Car will not start, no error code shown?

Hello,

My English is not very good, and I hope I'll be as clear as possible.
I bought a car in February from a secondhand car shop, and it worked just fine until one week ago. The car is trying to start it rattles but it doesn’t start. It's with a power button. I've tried putting the key inside then press power start isn’t working. So, I went to a mechanic and they showed no error code, I thought if maybe it’s the ECU as I read some internet stories but the car electrician which came to see the car didn’t see any error code also. The mechanic there don’t know what to do to my car as he checked it and wants this week to dissemble and assemble back some parts of it to see it something is wrong. But overall as they don’t saw error codes, they don’t know what to do.

I have to note that I don’t know if this is something important or not, but the car consumes a lot of coolant (car is ecoboost) I had to add coolant quite frequently. I went again with this problem at a mechanic around March and they also didn’t saw where and if it leaks.

Now I wonder if somehow this influenced my car not to start anymore or if it’s a normal this for an ecoboost.

In any way I'm sorry if I didn’t explained very good I tried my best and will provide more info if necessary. I just want my car to work, haha.


Updated the miles I thought we’re in KM.
So, it’s 150,000 km approximately.
—Maddie