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PCV valve replacement

My 99 Saturn SL2 has been loosing oil (about a quart every 2-3 thousand miles) and it seems a possible culprit is the PCV valve.



So how exactly do I determine if the PCV valve should be replaced? Based on my records I got it replaced previously a bit less than 2 years and around 15000 miles ago.



Also, from my understanding a fouled valve could happen if I’m not changing my oil often enough. (I’ve been changing every ~3000 miles, regardless of the time between changes; it can sometimes be as much as 8 months.) However, if I should have been changing my oil more often, I suppose that might lead to it fouling up quicker?



My driving habits are such that I wouldn’t think it would be a problem. Despite the sometimes 6-8 months that sometimes go between changes, I do most of my driving on the highway in several hundred mile chunks. To explain, I’m a graduate student, so during school months, I typically only drive once or twice a week to pick up groceries and run errands. I put the real mileage on during the summer or when I travel during breaks. (This translates to roughly 2400 miles of every 3000 was done on the highway, traveling between locations several hours apart.)

One quart of oil every 2000-3000 miles is not a problem. A PCV valve is cheap and easy to replace, but I doubt that replacing the PCV valve will change the situation. You have an 11 year old car and some new cars use more than a quart of oil every 2000 miles. My first year of graduate school I had a 1947 Pontiac that I bought for $75 to make the 350 trip from home to the University where I did my master’s degree. It used a quart of oil every 250 miles. Fortunately, discount stores were just coming into existence about this time (1962) so I would buy a case of cheap oil and add a quart when necessary.

Let me add one more piece of advice: “Quit worrying”. I think worrying goes with the territory of being a graduate student. I have graduate students that even if they didn’t have any worries, they would worry about not having something to worry about.

The PCV valve is nothing but a one-way valve to allow the engine to draw oil vapor out of the crankcase. This keeps a positive pressure from developing in the crankcase, which would force oil into the combustion chambers.

It’s unlikely that your PCV valve is causing a problem, because your oil consumption is really not much of a problem and would be considered by probably every automobile manufacturer as completely normal, especially on a 12 year old car. If you’d like to check the valve, take it off the car and shake it. If it rattles, it’s almost certainly fine. If you’d like to change it, though, go right ahead. They’re only a few bucks.

Don’t be surprised if your oil consumption doesn’t change though. That sounds to me like normal wear.

If you pull the pcv valve out with the engine running and air is being pulled through it, then it’s working. You could clean it or change it if it is plugged. Two years old isn’t very old for a PCV valve. The only reason the valve is needed is to prevent an intake backfire from setting your engine oil on fire. Maybe there are other minor reasons.