sliding patio door header...

sharp

while doing renovation to kitchen I noticed the header over the sliding doors was sagging. It was only a 2X4. The doors operate fine.
I decided to fix the header. The doors are 6 ft long.
I wound up adding a header that was 2 2X8 on their side. Is this over kill? I'm worried now that it may be too much weight.
Also, when ripping out the old header some sort of plastic end cap came off that was attached to the 2X4. Is this something that needs to be replaced?

Also, there were three screws that went through the door into the header. I can only replace the first two that were accesible from the slider, the third was under the nonmoving door. Any way around not removing the door and fixing this third screw?

Anything else I may have missed? Don't want any leaks.
Will send pics if necessary, didn't have camera on me tonight.
Thanks for helping.

Just Bill

I have to assume that this is not a supporting wall. Even if it is not, you need somehting bigger than 2x4 to span 6'. I would have to see what you did to properly comment on the results, but for a header to properly work, it has to be supported on either end by studs, whcih are eventually supported by the foundation.

Done correctly, 2x4 cripples can work just fine, if the beam above is sufficient.

Ron6519

The weight of the header is irrelevant. It is just a wood structure that spans a distance. The size of the header is based on the load above as well as the span. You would need to supply more information to get a useful answer on the header size.
The fixed door becomes unfixed by removing a few screws. Spend the time to find these and secure the frame properly.
Ron