trouble when continuous shooting

Lately when I want to shoot continuously, I can shoot off maybe 5 or 6 shots, but then I hear a noise, sounding like my mirror locking up, and it must be what has happened because I can't see through my lens, so I go to menu and select "lock mirror up for cleaning" , then I click on start and release the shutter, shut off the camera, and then I hear the mirror again and find I can once more look through my lens, this is very annoying as I will be continuous shooting to get some action shots such as a bird flying, and I am interrupted, does anyone know what I can do about this ? Thanks for any advice, this has never happened before, and I am worried that my camera needs to be repaired.,

Sounds like it may be the quality of your card, the camera is only able to write in continuous mode in 5-6 bursts because of the speed the data is being written to the card.

Thanks for your quick reply, my card is a sand disk extreme III and I have been using it for years, would the card cause my mirror to lock up ? that does not make sense to me, thanks , Frances

Try shooting with a very long exposure. Auto-ISO off, put it @ 200 and go outside in the dark. See if your mirror is still locking up.

Have you ever had your camera cleaned?

Thank you, ,this is what I was thinking that maybe my camera needs a check up and cleaning, I will have that done as soon as is possible.