# Head gasket or what?



## versace (Apr 16, 2006)

I have 93 Altima, 145K. White smoke is coming out of my exhaust, but it smells normal. I see the smoke when I give it gas, especially like from a stop sign. I'm not losing any anti-freeze and it looks normal. I'm not losing any oil and the oil looks fine. I might be burning more gas than usual, but I haven't checked my mileage. When I took out the spark plugs to change them, they smelled like gas. I did a manual diagnostic and it said Code 33, which means something is wrong with the oxygen sensor. Can this sensor cause the white smoke or is it the head gasket? The car runs fine, it starts right up and drives smooth. What can be the problem?


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## Altima SSS (Oct 10, 2007)

If you are seeing "white smoke" then it's probably water vapors from normal combustion. Does the "white smoke" disappear after the car has warmed up? All vehicles will show "white smoke" when started up and during the warm-up period on a cold day.

It might be this that you are seeing ... especially if the coolant level is not going down.


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## versace (Apr 16, 2006)

Thank you Altima SSS. The white smoke doesn't go away after the car is warmed up. It also happens in warm weather. I can see it any time, even though it is not that much, but when I give the car gas, there is more white smoke.

The gas mileage is also bad now--I average 18 or 19 between city and highway. When I did a self-diagnostic on my car, the computer flashes 3 long and 3 short flashes, which means O2 sensor, but also 5 long and 5 short flashes, which means normal operation.

I am not losing any anti-freeze or burning oil, and the car runs fine. The O2 sensor is probably causing the bad gas mileage but could it be causing the white smoke too? If it was my head gasket, I would be losing anti-freeze or burning oil, but I'm not, and if I was leaking gas it would cause blue smoke not white, right? So what else could it be?


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## francisco006 (Dec 15, 2007)

the white smoke is most likely from a bad O2 sensor. It will make ur car run either lean or rich and it seems that in ur case is rich so when u do replace the O2 make sure u change ur oil because if it was flooding it, then some amounts could have gone past the rings into the crankcase and diluted the oil. that could take the protective coating on the main and rod bearings.... (theres a tool for taking n installing O2 sensors so that u dont damage the wire)


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## 95_altima_ka24de (Jan 2, 2008)

francisco006 said:


> the white smoke is most likely from a bad O2 sensor. It will make ur car run either lean or rich and it seems that in ur case is rich so when u do replace the O2 make sure u change ur oil because if it was flooding it, then some amounts could have gone past the rings into the crankcase and diluted the oil. that could take the protective coating on the main and rod bearings.... (theres a tool for taking n installing O2 sensors so that u dont damage the wire)



or if you just take of the heat sheild a 7/8 wrench is fine for the O2 sensor ......i just put in a header and exhast so you really dont need a tool just be carefull of the radiator while use ing th wrench ......^ but that is good info tooo good to know


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## birdsflyingover (Dec 19, 2007)

yeah, just smell your oil and check the level. if it smells like fuel and is above where it should be then you are getting excessive fuel dumped into the engine. yes, the 02 sensor could be at fault. seems like a simple problem, however, if the car is running so rich you are getting white smoke, it seems like it would be running horribly. 

if you are replacing the 02 sensor, who cares about the wire. cut it off, heat that thing up for a while with map gas and crack it loose. hint, you should not have to double wrench it or use a cheater bar. if you do then you are probably stripping it out rather then un screwing it.


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## 95_altima_ka24de (Jan 2, 2008)

question i just added a header and exhaust is it normal if there is a smell that i haven't smelled from it before i think its from the header, like from the heat burning the chrome off the metal....is this correct?


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