Jump to content


Photo

Blowing smoke at idle


  • Please log in to reply
33 replies to this topic

#1 Muzzy

Muzzy

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 639 posts
  • Name:Brian
  • Location:Dubbo
  • Car:LH Gran pa special
  • Joined: 29-October 13

Posted 25 October 2016 - 06:25 PM

Hi All ,after some suggestions , please read what I have done and then offer up

#. engine gives puff on start up ( sometimes)
# if you ildle when hot smoke is visible from exhaust after. Few minutes
#. O valve seals have been replaced twice
#. No oil thru PVC , this has been checked
#. New valves and valve guides

engine package has done about 1200 k

The head was used in another engine , apart from valve change didn't blow smoke

The only change I can pick is the engine run a lot of oil pressure, std JP pump, from 1000 rpm up steady 60 PSI and about 40 at IDLE , hot,
Could I be getting to much oil under the cover and drowning the valves?
The oil consumption isn't bad, more annoying @ 500ml per 1000 k

Open to ideas!

Sorry the other point it's running 20-50 now , was on 15-40 no difference!

#2 myss427

myss427

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 1,303 posts
  • Location:Canberra
  • Car:427 hatch, CV8 Monaro, Ve SSV ute. Was part owner A9X sedan until he sold it without telling me!
  • Joined: 17-November 05
Garage View Garage

Posted 25 October 2016 - 07:51 PM

Can be a shit load of things, could be guides or worn valve, running rich, worn rings, bad hone, bad PVC valve, its all checking and process of elimination. I know you have said you have replaced a lot of this, but it only take one cylinder or valve guide to cause the problem and machinists can make mistakes. Oil pressure has nothing to do with burning oil.



#3 RallyRed

RallyRed

    Oh My, Don't you post alot

  • Members
  • PipPipPipPipPipPipPip
  • 4,304 posts
  • Name:Col
  • Location:NSW
  • Car:LC GTR
  • Joined: 02-October 11

Posted 25 October 2016 - 08:28 PM

how hard to change the pump to a normal one Brian?....your oil pressure numbers are impressive, but do seem high?



#4 Redslur

Redslur

    Lotsa Posts!

  • Members
  • PipPipPipPipPipPip
  • 2,727 posts
  • Name:Gerry
  • Location:NSW
  • Car:LH 4 door 355
  • Joined: 08-November 05

Posted 25 October 2016 - 08:43 PM

Take it for a good long hard drive and see if it improves, Things just may need beding in a little. Fouled plugs is normally a good indication if things aren't right.



#5 Muzzy

Muzzy

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 639 posts
  • Name:Brian
  • Location:Dubbo
  • Car:LH Gran pa special
  • Joined: 29-October 13

Posted 25 October 2016 - 08:47 PM

Take it for a good long hard drive and see if it improves, Things just may need beding in a little. Fouled plugs is normally a good indication if things aren't right.


Yer it will get a good run from Dubbo to ACT in a couple of weeks, after that I might play with the oil pressure , I reckon there is too much being sprayed around

Can be a shit load of things, could be guides or worn valve, running rich, worn rings, bad hone, bad PVC valve, its all checking and process of elimination. I know you have said you have replaced a lot of this, but it only take one cylinder or valve guide to cause the problem and machinists can make mistakes. Oil pressure has nothing to do with burning oil.


The oil pressure comment is based on to much being sprayed around under the cover,

#6 LXCHEV

LXCHEV

    Lotsa Posts!

  • Members
  • PipPipPipPipPipPip
  • 2,783 posts
  • Name:Brett
  • Location:Melbourne
  • Car:'76 LX - 383 Chev
  • Joined: 08-November 05

Posted 25 October 2016 - 09:40 PM

A leak-down test may help to pinpoint any issues. Worth considering.

#7 warrenm

warrenm

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 1,764 posts
  • Location:Central West NSW
  • Car:1972 LJ Torana
  • Joined: 08-November 05
Garage View Garage

Posted 25 October 2016 - 11:28 PM

Oil pressure isn't your problem, as has been mentioned already.



#8 LC-GTR-1969

LC-GTR-1969

    Shed tinkerer

  • Members
  • PipPipPipPipPip
  • 926 posts
  • Location:New South Wales
  • Car:Which one?
  • Joined: 09-March 14
Garage View Garage

Posted 26 October 2016 - 03:53 PM

Ive had a similar experience, new valve seals yada yada, engine blowing some smoke puffs which didnt really make sense... turned out in my case it was a dodgy valve guide... different engine but similar symptoms


Edited by LC-GTR-1969, 26 October 2016 - 03:53 PM.


#9 Muzzy

Muzzy

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 639 posts
  • Name:Brian
  • Location:Dubbo
  • Car:LH Gran pa special
  • Joined: 29-October 13

Posted 26 October 2016 - 05:11 PM

Ive had a similar experience, new valve seals yada yada, engine blowing some smoke puffs which didnt really make sense... turned out in my case it was a dodgy valve guide... different engine but similar symptoms


The head did have new inlet guides fitted,

#10 LC-GTR-1969

LC-GTR-1969

    Shed tinkerer

  • Members
  • PipPipPipPipPip
  • 926 posts
  • Location:New South Wales
  • Car:Which one?
  • Joined: 09-March 14
Garage View Garage

Posted 26 October 2016 - 06:19 PM

The head did have new inlet guides fitted,

 

It may not be the issue if they have been replace, but as a side note, I have seen some serious errors from some good/great reconditioners before. Ive even had a block milled 10mm past the 0 deck height. No idea how this happened but it did. I have also had cylinders at 8-10thou beyond what they where suppose to be. sorry for the side track, just venting lol



#11 Agent 34

Agent 34

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 2,182 posts
  • Name:grant
  • Location:the man cave
  • Car:" Lucky " the lime green metalic 72 GTR" and " Rocket the NOT so GTR or XU1" 73 S Pack
  • Joined: 17-May 10
Garage View Garage

Posted 26 October 2016 - 07:32 PM

Its probably a piss off than anything. there is only two sources of oil into cylinder 1) valves 2) rings.

 

I'd take it for a good hard run and drive it like you stole it get the temp up, - it has heaps of pressure to the crank and bearings and it's done 1200 klms so there is probably no fear there of giving it a canning.

 

If i remember its only running a two barrel so over fueling to the cylinders would not probably be an issue.

 

it's just weird that after 2 minutes the smoke comes out the back - 

 

why don't you post a video of the situation which may help diagnose or quantify.

 

I don't think as waz said it's an oil pressure issue.

 

G



#12 Macca97

Macca97

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 794 posts
  • Name:Danny
  • Location:Mid North Coast, NSW
  • Car:HJ Ute, Hz prem Wagon, HG Ute,
  • Joined: 03-September 12
Garage View Garage

Posted 27 October 2016 - 05:25 PM

mine does this every time, as ive left the exhaust valve stem seals off, also found it if my idle got to low, (below 600) it would blow abit after, im not worried, different brand off oil can increase consumption aswell, mine drinks atlantic 20w50, (brand at work) but doesnt use a drop of gulf western 20w50



#13 v6 torana

v6 torana

    Forum Fan

  • Members
  • PipPipPipPip
  • 281 posts
  • Location:NSW
  • Joined: 17-January 12

Posted 27 October 2016 - 05:50 PM

Are you running a trimatic ? if so, have you checked for a leaking modulator ?



#14 Muzzy

Muzzy

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 639 posts
  • Name:Brian
  • Location:Dubbo
  • Car:LH Gran pa special
  • Joined: 29-October 13

Posted 27 October 2016 - 06:35 PM

Are you running a trimatic ? if so, have you checked for a leaking modulator ?


No manual

#15 Muzzy

Muzzy

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 639 posts
  • Name:Brian
  • Location:Dubbo
  • Car:LH Gran pa special
  • Joined: 29-October 13

Posted 27 October 2016 - 06:38 PM

mine does this every time, as ive left the exhaust valve stem seals off, also found it if my idle got to low, (below 600) it would blow abit after, im not worried, different brand off oil can increase consumption aswell, mine drinks atlantic 20w50, (brand at work) but doesnt use a drop of gulf western 20w50


Head was rebuilt, new O rings on exhaust, new guides and valves on inlet, it's running GW 20-50, idles at 725-750

#16 Agent 34

Agent 34

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 2,182 posts
  • Name:grant
  • Location:the man cave
  • Car:" Lucky " the lime green metalic 72 GTR" and " Rocket the NOT so GTR or XU1" 73 S Pack
  • Joined: 17-May 10
Garage View Garage

Posted 27 October 2016 - 07:39 PM

brian - not may hills at dubbo - maybe the rings needs a good hard load up on a dyno ? - if there is one in town.



brian - not may hills at dubbo - maybe the rings needs a good hard load up on a dyno ? - if there is one in town.



#17 S pack

S pack

    Rivet Counter

  • Members
  • PipPipPipPipPipPipPip
  • 10,785 posts
  • Name:Dave
  • Location:Luggage Point
  • Car:73 LJ
  • Joined: 25-January 10

Posted 27 October 2016 - 08:37 PM

Head was rebuilt, new O rings on exhaust, new guides and valves on inlet, it's running GW 20-50, idles at 725-750

Oil is more likely to be sucked in past the inlet valves than the exhaust valves when the engine is running.



#18 Muzzy

Muzzy

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 639 posts
  • Name:Brian
  • Location:Dubbo
  • Car:LH Gran pa special
  • Joined: 29-October 13

Posted 18 April 2017 - 05:55 PM

Hi here is an update
As mentioned valve stem seals have been changed, after doing a heap of tests, I isolated the smoke to 2 cylinders, here is the valve guide boss on one of inlets, whilst I have heard some say this won't cause oil consumption I can assure you it drinks oils big time on this cylinder . Now my question open for suggestions on the repair method. The guy who installed the valve guides doesn't want to know about it!

Attached Files



#19 Bomber Watson

Bomber Watson

    Not nearly as smart as Lazarus

  • Members
  • PipPipPipPipPipPipPip
  • 20,370 posts
  • Name:DJ
  • Location:Rockhampton, the exact center of my own TINY universe. Also the home of the worlds longest location.
  • Car:Mixed fleet of Taxi's and hair dresser mobiles.
  • Joined: 07-November 05

Posted 18 April 2017 - 06:18 PM

Typical 12 port issue. 

It will continue down into the valve seat if you dont take care of it. 

Metal stitch it maybe?



#20 LC-GTR-1969

LC-GTR-1969

    Shed tinkerer

  • Members
  • PipPipPipPipPip
  • 926 posts
  • Location:New South Wales
  • Car:Which one?
  • Joined: 09-March 14
Garage View Garage

Posted 19 April 2017 - 08:04 PM



Metal stitch it maybe?

 

+1



#21 TK383

TK383

    Forum Participant

  • Members
  • PipPip
  • 49 posts
  • Name:Tony
  • Location:SA
  • Car:Blue one
  • Joined: 30-March 11

Posted 21 April 2017 - 03:42 PM

That guide has a thinwall iron guide fitted, the crack is just cosmetic - it's fine, no problem there.

If it's that guide causing smoke then it's a guide clearance issue or a stem seal issue (or both).



#22 Muzzy

Muzzy

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 639 posts
  • Name:Brian
  • Location:Dubbo
  • Car:LH Gran pa special
  • Joined: 29-October 13

Posted 21 April 2017 - 03:49 PM

That guide has a thinwall iron guide fitted, the crack is just cosmetic - it's fine, no problem there.
If it's that guide causing smoke then it's a guide clearance issue or a stem seal issue (or both).


I have chasing this issue for a while, each inlet has a Chev umbrella seal plus the O ring seal, plus new valves and new guides fitted, the engine is using oil in 2 cylinders and these 2 cylinders are cracked on the boss. Whilst I don't disagree with you I'm at the end of my ideas list LOL

#23 lawn bowls

lawn bowls

    Forum Participant

  • Members
  • PipPip
  • 34 posts
  • Location:queensland
  • Car:72 lj 4 door
  • Joined: 17-March 17

Posted 21 April 2017 - 08:55 PM

what colour is the smoke?check your brake booster hose that goes to the intake manifold,it could be leaking brake fluid?



#24 grumpy xu1

grumpy xu1

    Forum Fixture

  • Members
  • PipPipPipPipPip
  • 1,154 posts
  • Name:Gary
  • Location:Queensland
  • Car:lj xu1
  • Joined: 01-February 10

Posted 21 April 2017 - 10:25 PM

Are you serious, brake fluid ??????? I think you would be meaning oil from a pcv actually !

#25 lawn bowls

lawn bowls

    Forum Participant

  • Members
  • PipPip
  • 34 posts
  • Location:queensland
  • Car:72 lj 4 door
  • Joined: 17-March 17

Posted 21 April 2017 - 11:06 PM

where do you get vacuum for your brakes?from the intake manifold.if its a white smoke it could be brake fluid seeping into the intake from the master cylinder.






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users