idle changing when removing oil cap? help!!!
Thread Starter
12 Second Club
Joined: Nov 2005
Posts: 1,847
Likes: 0
idle changing when removing oil cap? help!!! hey guys i got a question for you.
when the car is running and you remove the oil cap is the idle suposed to change?
could thins be because of my catch can? is it set up right?
help me out guys i dont want to be hurting my engine.
when the car is running and you remove the oil cap is the idle suposed to change?
could thins be because of my catch can? is it set up right?
help me out guys i dont want to be hurting my engine.
It's because of the additional un-measured air entering your engine. Because the PVC system is connected to the intake &/or valve covers/valley cover, when the oil cap is removed, the intake is sucking additonal, un-measured air into the engine through the oil fill opening. Air travels into the oil filler & then either out a valve cover, into the intake or down the push rod clearance in the heads/block, into the crank case, out the crank case through the valley cover & into the intake, depending on your PCV routing. None of this air passes through the MAF, so, it leans out the mix & changes the idle RPM. It's actually a sign that your car is still making good vacuum.
looks good to me.
hose from the TB to the front passenger side of the valve cover
hose from the rear of the drivers side cover, into a T then the other side of the T going to the rear passenger side valve cover. then the outlet of the T running up into the catch can, and then into the vacumm port on the intake manifold.
was thinking you wanted the PCV valve between the can and the manifold. not sure.
hose from the TB to the front passenger side of the valve cover
hose from the rear of the drivers side cover, into a T then the other side of the T going to the rear passenger side valve cover. then the outlet of the T running up into the catch can, and then into the vacumm port on the intake manifold.
was thinking you wanted the PCV valve between the can and the manifold. not sure.
Trending Topics
TECH Addict
Joined: Dec 2001
Posts: 2,907
Likes: 1
From: Bergen County, NJ
You have the lines on catch can reversed and yes, PCV between the catch can and the manifold, not before it like you have now. the PCV placement doesn't make a huge difference but you basically want the fumes unrestricted running to the catch can lower connector. Then vacuum through the pcv to the upper connector of the catch can.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
TECH Addict
Joined: Dec 2001
Posts: 2,907
Likes: 1
From: Bergen County, NJ
Look at it this way - you don't want the intake drawing from the bottom were the oil and condensation has gathered, you want it drawing from the top of the catch can after the wire mesh filter. So you want the oil and steam to enter the bottom, be filtered by the mesh and then cleaner air drawn from the top.
TECH Addict
Joined: Dec 2001
Posts: 2,907
Likes: 1
From: Bergen County, NJ
I stand corrected. I looked up the manufacturers install instructions, they have the dirty air from the engine entering the top and the cleaner air from the side of the catch can going to the intake. Sorry for the mistake.
