Fans at full speed, plus laptop being very slow

So a few days ago I accidentally spilled coke on the trackpad area of my MBA. I dried it off with a towel and though it wouldn't be such a big deal, as it seemed to be just external.

I turned it on again and to my surprise, the trackpad was behaving funnily, so I turned it off, poured some rice over it and put it near a heating system the whole night.

The next day, the trackpad was working perfectly, but now the fans were going at full speed (6500), despite it being any hot or being forced to do any tasks. It did feel a bit slow but that I did not completely realize until later...

I downloaded an app to slow the fans down and thought I'd be alright, but as I opened a video game, I notice how now from 50 FPS, it went right down to 15, sometimes even down to 02 FPS when there was some action going on... so pretty much impossible to play.

During the weekend, I tried to work on some photos (I work with photography and edit them on my mac) and as I used lightroom, I found it also extremely and annoyingly slow. Almost to the limit of not being able to edit anything without having to wait a few seconds for any action to take place.

Further research took me to read that there might be a problem with some temperature sensor located nearby the trackpad. It is not communicating well with the laptop, and makes it think that it is very hot, (hence the fans going at full speed) and also some processing $@$* is going on in between and it exhaust my macbook, so that makes it so slow. I called apple support as I still have the warranty active, but they say liquid damage won't be covered. They want to charge me over 60 euros for just taking a look at it, and if I decide to get it fixed, It could end up in a couple hundred euros I don't even have.

I want to know if there is a way of getting this fixed, what tools I would need, and what should I be trying to look at. Apple support told me there could be some sugar residues and that has to be cleaned off, maybe nothing really needs to be repaired or replaced, and if that is the case, I would really like to get hands on it as soon as possible, as this laptop is my work and without it I can't do anything. Those 60 euros are not an amount of money I currently possess, and I really need to get this done soon!

Thanks in advance, for your time and your answers!