Take it to a mechanic, one that specializes in water damaged cars if you can find them. The list of problems from water damage far exceeds the ability of this site to even begin telling you of the problems you will most likely encounter.
No, it is not. BUT: Starting a car with the exhaust submerged carries other risks. By implication there are other things submerged that could be damaged by water, such as the alternator, HVAC, or transmission. Also, the engine may not start if the starter cannot overcome the water pressure.
There are many car engine damages that could occur to a vehicle from being submerged in water. Your car could short for example.
How do you know that it is your car?
check and make sure water is not getting in ur alternater cap
You need to warm the car up with hot water.
It wont start
Your car wont start. lol
Junk it! It will be a money pit if you try to save it.
use jumpers
What have you welded ?
ud be looking at a broking t belt plus water pump
how does it stall if it wont start?