What might have caused new car with 29000 miles have white smoke from exhaust?

This is what I found. Welcome to Fluther.

I was going to say that the engine has elected a new Pope, but since this is general, I can not do that, so I can only refer back to @bkcunningham.

White smoke is usually water vapor. Have someone check the exhaust system, especially the catalytic converter and if that’s okay, look at the engine. Water is getting in to the combustion chambers. And yes, welcome to fluther.

Take it to someone to look at.

White smoke is indicative of a blown (or leaky) head gasket which is now allowing coolant/water into your engine and oil into the coolant/water. This is extremely bad for your car on multiple levels. You can check for this by pulling your dipstick out and checking for any milkiness in your oil (it should just be pure oil).

Driving like this will destroy your engine very quickly. If it is just leaky it will only get worse, and probably at an exponential rate.

It’s also that weird season called winter when everyone has “white smoke” coming from their exhaust due to combustion byproducts being hot and the air around your car being cold….

I’d take is to a garage and have someone make sure there is an issue before you go ripping stuff apart.

But checking your radiator fluid wouldn’t hurt. When one of my radiator hoses rotten through (on my 91 MR2) and my engine overheated it was plooming white smoke from everywhere in the engine bay.

@Deshi_basara There’s a definite difference between head gasket white smoke and cold weather/heat smoke. If you can’t tell the difference by looking at it, it’s probably not the head gasket.

I am assuming you are not talking about driving in cold weather when you should expect to see some white smoke. That is normal.

However, if it is hot and you have excessive white smoke, a big change from before, it is most likely a cracked head or broken head gasket. Coolant is getting into the cylinder. Look at the spark plugs. One plug will look different from the others indicating which cylinder has the leak. Even if it is one cylinder you will need to change the whole gasket.
If you have a head gasket leak check your oil and coolant levels frequently. If you continue to drive it for a while you will notice your oil will begin to change color and the oil level might slowly begin to increase while your coolant level will decrease.

Welcome.
Here is my thinking:

Sound of hissing possibly is a vacuum leak.
Intake manifold is under a vacuum.
Part of accident caused a leak in intake manifold which has a connection to the cooling system.
Fluid is now in engine causing white soke.