Alright want to start by saying I am new so sorry if this post is in the wrong spot.

My boyfriend is in Cali right now for training, and is on a base where he can't use a cellphone otherwise I wouldn't even be here asking for suggestions.

Beginning of May, our 06' f350 superduty, started refusing to start. We were having to start it with ether until I could get it in for the glow plugs.

He left for Cali, and had me take the truck in for new glow plugs, and to have the fuel filters changed.

I started the truck a handful of times after, moving it around our driveway, parking the truck/trailer.

Drove the truck/trailer to a horse show an hour and a half away, unpacked and after an hour of unpacking the truck refused to start.

Finally got it started after a couple hours.

Took it back, had a mechanic try to diagnose it. No bad codes have come up whatsoever, it fired right up every time the mechanic started it. He let it run for a half hour, would try and restart it, and it would start no problem. Tried it cold, even short circuited the glow plugs to see if it would do it still nothing.

I took it back, drove 20 minutes away, half hour later try to restart it, and it wont start, and wouldnt not start with ether either. (I must just have that MAGIC touch )

Had it towed back, and STILL no bad codes. Fired right up after it cooled off.

Any ideas what could be going on?

Thanks in advance!