Pcv valve? Where are you?

A swivel head ratchet wrench works fine from below, no need to used sawed off wrench. No offence, but this is no longer about common sense. You're way is good if you're pulling the intake manifold anyway. But to just access the pcv valve? I wouldn't do it that way.

There's two ways to get at it, take your pick?

 

Why won't anyone say why we'd need any of those approaches in the first place?

Posted via the PriusChat mobile app.

 

Haven't found a bad pcv?

 

Why, because PCV's fail at some point. I'm on number 3 and each one gets about 80,000 miles. Part of the reason my be engines with slack clearances in the piston ring department and 0w20 synthetic oil.

 

Nope. Maybe I'm not looking for them correctly? All I know is I've changed a few and they made no difference.

Posted via the PriusChat mobile app.

 

How did yours fail? How did you know they failed?

Posted via the PriusChat mobile app.

 

I've changed a few, never a bad one, even at 200k miles. Always rattled like the new one I put in

 

Right? That's what I was thinking. I've never found a good reason to sell a PCV valve replacement on a Prius. If owners want to replace them as a maintenance item even it's not recommended by Toyota, they have the right to. If I was going to recommend one to a customer, I need a good reason to.

Posted via the PriusChat mobile app.

 

I think the best solution is to remove the intake manifold, clean it thoroughly, replace its gaskets, replace the PCV valve, and clean the EGR pipe... all in one operation. And do it every 100,000 miles. While you're at it, with the air box (engine air filter housing) removed, thoroughly clean it.

It's not very difficult. Mendel is right that PCV replacement is faster from below, but Swampy is right that PCV replacement is MUCH easier if you've removed the intake manifold. So if you can, I recommend that you perform the three services together: PCV Valve replace, intake manifold clean, and EGR pipe clean.

 

The goopy/milky "puddle of doom" in the bottom of the intake manifold and the PCV tube with the same tell tale signs. Replacing the valve removes the problem for another ~2 years or in my case around 80,000 miles. As you can imagine, with that kind of mileage I rarely drive the can for just a few minutes to where it doesn't fill get to temperature.

The valve also still rattles when removed but that's not always indicative of a working valve.

 

When I took off my PCV valve at 73k miles, I cleaned it throughly with brake cleaner. After ~2 minutes of cleaning, the buildup and varnish was removed and it looked and sounded brand new.

Correct me if I'm wrong because I don't understand how these could break. The plunger and housing look like they're made of stainless steel.

 

FWIW, I checked price for PCV valve at our nearby dealership: $14.19 (Can). Suprisingly reasonable, and Canadian prices are typically higher. Got one for a Civic recently, it was around $32.

 

Do you clean up the "puddle of doom" when you replace the PCV valve? What are the "tell tale signs?"

Posted via the PriusChat mobile app.

 

Maybe "puddle of doom" is normal?

Not as bad as "Our EGR Cooler of Eternal Blockage"?

 

When it comes to cars, I'm not the kinda guy to leave a big oily, chemical, slightly milky mess in the "bowl" at the bottom of the intake manifold. Such a mess gets the PCV tube removed for inspection which lead to the manifold and PCV being removed.

I started getting a few mpg less, started using a bit more oil and things generally weren't as smooth as before.

 

If that puddle is normal, especially the milky residue, then maybe both are indicative of a design that promotes overcooling of the engine and egr gasses. Typically, in an engine, when you get upto temperature, you start to boil off any condensation in the engine. I live in a city where 100+F is common and I still get those signs every couple of years. Maybe I need to go live somewhere hotter

What happens with the EGR if you pull the coolant hoses and connect them together without going through the cooler itself? Is that really an EGR cooler or is it a heat exchanger that heats the coolant to get the engine up to temp faster? Putting a device in to cool the EGR seems odd, heating the coolant to get to temp faster sounds more plausible, IMHO.

 

Certainly with enough carbon buildup, the valve could be held open. And there is a solenoid inside there which operates at fairly high temperature, pressure, and under constant vibration. I agree that it's durable, but anything can break.

 

I pulled off a PCV valve on a 2005 with 200k miles. It rattled nicely when I took it off, sounded the same as the new one I put in. I tried to clean the gunk off it with some throttle body cleaner and see if I could reuse it. After letting it sit for a day, the rattle actually was worse after cleaning. Like it gunked up. So cleaning probably isn't a good idea, just replace as needed

 

Sounds like an "evangelist" might be useful.

 

When I first did a throttle body cleaning I noticed something shiny down there, but not milky. This was maybe around 40K kms, practically a new car. It's a tablespoon or two.

There is a coolant heating system, it's on the exhaust, just beyond the Catalytic Converter, IIRC. The EGR cooler function is per it's namesake. But apparently it's about as effective as store doormen on Boxing Day: it's swamped by the rush of hot gasses.

On 3rd gen the EGR inlet is upstream of the Cat, and on 4th gen the EGR inlet is downstream of the Cat, which seems to me to be tacit admission that third gen EGR cooler is a fail.