A few nights ago I turned my car on to warm up because temps have been close to zero.
Out carelessness I forgot to turn the car off and left it running for like 12 hours.
So I turned it off and didn't try turning it back on til yesterday. I've attached a small video of what's going on.

Link to video
click ->
Any ideas on where to begin to diagnose?

I checked the battery and voltage is above 12.6V
No Check engine light.
Not out of gas.
No fluids under the car.

____

 

Looks like a clogged primary catalytic converter. You may have to change the exhaust manifold as the primary cat is attached to it. The dealership will charge the most. Fortunately, you have aftermarket options if you don't like the dealership price.

 

Where is all that smoke coming from? The hissing makes me think you've got a cooling system problem. Exhaust totally clogged?

 

I just have to ask, how did you forget about it running for 12 hours?

 

appreciate your response. Is there a way to test and verify that? possibly loosening up the bolts at the manifold? thanks

 

On second thought, a cooked cat would probably throw a CEL.

Chunjee mentioned your coolant system. Have you checked the coolant level in your overflow tank?

 

it looks to coming from neat the cat area. ill double check tomorrow. I dont know for sure if its clogged. I havent taken it to a shop yet to get a diagnoses. Im just trying to get an idea of what to look for first.

 

LOL i went out to warm it out late at night like 10sih. I usually do it in the morning. We had snow in the morning so i didnt go out. I went back inside and started watching a movie, couple of drinks and fell asleep.

 

I check the overflow tank and its normal. The morning i turned it off the temp was normal and no check engine lights. I cant keep the car on long enough to see if it will throw any codes now. The smoke smells more like heavy exhaust fumes and not like it was burning coolant smell. Ill double check that and anything you guys think i should look for.

 

Normal coolant level is great news. Probably nothing wrong with the head gasket.

Heavy exhaust fumes coming from the engine bay is another possible indicator the cat internals are clogged. I'm still guessing so you may need a second opinion. Good luck with the fix.

 

One easy way to tell if the cat is clogged is to measure the heat on each side. If one side is hot and the other is much colder, its restricting exhaust. Ideally this is done with a thermometer gun but I don't have one so a gloved hand is what I use.



That seems likely but check out the coolant too because a car overheating itself for 12 hours would be really bad obviously.

 

Cool vid, Chungee. Thanks for the info.