350 Problems - Team Camaro Tech
Tech 2000 Our previous General Forum
Replies ONLY - no new topics.

 
LinkBack Thread Tools Display Modes
post #1 of 6 (permalink) Old Jul 6th, 00, 04:39 PM Thread Starter
 
Join Date: Jul 1999
Location: Rising Sun, MD
Posts: 6
Question

About a week ago the 350 in my 69 started to blow blue smoke. I took out the spark plugs and the plug in cylinder 3 was fouled with oil... badly. This was the only cylinder like this. Did a compression test and all were consistant, even cylinder 3. Any suggestion on what may cause this?
ANDREW is offline  
Sponsored Links
Advertisement
 
post #2 of 6 (permalink) Old Jul 6th, 00, 04:56 PM
Senior Tech
 
Join Date: Dec 1999
Location: Big D little a-l-l-a-s
Posts: 523
Post

My first thought is a bad valve guide or a seal on that number three cylinder. If it were a bad ring on the #3 cylinder, it would probably would smoke ALL the time.

You should do the compression check with the engine hot because it makes the oil thinner and the problem will show up more readily than if the engine is tested cold.

You could remove the spark plug and squirt some oil down into the cylinder and if the compression jumps up on #3 then more than likey it is a piston ring problem instead of a head related problem.

sr71bb is offline  
post #3 of 6 (permalink) Old Jul 6th, 00, 05:02 PM
Senior Tech
 
Join Date: Jun 2000
Location: Las Vegas, NV
Posts: 144
Thumbs up

Sounds to me like a valve stem seal or worn guide. If the compression test shows #3 is holding pressure, then the valve and seat should still be good. You're probably just sucking oil in past the intake valve stem/guide. Minor repair once the head's off but I'M not aware of anyway to repair it while still installed on the engine. If anyone knows a way I'm sure we'd BOTH like to know about it.

Does it continuously blow the blue smoke, or does it only happen on initial start-up then go away?
POP D TOP is offline  
 
post #4 of 6 (permalink) Old Jul 6th, 00, 05:08 PM
Moderator
David Pozzi
 
davidpozzi's Avatar
 
Join Date: Nov 1999
Location: Central California, USA
Posts: 10,064
Post

I can think of a couple.
Most likely it's an intake valve seal. Which is usually a rubber O ring between the intake valve stem and the retainer. Sometimes they can break and fall out.

Some times a loose piece of valve cover gasket can plug a drain back hole and flood the valve area with oil. But this usually causes oil fouling at the rear of the engine as that is the low end of the engine.

The rings or ring lands can break, If it's a ring land it might not show up on a compression test.

The intake manifold can leak oil from the valley area into the port. This would be accompanied by a miss and spitting back while idling.

If a wrist pin came loose it might contact the cylinder wall and put a groove in it leaking oil, but compression would be down too.

Most likely it's the valve seal. If you have the type that goes over the valve guide, it could be worn out.

Either way, you can put air into the spark plug hole and change the seal and add a push on seal over the valve guide. The intake side is the one to worry about.
David

------------------
Check my web page for suspension info:
David's Homepage
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer
davidpozzi is offline  
post #5 of 6 (permalink) Old Jul 7th, 00, 03:31 PM
Senior Tech
 
Join Date: Aug 1999
Location: Ontario, Canada
Posts: 564
Post

Same thing happened to a friend of mine with his Corvette, It was his aluminum Intake that was bad, The one cylinder always fouled up on his recent rebuild, It was one of the inside cylinders. It was sucking an oil mist from from the lifter valley, it was most noticable when he backed off the throttle.He went through all of the trial and error replaced heads, rings etc. only to have the same problem , replaced the intake and no more cloud of blue.
Rob.Canada is offline  
post #6 of 6 (permalink) Old Jul 7th, 00, 08:41 PM
Tech Team
 
Join Date: May 2000
Posts: 31
Post

Like they said check the intake.A friend of mines 454 chevelle started that.When I started to take the intake off,I noticed the bolts were very very loose.Turns out he didnt tighten them good because he didnt want to scar up his factory aluminum intake.Plus he had cheap rebuilder gaskets.FelPro gaskets and good tightening fixed it.Its a good a guess as any.Good luck.
Boomhauer is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech 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.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not 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