Rx8 engine (under the hood) is smoking
 

Hi today tryed to start my mazda rx8 2003 1.3L, 74000 km it wouldn't start at first, then it started but check engine light started flashing and alot of power had been lost and it was idling at about 600to 700 rpms, the engine it self started to smoke (white colour), i drove it to the mechanic and he said he will look at it and told me to leave it there for a week, he assumed that i had blown an apex seal but he is not sure yet as he hasn't done any tests. There was no smoke from the exhaust only the smoke was under the hood. Do u think it could be anything else other then an apex seal. The oil presure was normal, the coolant level normal also.
I warm up the car before starting it btw and live in australia

White smoke is usually coolant.

BC.

you blew at least the trailing coils.

A broken Apex is not going to make the engine smoke under the hood. A coolant leak or an oil leak are the likely culprit.

An apex failure is catastrophic failure. You would notice that by the way the engine runs and starts. Or doesn't start.

The engine starts after about 10 to 15 seconds and idles at 600-700 rpms, the car runs because i drove it to the mechanic but just barely. there's no smoke from the exhaust also.
The smoke smells like plastic or electric burn, and it only smokes when u drive it, it won't smoke at idle
btw i had added engine oil to the car 1 day before it happened and spilled a bit around the engine oil cap

Bingo!
Overfilled or spillage is most likely the source of most of your issues.
Check your intake track for oil and clean the MAF.

Thx guys for the help, the mechanic said crank angle sensor has to be replaced and coils and leads also have to be replaced.

guys the coils and sensor will arrive here in couple of weeks but i just noticed today that the car had black debri coming out of the exaust, is that bad or no

Define "debris"
If you mean there is some soot and it's getting on your tailpipe, then that's fine.
If you mean you are blowing chunks on any real size, then that could be pretty bad and could be the CAT disintegrating.
I don't remember if you had taken the CAT loose and peered inside with a flashlight to see if the honeycomb was still intact or not.

Hi there i got a mazda rx8 2004 tiptronic .I drove it lfor like 3 hours .checked all the engine oil,transmission oil and coolant everything were sweet.and last sunday i was going to drive it ..and i started it and warmed it up it says on the odometer or dashboard like a faucet i think its the radiator thing?as i could see it i opened the bonnet and thre was smoke coming underneath of the engine coolant top up? please help me on this situation please ?? thank u very much ..

^ Coolant Leakage..?