Topic: Help! Oil shooting out VC PCV Tube at WOT!

[MattM]

So....As the title says...

SO I took off the valve cover to intake tube with the Check valve because it was clogged and then I vented to atmosphere. IT's been running perfectly for over two years.

So right after I get the car back for the rear diff and do some WOT pulls it now is shooting like a table spoon of oil out that tube when I do a WOT pull, and when I cleaned up the oil it smells somewhat like gas as well. I've attached a pic of the filter over that tube so you know where I'm talking about.

My car runs and drives great and this only happens at WOT. Does anyone have any idea why it would do this, or what I could do short of getting a new engine?

GOd I really hope this is somehting simple!! If not I'm torching this car!!!

I'd appreciate any help you guys can give me.

[DeepBlueGXP]

Any codes

[MattM]

Any codes

Nope...No codes whatsoever.  No hard starting issues, and no blue smoke out the exhaust.

[Uranium-238]

Dunno about the LNF, but oil out the PCV is normal on an LS, though not in the amounts you're talking about. But, the LNF is boosted, so who knows?

For me, step 1 would be to do a compression check. Make sure the oil isn't a sign of excess blow-by. Step 2 would be to get a catch can, plumb it in line, and go back to venting the PCV to the intake vs. the atmosphere. Modern engines do weird things when you make a closed loop system into an open loop one...

[MattM]

It's worked perfectly fine for the last two years.  I was thinking about a compression test but power has been fine and it's not blowing smoke out the exhaust.

[Sol Asylum]

For me, step 1 would be to do a compression check. Make sure the oil isn't a sign of excess blow-by. Step 2 would be to get a catch can, plumb it in line, and go back to venting the PCV to the intake vs. the atmosphere. Modern engines do weird things when you make a closed loop system into an open loop one...

Agreed, do a compression check.  Boosted engines won't have oil come past the rings like an NA when the rings go bad.

[TomatoSoup]

As I said on the big board, gas in the oil is generally a signifier that the seal(s) has gone on your HPFP (high pressure fuel pump) and that you need to replace it. I guess it could've gone badly enough that it's pressurizing the top end, but not sure.

[elff]

As I said on the big board, gas in the oil is generally a signifier that the seal(s) has gone on your HPFP (high pressure fuel pump) and that you need to replace it. I guess it could've gone badly enough that it's pressurizing the top end, but not sure.

X2

[MattM]

Ok...so you guys have heard of this type of thing being the fuel pump?  In this case I would have to drop the fuel tank to get at the pump correct?

[TomatoSoup]

Ok...so you guys have heard of this type of thing being the fuel pump?  In this case I would have to drop the fuel tank to get at the pump correct?

No and No.  The HPFP is attached to the top of the engine, just in front of the driver. See: https://www.solsticeforum.com/threads/replacement-of-my-high-pressure-fuel-pump-hpfp.141657/

As I said before: "I guess it could've gone badly enough that it's pressurizing the top end, but not sure."

[Dave@DDMworks]

That nipple where you have the filter hooked to has no baffling behind it to stop oil vapor from coming out through there. That is why there is a check valve on the stock piece that goes to the intake. There is supposed to be a one way flow of air from the intake to the valve cover through that hose only, so no baffling is needed on the back of that nipple. The nipple on the front of the valve cover has to go through a bunch of baffling inside the valve cover to catch oil vapor, sort of a built in catch can.

None the less, if you are getting excessive oil out of that nipple the only cause I can think of would be a big increase in crank case pressure caused by blow by in the engine. You should also check the inlet to the turbo for oil also, as you should be getting more coming out of the nipple on the front of the valve cover also. Most likely if you remove the black plastic intake tube you will find oil where it meets the turbo inlet. Do a compression and leakdown check, I am guessing that will show you what is going on with your engine.

As I said on the big board, gas in the oil is generally a signifier that the seal(s) has gone on your HPFP (high pressure fuel pump) and that you need to replace it. I guess it could've gone badly enough that it's pressurizing the top end, but not sure.

Since the fuel is directly injected into the cylinder, there would be no way to pressurize the top end of the engine with fuel pressure. If he is getting blow by from one or more cylinders, most likely that is where the fuel is also getting into the bottom of the engine and oil causing the smell.

[TomatoSoup]

Since the fuel is directly injected into the cylinder, there would be no way to pressurize the top end of the engine with fuel pressure. If he is getting blow by from one or more cylinders, most likely that is where the fuel is also getting into the bottom of the engine and oil causing the smell.

But, Dave, my understanding is (I haven't had this happen personally) that a prime symptom of failing HPFP is gas in the oil.  Again, my understanding, the seal between the HPFP piston and cylinder fails allowing fuel to leak down past the piston and into the oil supply. 

My point was that - extrapolating from the above - if the seal fails badly enough (maybe) the fuel by-flow could pressurize the crank case.

[Dave@DDMworks]

But, Dave, my understanding is (I haven't had this happen personally) that a prime symptom of failing HPFP is gas in the oil.  Again, my understanding, the seal between the HPFP piston and cylinder fails allowing fuel to leak down past the piston and into the oil supply. 

My point was that - extrapolating from the above - if the seal fails badly enough (maybe) the fuel by-flow could pressurize the crank case.

If that seal between the HPFP and the cylinder head was leaking, it would be extremely easy to check by pulling the valve cover, with so much fuel coming in the back of the cylinder head, it would be very clean in that area. Also, with enough fuel to come through to pressurize the crank case, the oil level would appear very high on the dipstick, it would take a lot of pressurized fuel to raise the pressure in the crank case enough to cause excessive flow out of that port on the side of the valve cover.

[Sol Asylum]

The fuel in the oil due to a failing fuel pump is probably the loss of fuel pressure which causes the fuel to not atomize properly as it passes through the injector thus the fuel flows as a stream or large drops leaks past the rings and into the oil.
 

[MattM]

Either way...I'm thinking my engine is shot, which is why oil is shooting out of that port.  I've had nothing but bad luck with this car to be honest....

[MattM]

That nipple where you have the filter hooked to has no baffling behind it to stop oil vapor from coming out through there. That is why there is a check valve on the stock piece that goes to the intake. There is supposed to be a one way flow of air from the intake to the valve cover through that hose only, so no baffling is needed on the back of that nipple. The nipple on the front of the valve cover has to go through a bunch of baffling inside the valve cover to catch oil vapor, sort of a built in catch can.

None the less, if you are getting excessive oil out of that nipple the only cause I can think of would be a big increase in crank case pressure caused by blow by in the engine. You should also check the inlet to the turbo for oil also, as you should be getting more coming out of the nipple on the front of the valve cover also. Most likely if you remove the black plastic intake tube you will find oil where it meets the turbo inlet. Do a compression and leakdown check, I am guessing that will show you what is going on with your engine.

Since the fuel is directly injected into the cylinder, there would be no way to pressurize the top end of the engine with fuel pressure. If he is getting blow by from one or more cylinders, most likely that is where the fuel is also getting into the bottom of the engine and oil causing the smell.

Hey Dave, I have one hopeful question for you.

Is it possible that my engine is now making so much power (it only does it at WOT and full boost) that I'm just overloading that side of the PCV system? And if I put a one way valve on it I could still be ok? Like I said, it's only happening at WOT with higher RPMS.

[MattM]

I will say that it is pulling EXTREMELY hard!

[Dave@DDMworks]

Did you change the power of the engine? I read your original post as nothing has changed for 2 years and after the differential swap, you are getting the oil out of the filter?

When under full boost and WOT is going to be the worst case for blow by into the crankcase, leakdown and compression test will rule that out or let you know either way.

[MattM]

Did you change the power of the engine? I read your original post as nothing has changed for 2 years and after the differential swap, you are getting the oil out of the filter?

When under full boost and WOT is going to be the worst case for blow by into the crankcase, leakdown and compression test will rule that out or let you know either way.

Yes, kind of.  My car always had a weird hesitation after 5000rpms at WOT where it would pull then not pull etc.  ONce my MAP sensor finally went out it's been pulling really hard up to 6000rpms now. 

That said, after talking everything over with you I did add the line back to the nipple with the check valve at the end (but not running back to intake) and guess what?!  No more oil blowing out!  I go out and basically tak e it all the way through redline in 2nd and 3rd a number of times and to the best that I can tell I'm not getting more oil leaking.  I still have yet to burn off the oil that was shot everywhere, but it's lessoning and lessoning.  It still pulls really hard and no misses no smoke out the tailpipe.  For now, I'm just going to call it a win.

My oil does smell a tiny bit like gas though, so I'm guessing maybe I might be down slightly on one cylinder, but at this point I don't really care (as long as it runs and drives great).  Maybe I'll put some thicker oil in it to help with the blowby or something. 

Anyway Dave, thanks for the advise!  At least my car is drivable at this point!

[Uranium-238]

Did you ever get HP Tuners? That could definitively show you if it's the HPFP or not.

[08solsticegxp]

So....As the title says...

SO I took off the valve cover to intake tube with the Check valve because it was clogged and then I vented to atmosphere. IT's been running perfectly for over two years.

So right after I get the car back for the rear diff and do some WOT pulls it now is shooting like a table spoon of oil out that tube when I do a WOT pull, and when I cleaned up the oil it smells somewhat like gas as well. I've attached a pic of the filter over that tube so you know where I'm talking about.

My car runs and drives great and this only happens at WOT. Does anyone have any idea why it would do this, or what I could do short of getting a new engine?

GOd I really hope this is somehting simple!! If not I'm torching this car!!!

I'd appreciate any help you guys can give me.

(Image removed from quote.)

The service manual says the PCV one way valve (the one that you removed) is used to prevent the turbo charger from pressurizing the camshaft housing and force oil and gases out. I would recommend putting your tube back on with the one way valve. I realize you mentioned that everything was just fine for a few years, but if you still have the tube, you can get a new PCV valve for under $20. Keep in mind, if a little air filter on that tube that you have was going to work, the manufacturer would have gone that route since its cheaper than a metal flexible tube with a one way valve.

It won't hurt to give it a try. You can always return the PCV valve if you put it on there and find out it didn't solve your issue.

You can also check the evap system. There should be a valve or a solenoid that will keep things closed off when the turbo is in use... The fact you say you are smelling gas also has me wonder if you have an issue with the EVAP solenoid which is just left of the MAP sensor on the intake manifold. I believe you can clean that out with WD40, but double check on that one.

[DeepBlueGXP]

LNF PCV valve is actually in the plastic intake manifold.  When you take off the manifold,  you will see a 3/8 drive slot,  place a socket extension in it and pull to remove.  You can test it by blowing in either direction.  Should only go one direction.  Replace that and pressurized intake air will not blow into the engine.

[MattM]

The service manual says the PCV one way valve (the one that you removed) is used to prevent the turbo charger from pressurizing the camshaft housing and force oil and gases out. I would recommend putting your tube back on with the one way valve. I realize you mentioned that everything was just fine for a few years, but if you still have the tube, you can get a new PCV valve for under $20. Keep in mind, if a little air filter on that tube that you have was going to work, the manufacturer would have gone that route since its cheaper than a metal flexible tube with a one way valve.

It won't hurt to give it a try. You can always return the PCV valve if you put it on there and find out it didn't solve your issue.

You can also check the evap system. There should be a valve or a solenoid that will keep things closed off when the turbo is in use... The fact you say you are smelling gas also has me wonder if you have an issue with the EVAP solenoid which is just left of the MAP sensor on the intake manifold. I believe you can clean that out with WD40, but double check on that one.

After speaking with DDM I did replace that tube.  I'm not running it through the intake just using the check valve on it and obviously no more oil.

Would the evap solenoid going bad cause a code to be thrown?

[Steelmesh]

You may consider adding a catch can in that PCV loop if gunk is building up inside your intake tract and manifold.  Maybe pop off the tube on your throttle body and see how the throttle plate and bore looks, would be a tell-tale if the PCV is pulling in a lot of garbage.

[MattM]

You may consider adding a catch can in that PCV loop if gunk is building up inside your intake tract and manifold.  Maybe pop off the tube on your throttle body and see how the throttle plate and bore looks, would be a tell-tale if the PCV is pulling in a lot of garbage.

I probably will after this, but I'm just happy to have fixed the biggest problem for now.  I'm still going to have to flag down the issue with the oil vaguely smelling of gas, but I don't I'm just happy I got the major thing fixed at the moment.