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White smoke out exhaust

Yoo i just bought my infiniti m56 s like a month ago… so bout 2 weeks ago it started misfiring so i took it to my mechanic by the alameda in san jose, he checked spark plugs, coils, injectors and even changed the fuel pump. It stopped missfiring and i could drive it but every 25 sec or so on idol it would sputter. It was starting to get out of hand when last night i drove down the street and i just see hella white smoke coming out, the sputter just switched and turned into a continued rough idol. Checked my oil and now there is none like bone dry, white smoke still coming out exhaust. But it was driving good and there was only white smoke on idol not when i was pressing the gas. the car wasnt overheating. The only code that came up after the missfire was fixed was catalytic converter error code. Idk what it is do u Guys have any idea???

The white smoke means you are burning engine coolant inside the engine. The vehicle is likely cutting off due to high engine temperatures.A blown head gasket is the usual cause.It is very unlikely that your engine was not overheating…maybe you didn’t notice it when it did

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I think you just found out why the previous owner sold the car!

I think that white smoke is engine oil seeing as how the oil is “bone dry” as you say. The engine in this thing sounds like it is burning a ton of oil. It could be a number of things… the worst of which is the engine is junk.

It needs a good mechanic to diagnose whether this is a crankcase vent problem, stuck or broken piston rings. Not sure if your mechanic is a good mechanic or just a parts changer.

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So, you added some oil? How much? Hope it was not 5qts

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I also suspect that you are burning engine oil at such a rate that you are fouling the plugs and killing the converter. Oil smoke is blue gray but I imagine it looks white at night.

Depending on the year and condition of the car, this might not be economically fixable. I think you need advice from a better mechanic than the last one you went to.

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Yep white smoke is usually steam from burning water/coolant, unless it is a diesel then it’s injector pump time.