Possible Blown 3SGE Engine

I recently filled up my oil as it was getting a bit low and then drove it up the street and after about 500m a massive cloud of smoke was pouring out from the back of the car. i let it cool down for about 15min and when i started it up again it was missing and idling rough and couldn't maintain a constant rpm. i think i may have over filled the oil but would that cause smoke out of the exhaust and the poor engine performance. also when i turned the car on the temp gauge wasn't working and this is the first time i have noticed that. any ideas as what the problem could be??

What colour is the smoke? I once accidentally over-filled the oil in my other car (significantly, because I had a faulty oil pressure switch that had me confused), and the car was billowing huge amounts of white smoke out the exhaust.

Its blowing out white smoke not a blue like colour, hopefully it is just an overfill of oil because when i was driving it it seemed fine until all of a sudden... 
 
Thanks for the quick reply guys

i drained the oil and ran it for a while and eventually the smoke has stopped and cleaned out the spark plugs and now all fine. as for the temp gauge when its back working fine now but when i noticed it wasnt working i was driving for about 3-4mins and it didnt move.  
 

Reddtarga

Great, so it looks like the motor is OK.

I have noticed on my car it takes noticeably longer for the temp gauge pointer to move in very cold weather.

longer than usual or longer than other cars??
SW20's and AW11's take ages to heat up compared to a normail car cause iron blocks take longer than alloy, and once the block heats up theres an aweful lot of cold water sitting in the cooling system... a LOT more than an average car cause of the distance to the radiator.  On mine i can see the needle drop back down when the thermostat opens... like its a two stage warming process....

On my car, (3SGE) on a cold winters morning it takes longer for the pointer to start moving after a cold start up, compared to a warm summers morning, and when fully warmed up the pointer sits in the middle of the dial and never moves.
 
Despite what many people think, MR2's have a well designed and efficient cooling system if properly maintained.

They are certainly different to front engined cars, but the amount of coolant in the rest of the system (radiator, pipes etc) won't have a bearing on engine warmup time, since both the  turbo and NA's have a coolant bypass system that only circulates coolant through the block until the correct temperature is reached, and then the thermostat opens to control the coolant temperature in the block by diverting coolant forward to the radiator.