Notice: We request that you don't just set up a new account at this time if you are a previous user.
If you used to be one of our moderators, please feel free to reach out to Chris via the facebook Outerlimits4x4 group and he will get you set back up with access should he need you.
Recovery:If you cannot access your old email address and don't remember your password, please click here to log a change of email address so you can do a password reset.

smoke from under rocker cover

General Tech Talk

Moderators: toaddog, TWISTY, V8Patrol, Moderators

Post Reply
Posts: 12
Joined: Sat Sep 26, 2009 12:40 pm
Location: Sydney

smoke from under rocker cover

Post by karol »

hi
yesterday after a while of running the engine, i opened the oil filler cup and there was bit of smoke coming from the inside. then i disconnected the rubber hose, that goes from the rocker cover into the air filter reved the engine and there was again smoke coming out. more as it reved higher. what does it mean? is something horrible about happen to my engine? its patrol with tb42 carby
cheers
Posts: 280
Joined: Tue Feb 16, 2010 1:21 pm
Location: Werribee

Re: smoke from under rocker cover

Post by MrGrim »

it could be all normal as a little blow by ..
depending on the ks the motor has done
this aslo would be normal on an old engine " worn rings "
to settle your nerves just do a compresion test if thats all good
then forget about it
71 fj40 front shackle reversal +3" , 55 rear springs +3", 35 15.5 claws , 60 diff's 4wheel disc's , SOON TO BE WINDSOR V8 + 5 speed
74 fj40 stock but very clean
84 bj40 3b stock and unloved
Posts: 3099
Joined: Wed Dec 11, 2002 10:55 am
Location: Central Queensland

Re: smoke from under rocker cover

Post by BundyRumandCoke »

As said, some smoke can be normal. The job of the rubber hose, the PCV (Positive Crankcase Ventilation) system is to remove that smoke, and associated gasses, and pass them into the inlet manifold, where they are burnt in the normal combustion process. Worn rings or valve stem seals could be the culprit. How many Ks on the motor?
Mud makes excellent toothpaste.
Posts: 470
Joined: Wed Jan 24, 2007 12:21 pm
Location: Australia

Re: smoke from under rocker cover

Post by 351ciofgrunt »

It's normal, don't worry about it
GQ Patrol Wagon, 6 point roll cage
351 cleveland, CHI heads, solid cam, Funnelweb single plane, 750 HP DP
Posts: 12
Joined: Sat Sep 26, 2009 12:40 pm
Location: Sydney

Re: smoke from under rocker cover

Post by karol »

the engine has done 300 000 km however I'm not sure how genuine they are. can i eventually somehow block the whole smoke recirculation off?
Posts: 3038
Joined: Thu Aug 05, 2004 10:06 pm
Location: VIC

Re: smoke from under rocker cover

Post by dogbreath_48 »

karol wrote:the engine has done 300 000 km however I'm not sure how genuine they are. can i eventually somehow block the whole smoke recirculation off?
No, but you could run a catch can to catch some of the smoke (oil vapor) before it gets into the intake. But unless it's excessive and causing other problems there's no reason to.

Blocking the rocker cover breather off is a big no-no and having it vent into the atmosphere is a legal no-no.
Tetanus rolling on 37's
Posts: 12
Joined: Sat Sep 26, 2009 12:40 pm
Location: Sydney

Re: smoke from under rocker cover

Post by karol »

apart from not being exactly legal, would it work if i plug those two hoses and put two of those small tiny supercheap auto air-filters on the rockercover? im just worried that all that smoke can not be good for the carby
Posts: 280
Joined: Tue Feb 16, 2010 1:21 pm
Location: Werribee

Re: smoke from under rocker cover

Post by MrGrim »

karol wrote:apart from not being exactly legal, would it work if i plug those two hoses and put two of those small tiny supercheap auto air-filters on the rockercover? im just worried that all that smoke can not be good for the carby
its no problem at all for it unless its making the throut of the carb realy oily then fix with a catch can ..a breather as you sudjested will also suck water if you cross a creek ect with the sudden cold change
71 fj40 front shackle reversal +3" , 55 rear springs +3", 35 15.5 claws , 60 diff's 4wheel disc's , SOON TO BE WINDSOR V8 + 5 speed
74 fj40 stock but very clean
84 bj40 3b stock and unloved
Posts: 137
Joined: Tue Jun 03, 2008 6:18 pm
Location: Sydney, Australia

Re: smoke from under rocker cover

Post by McLarryBob »

A bit of smoke from the engine is normal and that is exacly what the PCV is there to get rid of.
You definatly don't want to block off the PCV because all those gasses have to go somewhere. If you do block it off the gasses will build up in the engine and will have to escape somewhere and that somewhere will be your oldest/weakest oil seals. And you don't want that.

http://www.youtube.com/watch?v=8-ymU7ET ... re=related" onclick="window.open(this.href);return false; This is a cool vid showing what happens in the engine and how much smoke/oil vapor can be produced
Post Reply

Who is online

Users browsing this forum: No registered users and 0 guests