first. I honestly don't think that little solenoid valve can flow enough to vent +10psi from my crankcase. Whatever, they should fix this **** for free.
02-21-2006, 01:10 PM
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I think that the '03 and up have the fixed oriface PCV Valve. The 99-02 should have a check valve in the PCV Valve. I am not sure if that is sufficient to keep boost from pressurizing the crankcase or not. I guess I need an inline check valve in mine. This is the first that I have been told this even though I asked Adam (when he was there) and then Dave South about this. The other option is to disconnect the PCV system all together and let both sides vent to the atmosphere through some kind of filter and plug the connections at the manifold on the driver's side and after the Hoobs switch on the passenger side.
02-21-2006, 01:16 PM
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Originally Posted by onyx
#1 take that chuck norris crap outta your sig...
#2 make it so your truck doesnt blow oil all over my rig again.
#2 make it so your truck doesnt blow oil all over my rig again.
#1.) www.chucknorrisfacts.com
#2.) Consider your truck lucky to have been peppered by valvoline.
Anyway, I might aswell take my PCV off. I mean I don't have cats so it's no like I'd be breaking any laws.
I'm pretty sure I don't have a check valve on my PCV, and its a '00.
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02-21-2006, 02:04 PM
#8
This is the new and old on my 02 truck.
No check valve here. So will it work better with or without the check valve, all this crap is making me second guess myself.
If my crankcase has positive pressure in it would it not be best to let it bleed off and when its vacumn let it stay that way by way of the check valve closing???? I'm thinking it needs the check valve no????
https://www.performancetrucks.net/fo...d.php?t=359584
No check valve here. So will it work better with or without the check valve, all this crap is making me second guess myself.
If my crankcase has positive pressure in it would it not be best to let it bleed off and when its vacumn let it stay that way by way of the check valve closing???? I'm thinking it needs the check valve no????
https://www.performancetrucks.net/fo...d.php?t=359584
02-21-2006, 02:53 PM
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As long as your crankcase can vent then it will be fine. I am not sure if it works better just venting to the atmosphere or if it works better with the closed loop system venting through the intake manifold. I have seen arguements that the factory closed loop PCV system does a better job of removing moisture from the crankcase because it creates a flow of air through the crankcase rather than just venting excess crankcase pressure.
If you put an inline check valve in the line to the PCV valve and let the factory PCV ststem work as intended then that may be the best solution. At the very least it should pass emmissions that way.
If you vent it to the atmosphere and leave the Hoobs switch to turn your oil pump to high when you are under boost you do not have to worry about the STS solenoid venting to the atmosphere or about boost pressure getting into the crankcase.
Advantages either way I guess.
If you put an inline check valve in the line to the PCV valve and let the factory PCV ststem work as intended then that may be the best solution. At the very least it should pass emmissions that way.
If you vent it to the atmosphere and leave the Hoobs switch to turn your oil pump to high when you are under boost you do not have to worry about the STS solenoid venting to the atmosphere or about boost pressure getting into the crankcase.
Advantages either way I guess.
02-21-2006, 03:47 PM
#10
Originally Posted by Mort
As long as your crankcase can vent then it will be fine. I am not sure if it works better just venting to the atmosphere or if it works better with the closed loop system venting through the intake manifold. I have seen arguements that the factory closed loop PCV system does a better job of removing moisture from the crankcase because it creates a flow of air through the crankcase rather than just venting excess crankcase pressure.
If you put an inline check valve in the line to the PCV valve and let the factory PCV ststem work as intended then that may be the best solution. At the very least it should pass emmissions that way.
If you vent it to the atmosphere and leave the Hoobs switch to turn your oil pump to high when you are under boost you do not have to worry about the STS solenoid venting to the atmosphere or about boost pressure getting into the crankcase.
Advantages either way I guess.
If you put an inline check valve in the line to the PCV valve and let the factory PCV ststem work as intended then that may be the best solution. At the very least it should pass emmissions that way.
If you vent it to the atmosphere and leave the Hoobs switch to turn your oil pump to high when you are under boost you do not have to worry about the STS solenoid venting to the atmosphere or about boost pressure getting into the crankcase.
Advantages either way I guess.
The other thing is, when using vent filters you will smell the esense of hot oil when the vent filter/breather has oil on it. My truck already smells like a refinery with the cats chopped off, I don't need to give Johhny Law any reasons to start poking around when I get pulled over.
The thing that still bugs me is why am I getting so much positive pressure in my crankcase? Enough to push oil out and up the dipstick and also out the STS control valve filter??? Disturbing, I'm waiting to blow crank seal or something worse. I did see a slight loss of vacumn over the last couple of months, I wonder if I have any real issue about to rear their ugly heads???