Smoke and Pop

[eclipse2quick21]

ok i have two questions

1. my exhaust spits out white smoke, ive been told its something with the valves. anyone else think they know?

2. my new cat-back exhaust pops and crackles. i hear alot of cars doing this after new exhaust. why is this?

thanks to everyone that is going to help me out with this. thanks again.

[MagicRat]

Some white smoke is normal. Water vapour is a by product of normal combustion, and is noticeble in the first few minutes of running the engine. This is when the exhaust is cold and the water vapour falls out of suspension and condenses. You are making clouds, in other words. However, this clears up after a few minutes unless the air temp is well below freezing.
If you have LOTS of white smoke pouring out the tail pipe in large quantites, then likely you have blown head gasket and you are burning coolant. This exhaust would have a sweet smell, but don't breathe it in much, as its hazardous.
As for the Rice Krispy exhaust, does this happen when you are slowing down in gear with your foot off the gas? If yes, this is just unburned fuel getting into the exhaust then combusting. On some cars, its there all the time, but a stock exhaust system muffles the sound, so you only notice it with a louder exhaust. Generally speaking, it shouldn't happen with a fuel injected car, since the electronics controls the fuel mixture well enough so excess fuel does not go into the engine. If this is the case, it might indicate you have a fuel injector problem.
Sometimes a carbureted engine will do this, because they are less precise in delivering fuel.
If your car has a carb, it might need a carb adjustment or tune up. Otherwise, I wouldn't worry about it much.

[eclipse2quick21]

Originally Posted by MagicRat

Some white smoke is normal. Water vapour is a by product of normal combustion, and is noticeble in the first few minutes of running the engine. This is when the exhaust is cold and the water vapour falls out of suspension and condenses. You are making clouds, in other words. However, this clears up after a few minutes unless the air temp is well below freezing.
If you have LOTS of white smoke pouring out the tail pipe in large quantites, then likely you have blown head gasket and you are burning coolant. This exhaust would have a sweet smell, but don't breathe it in much, as its hazardous.
As for the Rice Krispy exhaust, does this happen when you are slowing down in gear with your foot off the gas? If yes, this is just unburned fuel getting into the exhaust then combusting. On some cars, its there all the time, but a stock exhaust system muffles the sound, so you only notice it with a louder exhaust. Generally speaking, it shouldn't happen with a fuel injected car, since the electronics controls the fuel mixture well enough so excess fuel does not go into the engine. If this is the case, it might indicate you have a fuel injector problem.
Sometimes a carbureted engine will do this, because they are less precise in delivering fuel.
If your car has a carb, it might need a carb adjustment or tune up. Otherwise, I wouldn't worry about it much.

you wouldnt believe how much you helped me lol. thanks. but what if theres also a mixture of black smoke coming out to? yes, the popping is only when i let off the gas and slow down. so i shouldnt worry about it? thanks again.