[honks]

i drive my sierra 4 days a week for about 70kms each trip but every time i start it up after it sits for a while i spray paint everything behind me in soot i understand that condensation could build up if not driven regularly and parked outside but my zook is garaged at night and driven pretty regularly.And it isn't loosing any coolant.just curious what could cause this.

[lordfury007]

oil?

blue/black smoke indicates oil, white smoke (steam) indicates water/coolant...

To me it sounds somewhat serious, but I'm not a grease monkey by a long shot.

[royce]

do you rev it a few times when you start it? jsut let it idle and it wont spit soot, you could also have a build up of soot in there getting blown out when its cold

[honks]

wasn't realy the soot coming out that bothers me but what appears to be water dripping off the end of the exhaust pipe

[royce]

water is a by product of a catalytic convertor

[Built4thrashing]

PLus there is some moisture in modern fuels. Some servos have been know to water down their fuel too. i get this all the time but nothing is wrong.


B4T

[want33s]

Built4thrashing wrote:

PLus there is some moisture in modern fuels. Some servos have been know to water down their fuel too. i get this all the time but nothing is wrong.


B4T

That's the biggest crock of shit...
Petrol and water WILL NOT mix.

[MacDaddy]

honks wrote:

i drive my sierra 4 days a week for about 70kms each trip but every time i start it up after it sits for a while i spray paint everything behind me in soot i understand that condensation could build up if not driven regularly and parked outside but my zook is garaged at night and driven pretty regularly.And it isn't loosing any coolant.just curious what could cause this.

I dont know much about Ipswich weather, but is it still pretty cold, and or rainy over there ?
I Would say weather plays a fairly big part in how much moisture will be coming out your exhaust, as the engine does suck in moisture out of the air... it should all but disappear in the hotter, drier weather... but if all the engine levels are fine, i say you got no problems...

[Built4thrashing]

Ive had new fuel with a layer of water in it. fresh from a jerry into a parts cleaner and it deffinately had water in it and it wasnt from the jerry can.


B4T

[royce]

1st of all, dont use petrol in a parts cleaner, you, like others before you will die

it doesnt mix, it cant mix, the pickups in the underground tanks will usually allow some few hundred litres of water to gather on the bottom before it can hit the pickup and water sits on the bottom of fuel so how did you see the layer?

[Built4thrashing]

we were washing parts in a large oil drain tub. poured about 5ltrs of fuel into it and it didnt look right. mixed it all up and put a sample in a glass jar and let it seperate. totally clear water in the bottom and a yellowish petrol on top. deffinately looked like water and didnt burn. was from a supermaket brand servo starting with S.


B4T

[TZAR]

all hydrocarbons have a specific gravity of around .93
water has a specific gravity of 1

this means water is heavier and sinks

This is why the gulf of mexico has oil on top of the water and not mixed up in it.

[honks]

cool well i will have to c what happens when the weather warms up in relation to the cat converter response could my cat be stuffed and this be the problem

[laurie]

i also spray paint the ground under my exhaust pipe with wet black spots of soot most times i start up from cold. also grey black smoke one out of 10 times or so. valve stem seals?
it goes away within a few seconds i also use no coolant
(well corrosion inhibiter at the moment) or much oil.
it blows very in frequent grey black smoke after coasting down a long hill using engine braking ie go down same hill 50 times see smoke once.
i have no cat on my car .
major tunes and a carb rebuild or a long drive have not made it go away
i have decided to ignore it for now.

[PJ.zook]

My zook and all my mates zooks splurt black soot onto the ground at startup, its not much of a concern.

[Llewellyn92]

royce wrote:

water is a by product of a catalytic convertor

sorry royce but that is incorrect, water is one of the products of the combustion of the fuel itself, dont you remember your ol chemistry lessons at school

[royce]

Llewellyn92 wrote:

royce wrote:

water is a by product of a catalytic convertor

sorry royce but that is incorrect, water is one of the products of the combustion of the fuel itself, dont you remember your ol chemistry lessons at school

Orly?

http://en.wikipedia.org/wiki/Catalytic_converter

Quote:

Two-way

A two-way catalytic converter has two simultaneous tasks:

1. Oxidation of carbon monoxide to carbon dioxide: 2CO + O2 ? 2CO2
2. Oxidation of unburnt hydrocarbons (unburnt and partially-burnt fuel) to carbon dioxide and water: CxH2x+2 + [(3x+1)/2] O2 ? xCO2 + (x+1)H2O (a combustion reaction)

This type of catalytic converter is widely used on diesel engines to reduce hydrocarbon and carbon monoxide emissions. They were also used on spark ignition (gasoline) engines in USA market automobiles through 1981, when the two-way converter's inability to control NOx led to its supersession by three-way converters.
Three-way

Since 1981, three-way catalytic converters have been used in vehicle emission control systems in North America and many other countries on roadgoing vehicles. A three-way catalytic converter has three simultaneous tasks:

1. Reduction of nitrogen oxides to nitrogen and oxygen: 2NOx ? xO2 + N2
2. Oxidation of carbon monoxide to carbon dioxide: 2CO + O2 ? 2CO2
3. Oxidation of unburnt hydrocarbons (HC) to carbon dioxide and water: CxH2x+2 + [(3x+1)/2]O2 ? xCO2 + (x+1)H2O

These three reactions occur most efficiently when the catalytic converter receives exhaust from an engine running slightly above the stoichiometric point. This point is between 14.6 and 14.8 parts air to 1 part fuel, by weight, for gasoline. The ratio for LPG, natural gas and ethanol fuels is slightly different, requiring modified fuel system settings when using those fuels. Generally, engines fitted with 3-way catalytic converters are equipped with a computerized closed-loop feedback fuel injection system employing one or more oxygen sensors, though early in the deployment of 3-way converters, carburetors equipped for feedback mixture control were used. While a 3-way catalyst can be used in an open-loop system, NOx reduction efficiency is low. Within a narrow fuel/air ratio band surrounding stoichiometry, conversion of all three pollutants is nearly complete. However, outside of that band, conversion efficiency falls off very rapidly. When there is more oxygen than required, then the system is said to be running lean, and the system is in oxidizing condition. In that case, the converter's two oxidizing reactions (oxidation of CO and hydrocarbons) are favoured, at the expense of the reducing reaction. When there is excessive fuel, then the engine is running rich. The reduction of NOx is favoured, at the expense of CO and HC oxidation.

[lordfury007]

I'm just stirring shit up, but most places of education won't accept Wikipedia as a reference or proof...

[JrZook]

royce wrote:

Llewellyn92 wrote:

royce wrote:

water is a by product of a catalytic convertor

sorry royce but that is incorrect, water is one of the products of the combustion of the fuel itself, dont you remember your ol chemistry lessons at school

Orly?

http://en.wikipedia.org/wiki/Catalytic_converter

Quote:

Two-way

A two-way catalytic converter has two simultaneous tasks:

1. Oxidation of carbon monoxide to carbon dioxide: 2CO + O2 ? 2CO2
2. Oxidation of unburnt hydrocarbons (unburnt and partially-burnt fuel) to carbon dioxide and water: CxH2x+2 + [(3x+1)/2] O2 ? xCO2 + (x+1)H2O (a combustion reaction)

[Jester]

well we aint most places, and in this case wiki is right, i could go reference my mechanics text books, but CBF theyre out in the car

[Llewellyn92]

good work boys you learn somthing new every day ... but i still reckon most of the water comes from the original combustion and only a small amount from the catalytic converter cheers