PCV Valves and Check Valves...questions about both.

[4gfun]

I have a few questions about PCV valves.

Being in this game for a long time, I have always heard that non-OEM PCV valves are a bad thing.

Questions:

1) Is a cheapo auto parts store still "bad" if you put a one way check valve in front of it?

2) I read that you can run a one way check valve instead of a PCV valve...but how is that when there are no threads on the plastic check valve? I have no emissions in my area so I don't care.

3) If OEM is really the only way to go, where can I get a good price on them? STM usually has great prices but the OEM one is $25. If you all say that a non OEM PCV valve is still not ok even with a one way check, I need to know where to get them without paying that much if possible.

Thanks!

 

[Spoolin98]

Brand new OEM ones are known to leak. If I were you I would just use the one you have or buy a cheap aftermarket PCV valve and put a good check valve in the line. As long as your PCV valve opens and closes freely you can use it. It doesnt have to seal because your check valve is going to do that for you. The check valve will stop the boost pressure before it gets to the PCV valve. You just have to make sure the PCV valve opens freely so the system works correctly under vac.

 

[4gfun]

Thanks, wasn't there something inherently inferior about PCV valves and their ability to let out enough crack case pressure?

Brand new OEM ones are known to leak. If I were you I would just use the one you have or buy a cheap aftermarket PCV valve and put a good check valve in the line. As long as your PCV valve opens and closes freely you can use it. It doesnt have to seal because your check valve is going to do that for you. The check valve will stop the boost pressure before it gets to the PCV valve. You just have to make sure the PCV valve opens freely so the system works correctly under vac.

 

[Silver71]

I'd like a little more info on this subject as well. Not intending to thread-jack...

Here is the link that is commonly posted for these check valves:
US Plastic Corp.

My question is, what SIZE does one need to order to fit the line?

I ordered an OEM PCV valve ($6.99 from JNZ) as preventive maintenance as I'm installing a new powdercoated valve cover, stainless bolt kit, valve cover gasket, and oil cap gasket so I figured I'd make sure the PCV was in tip-top shape as well. The reason for this is I'm leaking oil from my valve cover gasket, and some from the oil cap gasket. I'd like to add a check valve to get the job done right.

 

[Rsawd95dsm]

3/8 is what I used.

 

[4gfun]

No it's quite alright.

I just ordered a 3/8" as well. Worked just fine on my GVR4 and so I got the same for my 1g.

I'd like a little more info on this subject as well. Not intending to thread-jack...

Here is the link that is commonly posted for these check valves:
US Plastic Corp.

My question is, what SIZE does one need to order to fit the line?

I ordered an OEM PCV valve ($6.99 from JNZ) as preventive maintenance as I'm installing a new powdercoated valve cover, stainless bolt kit, valve cover gasket, and oil cap gasket so I figured I'd make sure the PCV was in tip-top shape as well. The reason for this is I'm leaking oil from my valve cover gasket, and some from the oil cap gasket. I'd like to add a check valve to get the job done right.