My car sounds like it will die. Very shakey, when you start it rpm shoot up to 2 1/2 then straight down. On cold mornings a ton of white smoke from tail pipe. will over heat if I don’t add about 20 oz. of water to radiator daily. Sounds worrible when in park less as bad when idel in gear, not as loud if driving. We changed the water pump recently.Did I blow the head gasket.
If you have to add that much water daily, you have a serious leak. It sounds like a head gasket and one cylinder is obviously not firing, causing the shaky behavior.
There may be other problems, but you need to take this car to a good mechanic immediately before the engine is wrecked because of possible hydro lock.
Please keep us posted on what you find out.