Over heating, smoking, slows down to 20-30 seems like it starts bogging down maybe?

so I traded my 05 for a 84 c4 always wanted one for sentimental reasons my family had one, so I was told the motor was rebuilt 20,000 miles ago, and I really want to keep the car honestly really hate that my first experience with a corvette has been sour because I was so excited to Get my first one and waited till I thought I found the perfect one now here we are smh, but anyway the motor sounds Good most of the times sometimes at idle there’s a slight backfire from the exhaust, doesn’t cut off though, but when it Gets up to running temp I Guess as I’m driving could be as short as around the block it Gets hot smokes from passenger side behind motor between motor and passenger seat and won’t Go over 20-30 mph this is my final cry for help lol if I can’t Get it figured out I Guess I’ll be Giving the car to a scrap yard and starting over… any help would be Greatly appreciated sorry for the bother

 

Welcome to the forms. It hurts me that you think of your car as scrap.. Sounds as if you have several things going on. Is it possible you have an oil leak over by the starter somewhere? Could be leaking from the rear of the engine and running down by the starter, maybe a small puddle of oil on the right side of the engine when you park the car? As if it always leaks but smokes when the engine warms up and the exhaust pipe gets hot? When it over heats what is the engine temp gauge reading? If it gets up to the red area on the gauge? If it's close to or in the red the cars computer goes into Limp mode just so you can get off the road. What's the condition of the coolant? is it full? Is it nasty and needs flushing? Does it have a good radiator cap and holding pressure? What is the condition of the thermostat? Does the top radiator hose get warm up when it reaches 190 degrees and not before? I would check the water pump, take the belt off and spin the pulley and see if it spins smoothly and no water leaks. Spin all the pulleys when the belt is off. If the cooling system does not pressurise the bottom radiator will collapse on itself and overheat the engine at moderate and high RPM. They don't use wire coils in bottom radiator hoses like they did in the 70s and before. I think you have a few minor problems causing an issues. Fix the oil leak. Check the cooling system for a bad thermostat, radiator cap, maybe a bad water pump or leaks. For missfiring maybe a tune up with wires.

 

Well said Thomas, about the only thing I can add at this point is to also check the radiator find and make sure it is not clogged up. This could be an easy problem to sort out but you have to cover the basics. Let us know as you proceed and we'll try to help.

 

There is a possibility the radiator fins could have a fair amount of debris in them over the years, hard to tell sometimes with the condenser in front of it which most cars had a/c. Blown head gasket or water pump failure is unlikely also, but possible. I wonder how warm the engine is getting, could it be normal high temperature? (190-195) could be the ECM temperature water sensor is failing and telling the ECM the engine is hot when it's not, putting itself in limp mode. Without knowing the temp of the engine just leaves me guessing.