My Willys 3A and 3B Community

3A, 3B, DJ Technical Knowledge Base => "Original"-- Technical Questions, Answers, Observations => Topic started by: 3aJeeper on June 20, 2011, 07:27:29 AM

Title: Vapor from breather - probably not good
Post by: 3aJeeper on June 20, 2011, 07:27:29 AM: After I run the F134 I notice that there is a wisp of vapor (steam??) escaping from the breather on top of the valve spring cover. It's not a lot, but if you look for it you can see it. I'm guessing this is moister where it shouldn't be. I'm hesitant to dig down into the engine but if that's what I need to do, then so be it. Mainly because I'm afraid that I'll find that the engine block is cracked and I need a new engine. ï¿½:(

Hopefully just needs a new head gasket. Does that sound plausible?

Also there is white-ish smoke out the back.

(http://img545.imageshack.us/img545/1958/breather1.jpg) (http://imageshack.us/photo/my-images/545/breather1.jpg/)
Title: Re: Vapor from breather - probably not good
Post by: Bob W on June 21, 2011, 06:44:16 AM: Quote
After I run the F134 I notice that there is a wisp of vapor (steam??) escaping from the breather on top of the valve spring cover. It's not a lot, but if you look for it you can see it. .............
Also there is white-ish smoke out the back.

If those are the only symptoms I would just drive it and see how it goes.
Title: Re: Vapor from breather - probably not good
Post by: Matto on June 22, 2011, 09:53:06 PM: You may want to check your PCV valve. You can take it apart to clean it out. Here is a link to the CJ3B site that describes the whole system. I had a problem with white foam building up under my oil fill cap. It turned out the previous owner had disconected and plugged the vacume line on the intake manifold to increase vacume to the wipers. I repaired that and cleaned the PCV valve and the problem went away.
http://www.film.queensu.ca/CJ3B/Tech/PCV.html
Title: Re: Vapor from breather - probably not good
Post by: Bob W on June 23, 2011, 05:41:22 AM: Looks like that engine may have a road draft tube instead of a PCV system. Either way it would be a good idea to check the crankcase venting system.
Title: Re: Vapor from breather - probably not good
Post by: 3aJeeper on June 23, 2011, 08:39:13 AM: Yes - I think it has the road draft tube. It's this thing here, correct?

(http://img4.imageshack.us/img4/4186/drafttube.jpg) (http://imageshack.us/photo/my-images/4/drafttube.jpg/)
Title: Re: Vapor from breather - probably not good
Post by: Bob W on June 23, 2011, 08:16:15 PM: Quote
Yes - I think it has the road draft tube. It's this thing here, correct?

Yep, that is a road draft tube. When the vehicle is moving the air flowing over the end of the tube causes a slight vacuum which pulls air in that filter on the valve cover, through the engine, and out the tube. It would be normal for some vapor to exit the filter on the valve cover when the vehicle is stationary since the air flow would be reversed (hot air rises). That engine probably came from a utility series vehicle, some of which did not use PCV systems.
Title: Re: Vapor from breather - probably not good
Post by: Gunslinger on June 27, 2011, 11:30:58 PM: You might want to check that cap to make sure that air can get through it easily, its a coallesing cap so its supposed to have a mesh screen in it to stop oil vapor from going out., yet it needs to let air in while driving in order to vent out the draft tube. if that is plugged you can get negative pressure in the crankcase and may lose oil out the draft tube. And when the engine shuts down it should breathe just the opposite way, up the draft tube and out the cap.