Loud fan after changing the upper case

Hi guys,

Today I replaced my upper case on my macbook air 13” Mid 2011, all looks that went well, I didn’t loose any screw and I followed ifixit steps. But when I turn on my Mac, the fan is very loud. I did check the error with apple diagnostic hardware test and it came out with the following error: 4mot/4/40000002: Exhaust - 0.

So right now I am thinking to buy another fan, one of the things that I did wrong when I remove the fan from the case is that I didn’t pry up the hinge retaining the flap and I just pulled the flap, so that could have damaged the flap.

What do think? Do I order a new fan or it could be another thing?

I did try reseting the SMC but nothing.

Many thanks

Ramon