I changed my spark plugs on my 1990 300zx and now white smoke comes out the back and if i rev the car it has a really hard time staying on but it does stay on when i dont rev it. Nothing got in the spark plug holes while i was changing them. But i did a diagnostic test which said i had bad o2 sensor and the detonation sensor has a problem. Could those two thing be the reason why there is so much white smoke even tho before i change the spark plugs there wasnt smoke like that coming out?? Any help would be great im scared cuz i love that car and it was a pretty new engin
White smoke after changing spark plugs?
All of the cylinders aren't running. The O2 sensor is probably just reading out of range becaue of the junk getting pumped out of the bad cylinders. Fix whatever you did wrong with the plugs and the other readings will go away.
The things that go wrong while changing plugs are...bending the electrode when you put the plug in...getting the wires back on the wrong place...not getting a wire plugged on all the way...loose plugs...stripped plugs...missing plug sealing rings. Don't forget to check the wires at the distributor and coil too. They can work loose when you pull them off the plug.
And check the vacuum lines to be sure you didn't knock one loose.
White smoke after changing spark plugs?
Is there a chance you mixed up a couple of spark plug wires? Those sensors need to be fixed now.
White smoke is usually coolant in the combustion chambers.
Blue is oil burning smoke.
Black is poor fuel / air mixture.
If it truly is white smoke check for sludgy light brown engine oil or air bubbles blowing in the radiator with the engine running. (Open the rad cap with the engine COLD, right?) if you have either of those, you have a head gasket or cracked head problem, maybe.
If the plugs are correctly wired, I really don't see any possible relationship between the white smoke and the new plugs.
Could you have possibly disconnected or loosened up something while accessing the plugs?
sounds like a head gasket is leaking.
