Change your PCV Valve!!!

[Runnah]

Boy what a difference! Changed it Satruday and right away I noticed my car was zipper. The throttle response was improved and It seems to be idling a bit smoother. The old valve was rusty and I could tell the difference in the speed in which the new valve opened and shut compared to the old one.

Not bad for $10 and 5 mins.

Here is a good write up.

http://www.northursalia.com/modifications/drivetrain/pcv/pcv.html

 

[mikebike357]

How many miles are on your buggy?

 

[Runnah]

How many miles are on your buggy?

Since it was last changed? No idea.

But its rapidly approaching 90k.

 

[mikebike357]

What's the service interval on a PCV valve? 60k? Hmmm... must go visit my.subaru.com to look at the maintenance schedule. I know it wasn't part of the 30k...

 

[Runnah]

What's the service interval on a PCV valve?

 

[mikebike357]

Interesting... I guess I should replace mine then!

 

[seph]

Interesting... I guess I should replace mine then!

mine as well...

 

[Shorty]

We replace them at every 30k service but I didn't realize it would make a power difference. Cool.

 

[Runnah]

We replace them at every 30k service but I didn't realize it would make a power difference. Cool.

Didn't add power, just freed up lost power.

From what I've read they control the venting of gases from the crank case. I assume when the valve wear out and slows it increases pressure in the crank reducing performance.

But I could be wrong.

 

[mikebike357]

so kinda like when you know you have to fart but you can't so you feel really crappy?

 

[Runnah]

so kinda like when you know you have to fart but you can't so you feel really crappy?

Exactly!

 

[rallyXcramps]

We replace them at every 30k service but I didn't realize it would make a power difference. Cool.

Didn't add power, just freed up lost power.

From what I've read they control the venting of gases from the crank case. I assume when the valve wear out and slows it increases pressure in the crank reducing performance.

But I could be wrong.

Yes. In the old days the crank case vapors used to be vented to the atmosphere. These days the PCV(positive crankcase ventilation) is a controlled vacuum leak. The valve rapidly opens and closes, because of a spring inside it, as the intake manifold continuously sucks on it. Its a controlled vacuum leak because the computer has been calibrated for it. Its pulling any oil vapor into the intake reburning the fumes. On Subarus there are also(breather) tubes from the rocker covers to the air box. There is a negative pressure in the air box pulling the fumes from the top of the cyl head. This is not considered a controlled vacuum leak because its on the front side of the throttle, but it helps in the PCV actions. I believe the breathers enter before the air filter so the throttle doesn't get carboned up requiring frequent throttle cleanings. On VWs and Saturns the breather enters after the air filter causing gum or carbon build up on the throttle plates and intake runners. So, that's why Patriot and Evergreen replaces PCVs every 30k. The springs get weak and the chamber gets goooooy messing up the system.

 

[jeffcrider]

after browsing that how to website it really makes me want to do a garage day

so much fun to be had.