Why replace an all-metal PCV valve?

People advise "replacing" PCV valves when they get sticky, but it seems that Toyota's all-metal ones (Tacomas, etc.) merely require cleaning with a solvent or just hot water and dish soap.

A PCV valve is just a weak spring-loaded stopper; a one-way port for crankcase gases. As long as the spring isn't broken (it doesn't seem to have a tough duty cycle), shouldn't it last indefinitely?

I've seen plastic types that look a bit flimsy, but I don't see why a sturdy metal one needs to be replaced. Any thoughts?

JT

Reply to
J. Tyler
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The original PCV in my 1990 Prizm was plastic. That PCV was still in place when I sold the car with 285k miles. I may have sprayed some carb cleaner thru it a few times ... that's all. BUT... I did run Mobil1 motor oil and changed it every 4-5k miles.

Reply to
Philip®

We replace them because we dont "service PCV valves", but if a DIY'r wants to, its fine. I you change your oil enough, you wont even need to clean it.

Reply to
MDT Tech®

Every year before inspection I would replace the PCV valve on my old Sentra, including a full tune-up. All it took was a little bit of grunt work and a cheap part from 'The Zone"

~Bhuvan

Reply to
Bhuvan

In 12 years and 285,000 miles, I only cleaned the PCV in the ol Prizm a couple of times. Never changed it and it worked fine. Then again, I ran Mobil1 and changed it every 4-5k miles too. No varnish at all inside the engine. While PCVs are an inexpensive "easy sale" part,

*IF* you find yours gunked up at all, then you already have a problem with crankcase deposits and slime.
Reply to
Philip®

I just did it every year per my mechanic who suggested it when it failed for the first time. The valve still worked, but tha newer one worked better!

~Bhuvan

Reply to
Bhuvan

And that's fine, replacing it yearly wont hurt a thing and doesn't cost much. I'd rather see it done, than never. We chastised Charlene for never taking car of her van, we cant chastise folks who take real good care of things.

Reply to
MDT Tech®

By what criteria did the replacement valve "work better?"

Reply to
Philip®

You would notice a difference in the sound of each when you shook them. The old one sounded 'duller', more muted. The new one was more brassy, if you know what I mean. Since it was only

Reply to
Bhuvan

hahahhaha! Metal sounds "chinkie chinkie" while plastic sounds "knockity knockity" (duller). Oh... that's a good one! More to the point is OE valves often have higher flow rates than generic aftermarket valves. Not always ... but often.

Reply to
Philip®

It was just a b%$*h to remove!!

Same here. Had to pry and twist, bending the base. Next time, let's try replacing the rubber grommet also. May have hardened over time.

Reply to
Daniel M. Dreifus

Both new and old valves were metal

~Bhuvan

Reply to
Bhuvan

True, but you could see some 'crud' (word used loosely; don't read too much into it!!) inside the old valve, while, obviously, the new one had no 'crud'.

Reply to
Bhuvan

A Thought:

In light of what Mr. Sig Sauer had to say about changing PCV valves, I am going to keep my old PCV valves in a ziplock baggie. We've got two (2) unsludged Siennas, and on the '98 I had my mechanic change the valve at 60k (bought it w/ 54k on the clock) and save the old one. It was not plugged, and I'll continue to change it every 30k miles and keep the old valve in a labeled bag. That should go a long way towards reassuring an inquisitive buyer when the time comes. In the unlikely event of sludge, it'll also help to prove timely maintenance.

PCV replacement is a semi-ugly job on a Sienna, 'cuz you need some long pliers to get back there. I didn't try it myself; I'm too worried to have crud fall into the opening.

-Mathias East Lansing, MI

Reply to
Mathias Steiner

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