Here are some possibilities.
Radiator could have deposit build ups in it. (unable to dissipate heat like it used to)
Cooling fans not working properly.
Control system for the fans not working properly..
I have even seen a plastic bag road debris stuck on the radiator before!
Without hands on, it is hard to pin anything down.
Just going on what "your guy" suggested (he had hands on), I am going to send you information about the relays.
You did not provide much information, so I guessed you have a 1.9 liter when I looked this up.
Below are two screenshots (same diagram) The first belongs on top of the second. This is the cooling fan system for a 1.9 liter. Click on them.
You will see three relays on it. You will also see fuses.
Cool thing is, Their locations are listed!
We are assuming the fans will run.
I would check the fuses first.
I also looked for the relays at a popular auto store.
You will have to compare them, maybe even look for each one at other online stores
I believe this is the one on the far left, It might be for the high speed. They only show two.
I think this is the one on the right (low speed).
These should be easy to find (diagram) and easy to change.
Before you go spending blindly, see if either one works, narrow down your guessing!
I hope it is this easy, and not other things I listed.
Images (Click to enlarge)
Sunday, June 18th, 2017 AT 6:06 PM