• To celebrate the 4th of July, starting today (07/01/2025) all User Upgrades will be reduced by 10% (thru 07/08/2025) To use this special coupon use the code 2025-4th-10percent at check out. If you are already a supporter your existing package will be extended.
    Thank you for your support!
  • Hello Guest, we are proud to now have our Wiki online that is completely compiled and written by our members. Feel free to browse our Jeep-CJ Wiki or click on any orange keyword when looking at posts in the forum.

PCV Connection Questions

PCV Connection Questions

Dolamite

Jeeper
Posts
180
Media
9
Thanks
0
Location
Michigan's Upper Peninsula
Vehicle(s)
1980 Jeep CJ5
258 I6
3.54 gears
AMC 20 Rear Diff (1 piece Axles w/Lokka)
Dana 30 Front Diff w/Lokka
Tremec T-176 4 speed Trans
Dana 300 transfer Case w/Twinstick
My CJ5 has a AMC 258 i6 / 4.2l with a 2-barrel Weber carb. I have no complaints about how the engine runs, but I noticed the PO only has one of the ports from the PCV connected to anything. The other port is left open.

Question #1: What should I connect the open port (circled in blue on the attached picture) of the PCV to?

Question #2: Should I install a breather on the rear opening in the valve cover (circled in red)? It currently has a rubber plug installed.

As I've stated earlier, everything runs great. I just don't want to cause any damage to the engine.

Thanks for the help!
 
Your PVC looks to be hooked up right the one in the back was a hose that ran to the air filter they probably pluged it when they went to a aftermarket air cleaner.
 
Your PVC looks to be hooked up right the one in the back was a hose that ran to the air filter they probably pluged it when they went to a aftermarket air cleaner.

Thank you mtnwhlr. So you think I should just leave it as it is? The port of the PCV that is open doesn't need to be connected to anything?

Appreciate your input!
 
The hose from the PVC should be hooked to the port at the base of the carb.
 
Dolamite, I would suggest installing a breather at the rear hole in the valve cover. This helps relieve the crankcase pressure from an old engine.
 
Dolamite, I would suggest installing a breather at the rear hole in the valve cover. This helps relieve the crankcase pressure from an old engine.

Adding a breather would probably prevent the dipstick from popping out and leaking oil, wouldn't it? Any downsides to a breather?
 
The biggest downside would be if you have to go in for emissions testing. Excessive blow by should get filtered out so deposits won't collect on your firewall. It pretty apparent that you have a lot of pressure in your CJs crankcase if you can blow out a dipstick.
 
Got it. Thanks Torxhead!
 

Jeep-CJ Donation Drive

Help support Jeep-CJ.com by making a contribution.

Help support Jeep-CJ.com by making a contribution.
Goal
$200.00
Earned
$0.00
This donation drive ends in
0 hours, 0 minutes, 0 seconds
  0.0%
Back
Top Bottom