Change your PCV valve

Let’s see here…on a 4runner a PCV cost less money than almost any other part on the car. It takes no time to replace. The job is low-risk and hard to botch (besides using red loctite). A bad PCV has potential to cause expensive problems on older cars (or maybe even cars prone to gasket failures, like the 4runner timing cover).

Applying logic to that combination of factors makes easy to conclude that on 4runners it’s a very reasonable thing to do as a *preventative* maintainance item, even before it fails or gets gummy.

It would only be silly if it was a labor intensive, difficult job, on a clapped out old beater. I mean, it’s logically bordering on “penny wise, pound foolish” silliness to ignore it.

ETA: So maintenance is always silly unless it leaves you stranded?

 

When does the timing cover usually start leaking, how many miles?
Serious question.
PCV valve contribution to this issue?
Hey, I’m just wondering out loud. Not trying to complicate things…. I’m just thinking since we all know it “can” cause positive pressure to build.

 

I agree with you if the PCV in 5th gen 4Runners were well documented as failing. As far as I know they aren’t.

 

I seems like the timing cover leak not common, but not rare. I’ve even seen a post on here of this leaking on a new 4runners.

To me it seems like the timing cover leak isn’t worth worrying about. And even if it does happen, it may not be worth the thousands it would take to fix it.

But it does seem like that gasket has a lot of real estate to cover, and I’d want to give it the best odds of not leaking over the course of my ownership.

 

Just changed out my PCV while changing the spark plugs two days ago. 119K miles.
Plugs were in very good shape.
PCV was still functioning with slight carbon buildup.
Compared to the new valve the ball inside the old valve was noticeably not moving as quick as the new one.
Sprayed it with brake cleaner and started working as new.
My take would be to change out your PCV while doing your plugs since you're right there.

 

As much as I like a “data-driven decision making”, this approach is meant to be applied to complex, high stakes situations where “doing something” carries a high level of risk of making things worse.

This is a simple breather…the same design probably used for the last hundred years…a ball in a tube. They get gummy eventually. They may get more or less gummy depending on how the vehicle is used. You should be able to deduce the benefit of changing it without needing “documentation”.

I would agree with you if half the engine needed to be disassembled to replace the PCV valve. It doesn’t. The fact that it’s easy to replace is more of a benefit of the 4runner design, as it’s easier than other cars to keep it in tip top shape.