Smoke from valve cover breather - Pontiac GTO Forum
User Tag List

 
LinkBack Thread Tools Display Modes
post #1 of 6 (permalink) Old 09-28-2018, 05:11 PM Thread Starter
 
Ohio66GTO's Avatar
 
Join Date: May 2014
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 14 Post(s)
Smoke from valve cover breather

Got the GTO running after swapping out the 455 with a 428. Took for about a mile ride and when I got back I noticed smoke coming from the breather. Let it sit for a couple days and took it around the development which is a shorter ride and no smoke. Sat a couple days and went the same route as the first time, about a mile, and it’s smoking again. Did some research and sounds like it’s blow-by from a bad PCV valve, or worn rings. I shook the PCV valve and it rattles. From what I’ve read that’s good. My question is, is there another way to tell if the PCV valve is good or bad other then rattling? Are there better PCV valves then others? Not sure what brand mine is. Lastly, is there anything else besides the PCV valve or worn rings that could be causing this? Guy I bought the engine from said it was rebuilt recently with very low mileage. Said less then 3000. I kind of question that but it does look fairly new. Had him run it on his stand for about 20-30 minuets without any issues. It’s a 68 block rebuilt to stock he said.
Ohio66GTO is offline  
Sponsored Links
Advertisement
 
post #2 of 6 (permalink) Old 09-29-2018, 04:58 AM
 
deanhickey's Avatar
 
Join Date: Apr 2015
Location: London and Maine
Posts: 149
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 38 Post(s)
Garage
I would start by replacing the PCV valve, as they are inexpensive. If that is doesn't work on to a compression test. There are more knowledgeable people here than myself who are able to give better advise. How much oil pressure do you have on the engine and this may seem like a silly question but how much oil is in the engine? overfilling may be something to look at. good luck.
deanhickey is offline  
post #3 of 6 (permalink) Old 09-29-2018, 09:09 AM
Super Moderator
 
BearGFR's Avatar
 
Join Date: Aug 2008
Location: Springtown, TX
Posts: 5,730
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 122 Post(s)
Garage
Do you have both parts of the PCV system installed and working? The hose with the valve attached is only half of the system. The other half should be a tube/hose from one of the rocker covers that usually attaches to the air cleaner and has a filter at that point.

Like in the attached diagram.


Bear
Attached Thumbnails
Click image for larger version

Name:	0900c1528004def9.gif
Views:	93
Size:	24.2 KB
ID:	115639  

BearGFR
Springtown, TEXAS
BearGFR is offline  
 
post #4 of 6 (permalink) Old 09-29-2018, 03:37 PM Thread Starter
 
Ohio66GTO's Avatar
 
Join Date: May 2014
Posts: 39
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 14 Post(s)
Thanks for the reply’s guys. I checked the oil level and it was right where it should be. Replaced the PCV valve and it still smokes.
I looked at your picture and I don’t have the hose that goes to the air cleaner. I probably should’ve been more specific when I said rebuilt to stock. What I meant by that was crank,cam. Basically the internals. It doesn’t have a stock air cleaner. The intake is an Edelbrock Torker 2 with a Weber 750 carb. Not sure if it not being stock changes your thinking with that diagram. There is a breather on the passenger side valve cover and the oil filler cap on the drivers side is vented. Here are pictures of how the PCV valve is attached and the breathers on the valve covers. Also a picture of the air cleaner I’m using.
Oil pressure @Startup @idle is 60psi
Oil pressure @180 degrees @idle is 40 psi
Oil pressure @2500-3000 rpm is 65psi
Attached Thumbnails
Click image for larger version

Name:	A7D11298-5C7A-46E9-AB90-54150B46D3FB_1538252981857.jpg
Views:	69
Size:	1.23 MB
ID:	115645   Click image for larger version

Name:	CEB402F4-061E-4B86-A87F-DAF0947C6654_1538253103635.jpg
Views:	66
Size:	1.05 MB
ID:	115647   Click image for larger version

Name:	974BDFAA-6A14-4E34-95BA-D4C2E5DEA457_1538253399558.jpg
Views:	63
Size:	1.17 MB
ID:	115649  
Ohio66GTO is offline  
post #5 of 6 (permalink) Old 09-29-2018, 03:48 PM
 
My65goat's Avatar
 
Join Date: Jul 2017
Posts: 75
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Get a leak down tester. It will show if you have bad rings.

A leak down test is one of the most definitive tests.

Good luck, hopefully it's not a internal problem. ..
My65goat is offline  
post #6 of 6 (permalink) Old 09-30-2018, 01:31 PM
64-67 Expert
 
geeteeohguy's Avatar
 
Join Date: Feb 2008
Location: Fresno, California
Posts: 8,457
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 98 Post(s)
Quote:
Originally Posted by My65goat View Post
Get a leak down tester. It will show if you have bad rings.

A leak down test is one of the most definitive tests.

Good luck, hopefully it's not a internal problem. ..
This^^^. The only accurate way of determining internal engine condition. If you have more than 25% leakdown, and the air is coming from the breathers, it's piston ring wear/fitment.
geeteeohguy is offline  
Sponsored Links
Advertisement
 
Reply

  Pontiac GTO Forum > The 1964-1974 Pontiac Tempest, Lemans & GTO > 1964-1974 Tempest, LeMans & GTO Engine Tuning and High Performance

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Pontiac GTO Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Valve Cover Breather Cap Leaks Oil at WOT MaL 1964-1974 Tempest, Lemans & GTO Complete Engine Compartment Discussion 5 03-10-2017 09:17 AM
smoke out of breather! Seol21 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 8 02-03-2013 05:03 PM
Blue smoke, oil puddle. Valve stem gasket? KingJacobo 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 14 01-15-2012 02:54 PM
Intake Breather Hose? SleeperGoat Intake and Exhaust Discussions 5 11-17-2011 01:06 PM
where to buy oem breather xconcepts 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 7 01-02-2011 08:07 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome