Missing almost 1 Quart of Oil in less than 1 Year.

Well it isn't exactly a metering valve at all. Just a check valve that opens during the engine operation to vent blow-by combustion gases from pressurizing the crankcase and blowing out the oil seals. It also prevents a backfire from entering the engine.

The old crankcase vent systems used to just use a draft pipe that vented to the atmosphere under the vehicle. New pollution standards made them recycle that gas back into the engine via the PCV System to burn.



https://www.gatestechzone.com/en/news/2021-06-positive-crankcase-ventilation

Below is an example of a draft tube system:

 

Doing any high speed driving? That tends to cause consumption to rise.

 

"Metering valve" was probably the wrong word. I'm not certain but I think the internal design of the PCV valve is such that the carefully-sized & shaped inner passage, in combination w/ a certain amount of calibrated spring tension, ensures that the valve linearly increases its resistance to the intake-side vacuum as engine RPM & vacuum increases. Rather than a pure check-valve which would tend to "pop open" at a set pressure threshold and then "pop closed" only a small amt. below the threshold.

 

You’re overthinking it, man. The spring has gravity at its back. Engine off, it closes the valve (but it would then be closed even without the spring). Idling, it’s slightly open. High RPM, it opens all the way. If that spring were to totally fail and the valve ends up sticking open, you would notice a rough idle, maybe even a misfire or a CEL for a vacuum leak. By god, by all means, it doesn’t break the bank to replace it. I just never had one on hand when I thought to check it during an oil change, so I just checked/cleaned it. I have no symptoms that indicate that it’s faulty.

 

Damn, you're harshing my vibe. I mean the vibe I was hoping to have of doing the right thing by spending $14 for a new OEM PCV valve, shipped, instead of just brakleen'ing out the current one which rattles just fine.

 

Yes a $3 check valve that could be gunked open. That'll let excess oil to be pumped up into the intake and into the combustion chambers.

 

I changed my pcv valve for the 1st time at 230k km. Decided to cut the PCV open to see what was inside.... some pics here : https://www.tacomaworld.com/threads/pcv-tear-down.780473/

 

I thought a quart in a 100 miles was reasonable on my 22R 300,000 plus then I could turn the engine over with one hand on the crank pulley with the plugs in.

Other then burning oil that little engine just keep on going . I just changed filters every 3000 miles or so.

 

I bet that thing smoked like a bong!

When I had that little Eagle Talon I lived in a mountainous region. Every time I'd go down the mountain it would hit high vacuum and smoke the cars out behind me. Also idling at the drive through it would do it. People probably cheered when I moved away

 

160K, change oil/filter when the service light comes on steady. Nothing more than that original untouched PVC valve. Toyota truck #3 the last 2 had 300+K

 

My 12 is about that maybe a little more since very first oil change I did myself

 

Issue: You go 8,000 miles between oil changes, tow a boat, and it's about a quart low...

Here is the fix: Change the oil at 5,000 mile intervals like Toyota recommends. Save a few bucks and re-fill with conventional, non-synthetic 5W-30 (you'll be fine) and OEM oil filter.

Result: Your total oil consumption will drop to: ZERO quarts between changes.

 

If someone goes to the trouble of a removal to inspect it, ("R") why not just replace it while it's out? Spending the $14 to R&R the part is the right decision.
("vibe")

 

Had a work truck like that in high school. Someone called the cops about it while going down the freeway. I told them it was a mosquito fogger. They didn't buy it.

 

Yes

 

Thank you very much everyone for the reply. Really love this community.

 

My 2014 with same engine at 122,000 and 5,000 mile oil change intervals: no oil consumption between changes.

 

Just change the oil every 5k miles and be done with it. Your engine will run so much better and for longer because of it.