mazda 626 - blowing white smoke when cold

[lowrida56]

I just replaced the headgasket and fitted a reconditiond head on my girlfriends car, it was fine for a couple of days but now every time you start a LOT of white smoke comes out of the exhaust until the car has warmed up for about 5 minutes.

does anybody have any idea what this could be?

[Stupa]

Unburnt fuel, I got a heao if white smoke pouring out the back of my vs when 2 cylenders werent firing

[Not_An_Abba_Fan]

Is it running rough while the white smoke is coming out? Does the white smoke evaporate pretty quickly or does it hang around and smell fuelly?

[VZTHUNDER]

can be either fuel or evaporation

[andyman]

i thought fuel was black

[Stupa]

Diesel is black

[andyman]

Diesel is black

i know that, what is black smoke from a petrol engine than, clapped out engine?

[The Darkness]

black smoke is fkd o rings i think. white smoke is either oil burning or unburnt fuel{not sure about the latter}

[adam69]

Black is fuel,blue is oil and sometimes it is white.Sound like water evap.Keep an eye on all of the levels and see what you are loosing.
My sister had an 91 626 and after an oil change it was doing something similar and it was oil burning on start up.

[adam69]

if it was oil burning it would only be for a few seconds,ive never seen a car burn oil for 5 min and then stop.

[The Darkness]

so whats moisture/water in exhaust mean?

[samuels]

i know that, what is black smoke from a petrol engine than, clapped out engine?

black is unburnt fuel...diesel/petrol
white is water,and can be oil...have you re-tensioned the head? or is it the new fang dangle monotorque,no re-tensioning required,another possibilty is a crack into cylinder wall,allowing water to be evaporated,hence the white smoke,BUT then again,it may well be just normal,if everything else checks out
blue is oil being burnt....

[samuels]

if it was oil burning it would only be for a few seconds,ive never seen a car burn oil for 5 min and then stop.

i have...

[Not_An_Abba_Fan]

if it was oil burning it would only be for a few seconds,ive never seen a car burn oil for 5 min and then stop.

Smoking for a few seconds is valve stem seals, if it keeps going then it would be rings. Oil smoke that is.

White smoke could just be condensation. It means the cat is working.

Also it would be nice to reply to some of these suggestions.

[lowrida56]

Is it running rough while the white smoke is coming out? Does the white smoke evaporate pretty quickly or does it hang around and smell fuelly?

it runs fine when the smoke is coming out. ill smell it tonite and see what it smeels like.

Unburnt fuel, I got a heao if white smoke pouring out the back of my vs when 2 cylenders werent firing

its also got an idleing problem that starting the same time as the car overheated and did the head gasket, maybe there related? after warm up it hunts at idle realy badly (idles at between 1500 and 2000rpm when in neutral or park) but the problem will somtimes go away and it will idle normally at around 800rpm.
how can i check for unburnt fuel?

Smoking for a few seconds is valve stem seals, if it keeps going then it would be rings. Oil smoke that is.

if the valve stem seals were leakin a fair bit of oil over nite could it take a few minutes to burn up then? or would it go pretty quickly?

[lowrida56]

Smoking for a few seconds is valve stem seals, if it keeps going then it would be rings. Oil smoke that is.

White smoke could just be condensation. It means the cat is working.

Also it would be nice to reply to some of these suggestions.

its not condensation the whole street fills with smoke which you cant see thrue, it looks like ive just done a huge burn out.

black is unburnt fuel...diesel/petrol
white is water,and can be oil...have you re-tensioned the head? or is it the new fang dangle monotorque,no re-tensioning required,another possibilty is a crack into cylinder wall,allowing water to be evaporated,hence the white smoke,BUT then again,it may well be just normal,if everything else checks out
blue is oil being burnt....

i havent retentiond the head yet as it said to do it after 800km, but i will tension it tonite.

[samuels]

its not condensation the whole street fills with smoke which you cant see thrue, it looks like ive just done a huge burn out.



i havent retentiond the head yet as it said to do it after 800km, but i will tension it tonite.

let us know if it smells oily...from what you have described,i'd say you have cooked your oil control rings(especially if you said you overheated it a fair bit)....but don't hold me to that,because you said it only does it for what a couple of minutes?
another thing is....a loose intake manifold,if it's a carby job,loose base..all of which suck in air,and can cause engine hunting....

[Not_An_Abba_Fan]

If it is a loose intake manifold, it could be that it is enough to have a vacuum leak and maybe sucking a bit of water in if it is the model that the coolant runs through the manifold. When it warms up, everything expands and the leak stops.

[jdd]

Auto transmission fluid also produces thick white smoke when burnt similar to what’s been described.
If it’s and auto, check to see if the are any vacumn lines from the auto into the inlet manifold. If so clamp these off next time before starting it when cold.
It could be that there’s a vacumn controlled solenoid which has a leak and is letting transmission fluid into the inlet manifold.

[lowrida56]

Auto transmission fluid also produces thick white smoke when burnt similar to what’s been described.
If it’s and auto, check to see if the are any vacumn lines from the auto into the inlet manifold. If so clamp these off next time before starting it when cold.
It could be that there’s a vacumn controlled solenoid which has a leak and is letting transmission fluid into the inlet manifold.

ye ill try that on the weekend.