Do you have oil in the coolant, or vice versa? Likely, you've got a cracked head.
This is the byproduct of combustion. It's not problematic, and should not worried about, it's completely normal.
If the leakage is actually gear oil, this indicates worn seals, and or shafts'. Often times however, the leakage is not gear oil, but rather unburned fuel that has run down the exhaust housing, and leaked out of the gearcase. A pressure / vaccume check should confirm, or rule out, seal failure / worn shafts in gearcase.
theres a very good chance that the engine has a blown head gasket. what is happening is the water cooling the engine is escaping past the head gasket & into the engine, mixing with the oil making it milky coloured. the water is also escaping into the cylinders, making the steam come from your exhaust, you may also have trouble when turning the engine over, with water building up in the cylinders when cooling down.
Valve cover gasket
Could be blowin by piston rings and burning up and out the exhaust.. if that's the case... blackish smoke will come out exhaust when revved
White, water vapor. Gray/black unburned gasoline. Blueish, burning oil.
This is the byproduct of combustion. It's not problematic, and should not worried about, it's completely normal.
normally blue is worn rings,and black is unburned fuel.
It's carbon and unburned oil that you put in the gas mix. Using a gas mix with less oil will eliminate some of the unburned oil that comes out the exhaust but you need to be careful you do not run the engine with not enough oil in the gas as that is the oil that the engine needs for its lubrication.
If you're sure it's "smoke", then it's probably burning oil. But most likely it's water vapor. When an engine is first started and the air is cold, the water vapor in the exhaust will create visible steam. Automotible exhaust primarily consists of carbon dioxide and water vapor. If the engine and exhaust system are cold, the exhaust will be cooler when it comes out and it can create a cloud of water vapor. However, if it's not water vapor, as I mentioned above, it could be oil smoke. If that's the case you need an engine rebuild since you probably have bad rings. For the record, I haven't seen many newer GMC's that burn oil.
There is nothing to worry about with water in the exhaust. However water in your oil could suggest leaky gaskets. Depends where in the oil system or engine it is.
engine burning oil( white or blueish exhaust smoke ), water in oil, oil in water, water in exhaust.
Usually a blown gasket, usually the head gasket. It creates a seal between the oil and the combustion chamber. When broken oil can leak in and you will have smokey exhaust and a dramatic drop in oil level, or exhaust gas (which includes H2O vapor) can mix with the oil. This is a very serious problem and can lead to severe engine damage.
If you are asking about contrails it is dependent on the temperatures aloft. At colder temperatures the water vapor in the exhaust condenses and causes the contrails you see. The blue angels and other aerobatic-performance aircraft inject a special oil "smoke oil" into their exhaust in order to leave the smoke trail you see at airshows. But the "smoke trail" you see behind civilian and commercial aircraft isn't smoke at all, it is water vapor formed as described above.
It means that it has absolutely nothing to do with the oil and filter change. Backfiring is caused by unburned fuel/incomplete combustion/carbon buildup/incorrect ignition timing. The unburned fuel vapors pass into the hot exhaust and ignite just before the 1200 degree catalytic converter causing the backfire. However, ensure that you always check the oil level after having your oil changed by a third party.
It's the same for all internal combustion engines. When gasoline burns inside the combustion chamber, it produces carbon dioxide and water vapor. The water vapor is usually hot enough that you don't see it, but when the weather is cold, and while the exhaust is still cold, some of the water vapor will condense together with other water vapor molecules, producing a visible mist that looks like white smoke out the tailpipe. It's normal. On the other hand, once the engine is warmed up, if the white smoke continues and if you notice that the engine is using a lot of oil, it may be that the rings and/or valve stem seals are leaking, allowing oil to enter the combustion chamber. When that happens you'll get some oil burning, which may look whitish-blue.
there is no water mixed with the oil but have antifreeze coming out of the exhaust