I understand that a pcv valve is supposed to be a one way valve...correct?? Well I got a new one today and decided to blow into one end, which let the air pass fine, when I blew into the other the air was more restricted but still came thru...is the valve defective or are they supposed to do that?
pcv valves
- Thread starter lucerne06
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They might not seal 100% in the one direction. Should seal for the most part.
Buy an extra if they are not expensive and try that one......
Buy an extra if they are not expensive and try that one......
Always buy an OEM... Never use an aftermarket. You are asking for problems and/or oil burning IMO.
Originally Posted By: StevieC
Always buy an OEM... Never use an aftermarket. You are asking for problems and/or oil burning IMO.
For some cars you can have problems with an aftermarket PCV. So StevieC has a point.
Always buy an OEM... Never use an aftermarket. You are asking for problems and/or oil burning IMO.
For some cars you can have problems with an aftermarket PCV. So StevieC has a point.
pcv valves are designed to go one way, but its ok that the air gets past when you blow the opposite direction, mainly cuz the blow by gases get sucked into the intake not blown into the motor.
here is the crazy thing..it's a prizm ,,it has a toyota engine 1zz-fe...depending on where the engine was built,,you have two pcv applications..either a 3/8" or 16 mm thread gauge.
anyway..if I go to chevy,,they give me AC delco..If I go to toyota..they give me toyo...
two differnt parts..two different manufactures..so maybe a good quality aftermarket is better?. I am confused though..thats for sure..
anyway..if I go to chevy,,they give me AC delco..If I go to toyota..they give me toyo...
two differnt parts..two different manufactures..so maybe a good quality aftermarket is better?. I am confused though..thats for sure..
Back when PCV valves first came out (in the sixties) we were told that their primary function was to prevent a back fire from traveling into the crankcase. Makes sense since a hose sans PVC valve would ventilate the crankcase.
Blowing or sucking into a PCV valve doesn't tell you much. It takes constant vacuum to operate, and even when seated, it may have bypass holes in it.
The design of a pcv valve is to evacuate crankcase vapors and keep the crankcase at a negative pressure. The ball is there in the event that for some unique chance that liquid oil comes in contact with the valve, the ball shuts off the vacuum and avoids pulling oil into the pcv system. The proper way to check the valve is to check it with the engine running, put your finger over the valve and make sure that the ball shuts off the vacuum. +1 on the OEM parts. I have replaced many aftermarket valves for various failures. The most common is improper spring pressure that causes a buzzing when running.
The PCV replaced a blow-by tube, which basically was a tube that vented the vapors towards the bottom of the engine. My Kubota diesel tractor had one.
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Originally Posted By: harleyultra06
The proper way to check the valve is to check it with the engine running, put your finger over the valve and make sure that the ball shuts off the vacuum.
Which side of the valve?
The proper way to check the valve is to check it with the engine running, put your finger over the valve and make sure that the ball shuts off the vacuum.
Which side of the valve?
Originally Posted By: Petrou
pcv valves are designed to go one way, but its ok that the air gets past when you blow the opposite direction, mainly cuz the blow by gases get sucked into the intake not blown into the motor.
Yes, but the correct amount of air has to be let through, not more or less because the computer and engine has been calibrated for this amount.
pcv valves are designed to go one way, but its ok that the air gets past when you blow the opposite direction, mainly cuz the blow by gases get sucked into the intake not blown into the motor.
Yes, but the correct amount of air has to be let through, not more or less because the computer and engine has been calibrated for this amount.
the PCV valve for the PRIZM is same thread as the COROLLA's PCV valve of same year(s) . Know this for fact , bought it from TOYO parts department and changed it that day . Not all that difficult to replace , used an open end adjustable wrench . Can be installed one way only .
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What ball? Never heard of or seen one in a PCV valve.
There are different designs, and not all have the same metering systems. Some have light springs, some are gravity, all us vacuum.
They also seal against backfire pressure [going the wrong way].
There are different designs, and not all have the same metering systems. Some have light springs, some are gravity, all us vacuum.
They also seal against backfire pressure [going the wrong way].
Originally Posted By: mechtech2
What ball? Never heard of or seen one in a PCV valve.
There are different designs, and not all have the same metering systems. Some have light springs, some are gravity, all us vacuum.
They also seal against backfire pressure [going the wrong way].
The PCV Valve on my Marauder has a ball in it, this one does not have a spring on it like the one on my small block chevy.
What ball? Never heard of or seen one in a PCV valve.
There are different designs, and not all have the same metering systems. Some have light springs, some are gravity, all us vacuum.
They also seal against backfire pressure [going the wrong way].
The PCV Valve on my Marauder has a ball in it, this one does not have a spring on it like the one on my small block chevy.
Originally Posted By: oilboy123
Originally Posted By: StevieC
Always buy an OEM... Never use an aftermarket. You are asking for problems and/or oil burning IMO.
For some cars you can have problems with an aftermarket PCV. So StevieC has a point.
I had excessive oil consumption and oil oxidation in my Astro Van. Turned out it was a cheap aftermarket PCV buzzing. Went back to ACDelco and problem instantly solved.
Originally Posted By: StevieC
Always buy an OEM... Never use an aftermarket. You are asking for problems and/or oil burning IMO.
For some cars you can have problems with an aftermarket PCV. So StevieC has a point.
I had excessive oil consumption and oil oxidation in my Astro Van. Turned out it was a cheap aftermarket PCV buzzing. Went back to ACDelco and problem instantly solved.
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