Fan issue after YLOD

Hi, I recently bought a YLOD repair kit to fix my ps3. It worked, and now my system is up and running again. The only thing I'm concerned about, though, is that now the fan starts getting loud like it's over heating after being on for about 30 seconds. Is this something I should be concerned about? I managed to get the game that was still inside of it out, but I didn't want to risk damaging the motherboard irreparably, so I turned it right off. A few minutes later, I turned it back on to see if it would repeat. Any help would be great. Thanks!

Oh, not sure if it matters, but the system is backwards compatible.