When is start my mazda 626 93 in the morning cold... It burns oil for about 20 seconds blue smoke pours out the back but then is stops... whats wrong and how can i prevent this??

 

This is common for cars with higher mileage and age. It comes from the valve guide seals in the cyl head. It will get more noticeable as the weather gets colder. These seals are rubber and get brittle with age. What happens is when the car sits overnight, oil seeps through these seals and sits on top of the pistons. When starting cold it burns that oil off until the next cycle.

 

So if i changed te seals it would fix the problem ?? how hard of a job would that be ?? Complete head removal ??

 

That should slow down the problem as there is wear on the engine that can only be addressed with a complete rebuild. The seals usually slow down the problem significantly. You do not have to remove the head for this repair. The main tools you need are an air compressor and a valve spring removal/installation tool along with hand tools. The compressor holds the valves shut while the springs are removed. The seals are underneath the valve springs.