A PCV valve is internally spring loaded?
Thread Starter
Melting Slicks
Joined: Jan 2002
Posts: 2,238
Likes: 4
From: Milan
A PCV valve is internally spring loaded?
every manual says to shake the PCV valve to hear a rattlig sound in order to test it.
If you can hear (and feel) the rattle your PCV valve is good. Mine sounds like this.
I found on the TirdGen.org an Image where I can se the internal of this valve. It seems spring loaded. Mine Does non seems spring loaded cuz the internal plate can go further in the body valve without any effort..
Since I haven't found the cause of a abnormal oil consumption on my engine, I'm suspecting that a defective PCV valve can be the culprit.
To make the story short:
Is this valve spring loaded? and if yes, this spring should be so weak as mine, or putting a finger on it I have to feel a slight drag? (due to the force of the sspring..)
Thanks
-Beppe-
If you can hear (and feel) the rattle your PCV valve is good. Mine sounds like this.
I found on the TirdGen.org an Image where I can se the internal of this valve. It seems spring loaded. Mine Does non seems spring loaded cuz the internal plate can go further in the body valve without any effort..
Since I haven't found the cause of a abnormal oil consumption on my engine, I'm suspecting that a defective PCV valve can be the culprit.
To make the story short:
Is this valve spring loaded? and if yes, this spring should be so weak as mine, or putting a finger on it I have to feel a slight drag? (due to the force of the sspring..)
Thanks
-Beppe-
Drifting
Joined: Nov 2002
Posts: 1,593
Likes: 0
From: Mobile AL
St. Jude Donor '05
Yep, it's spring loaded. A VERY light spring. When the internal pressure in the block becomes high enough, it overcomes the resistance of the spring, opens up, and the crankcase is vented to the intake. Simple effective means to keep oil blow-by and crankcase emissions to a minimum. "If it rattles it's good" is a good test, but they are cheap enough that I replace mine once a year just for grins.
Advanced
Joined: Feb 2004
Posts: 51
Likes: 0
From: Mission Viejo CA
How much oil are you using? GM "allows" about 1 quart per 1000 miles! A PCV valve will not normally cause high oil consumption; especially one such as yours where you can "hear" it. Pull the plugs and examine them. A more likely problem (on SBC engines) is bad valve seals. If the motor has no visible leaks but is using some oil, it is probably bad valve seals. I have changed these on other SBC engines, typically around 75K miles. Have used Fel-Pro with good success. It also wouldn't hurt to check the intake manifold gaskets as well. I used an air chuck with the heads still on the vehicle. I've heard of using the "rope trick" but haven't personally tried it. The rope trick: Stuffing nylon rope into a cylinder through the spark plug opening to keep the valves from falling into the motor. Should be done at TDC, of course.
Pro
Joined: Sep 2003
Posts: 670
Likes: 1
From: charlotte nc
Originally Posted by mvmechanic
How much oil are you using? GM "allows" about 1 quart per 1000 miles! A PCV valve will not normally cause high oil consumption; especially one such as yours where you can "hear" it. Pull the plugs and examine them. A more likely problem (on SBC engines) is bad valve seals. If the motor has no visible leaks but is using some oil, it is probably bad valve seals. I have changed these on other SBC engines, typically around 75K miles. Have used Fel-Pro with good success. It also wouldn't hurt to check the intake manifold gaskets as well. I used an air chuck with the heads still on the vehicle. I've heard of using the "rope trick" but haven't personally tried it. The rope trick: Stuffing nylon rope into a cylinder through the spark plug opening to keep the valves from falling into the motor. Should be done at TDC, of course.
Thread Starter
Melting Slicks
Joined: Jan 2002
Posts: 2,238
Likes: 4
From: Milan
I have ready to install this kit:
12511890 Valve Stem Seal Kit
This late model V8 seal kit includes 8 P/N 460483 intake seals, 8 exhaust seals, and 16 P/N 10214034 oil stem seals.
The engine i rebuilt 1 1/2 year ago and sice this it burn 1 quart every 500 miles!
The builder does not remember the seals He putted on...
Since Im suspecting an incorrect rings installation..
...I'm evaluating all others causes before to go deep in the real suspected problem.
I read somewhere that rings installed in the wrong side ( opposite) can perform good leakdown and compression test but can burn tons of oil.
-Beppe-
12511890 Valve Stem Seal Kit
This late model V8 seal kit includes 8 P/N 460483 intake seals, 8 exhaust seals, and 16 P/N 10214034 oil stem seals.
The engine i rebuilt 1 1/2 year ago and sice this it burn 1 quart every 500 miles!
The builder does not remember the seals He putted on...
Since Im suspecting an incorrect rings installation..
...I'm evaluating all others causes before to go deep in the real suspected problem.
I read somewhere that rings installed in the wrong side ( opposite) can perform good leakdown and compression test but can burn tons of oil.
-Beppe-
