PCV valve average lifespan

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In general, after how many miles have you seen PCV valves go south?
Does it depend on manufacturer brand? On synthetic vs conventional oil?
 
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Many vehicle engines today don't have PCV valves in the traditional sense, the have PCV ports with no valve at all. My 2006 Cadillac 3.6 uses only a port. My 2013 Silverado 5.3L had only a port. And my 2015 Silverado 6.0 only has a port. I would venture to guess that ports are more common than valves in a lot of engines.
 
About 60k with a Honda one on average specifically on the Accord. Usually the internal spring breaks around then. On the pre-2002 models around 100k. If using an aftermarket one, which I wouldn't recommend about 30k miles.
 
Originally Posted By: KrisZ
11 years, 145k miles and counting on my Mazda 3. ...
The original was apparently still OK on my Mazda at nearly 34 years and 606K miles. They were all-metal back then. PCV system was still sucking fresh air into the intake filter at idle (as opposed to exhaling blowby fumes).
My even earlier cars had no PCV systems, unfortunately. (Draft tube and perforated valve cover on the old Chevy; no fresh intake, with blowby fumes directed to clean side of air cleaner on Subaru, until I modified it)
 
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Originally Posted By: CR94
Originally Posted By: KrisZ
11 years, 145k miles and counting on my Mazda 3. ...
The original was apparently still OK on my Mazda at nearly 34 years and 606K miles. They were all-metal back then. PCV system was still sucking fresh air into the intake filter at idle (as opposed to exhaling blowby fumes).
My even earlier cars had no PCV systems, unfortunately. (Draft tube and perforated valve cover on the old Chevy; no fresh intake, with blowby fumes directed to clean side of air cleaner on Subaru, until I modified it)

I'll be retrofitting a Mazda 323 PCV valve when it comes time to change mine, then.
 
Back in the '90's we had a dozen PVC valves of various sorts hanging on a wall...we used at least one a week. A lot of things changed when we went unleaded fuel...exhausts stopped rotting, I don't know why PVC valves stopped failing. It was usually the spring rusting and breaking. These days I keep old PVC valves, and swap a clean one for a dirty one. Cleaning with brake clean etc doesn't work, I soak them overnight in a water based cleaner.
 
They don't necessarily go bad all at once. Last one I replaced was a poor quality aftermarket one installed by a mechanic. I replaced it with a Motorcraft one that I could could not blow back through, and yes your car does idle better with one that is working properly.
 
My Jeep's PCV is simple, but I replaced it a few years ago because the rubber grommets on the valve cover were hard plastic. I just did that along with the valve cover gasket.

The setup on the Volvo in my sig is a whole other story. Compared to other photos on the web, it had to be the cleanest, highest mileage Volvo PCV out there.
 
Originally Posted By: Silk
These days I keep old PVC valves, and swap a clean one for a dirty one. Cleaning with brake clean etc doesn't work, I soak them overnight in a water based cleaner.


My 1986 car doesn't have one, just a baffled breather in the rocker cover, but if I was doing this I might try a soak in old brake fluid, followed by a water flush.

I suppose it might attack plastics on some, though.
 
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Changed mine after a bit of oil consumption was noticed and it solved the consumption. Im going to change mine every 60k miles proactively..10$ for the part and 5 minutes to change, Im not going to overthink its necessity or not.
 
In most engine designs, PCV valve failures are rare. The problem is in that rare event of failure, you can cause some serious sludge and other cascading failures. Still is prudent if ones vehicle is on a OEM recommended change schedule, to adhere to that as preventative maintenance rather than reactive maintenance and higher cost later for not wanting to change a $5-$50 PCV valve until actual failure.
 
Changed mine @170k miles just because. Old one rattled when I shook it so it was likely still good.
 
Or the broken spring inside of it making noise.
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Originally Posted By: DrRoughneck
... I'll be retrofitting a Mazda 323 PCV valve when it comes time to change mine, then.
If you can find one. I admit I did have to replace the PCV grommet and hose, once apiece, although the valve itself never failed or clogged.
 
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Our beloved old '97 Mazda MPV started pinging under load when it was relatively new, c. '95. This started at around 120K km. Over the next number of years I tried all sorts of things - premium fuel, gasoline additives, and colder-range plugs, all to no avail.

By 2014 it was at 299K km and had various oil & coolant leaks. It was fix it or dump it.

I started pulling taking things off, determined to go as far in as required to fix the leaks. The coolant leak (singular) turned out to be just loose intake manifold bolts, but I changed the metal gaskets anyway. Changing the front cam seals, valve cover gaskets, and the five O-rings up top (distributor shaft, distributor mounting plate, distributor blanking plate, PCV valve mounting plate, and PCV blanking plate) fixed the oil leaks, but this was the great thing - I'd never known where the PCV valve was. Found it tucked way down when I removed the intake plenum. Checked it, and it was blocked solid. No rattle, and couldn't blow air through either direction. Changed it out, and what a delight! No more pinging under any conditions, and way more power (possibly due to winding up to 5K RPM just for the sheer pleasure of it). I wish I'd done it 10 years before, but will not make that mistake again.

Our Mazda 5 has a Ford Duratec 2.3 engine, and per the FSM the IM has to be removed to change the PCV valve. I'll likely do it anyway.
 
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