Hmmm something strange happening here…
You state:
1 14-16 months earlier, bottomed out on a dirt hill and snapped the air conditioner line.
2 Took it immediately to Ford Dealership.
3 They were busy for the next 3 days out and recommended I go to the mechanic literally 200 yards down the street.
4 The second mechanic held the car a few days to order the part, the AC line on the bottom of the car that snapped, and replaced it, and the car was good to go.
Next
5 Since then I’ve had the car taken into the Ford Dealership itself 3 separate times for the normal checkup. They do a multi-point inspection each time and absolutely zero of the times did they give me any indication anything was wrong.
First question to ask is what does their ” multi-point inspection ” consist of?
It may / can vary from dealership to dealership
Here is one found on line: https://www.sherwoodford.ca/blog/whats-included-with-ford-multi-point-vehicle-inspection/
6 Roughly 1 1/2 years later, engine overheats P1299
Did you not see the temperature gauge or indicator light on the dash when this happened, it normally sets long before the engine seriously overheats.
7 Next day I get the car to Ford. They keep it for several days, and then slap me with a $5000 repair bill. They said there wasn’t any coolant in it, and that the exhaust port was cracked, coolant got into the motor, and one of the cylinders was cracked and needed to be replaced. I told him about the accident and the Ford guy told me the main line mechanic says the radiator was out of place and the air ducts were messed up and the mechanic believes all of this damage stems from my bottoming out 14-16 months earlier. $5000 repair bill.
I have a professional mechanic of 20 years for a friend and I called him, he said the mechanics should have caught those things during the multiple inspections, but technically they’re only supposed to address what I go in for.
This is quite true.
Now lets see what is possible.
Knowing you bottomed out the vehicle and had specific repairs done at another shop (which I assume were good) did you tell them you bottomed out and also want it checked for any other possible damage?
Did you ever take it back in to the dealership or another mechanic and specifically tell them you bottomed out and what the car checked for any possible damage?
Most dealerships and mechanics do what they are specifically instructed to do because of costs involved.
Most people are not willing to pay for “extras” that weren’t specifically asked for.
As to the damaged:
Lets look at that, you state this happened 14-16 months after the fact.
IMHO, the closer to truth on this is you may have caused some latent ( not so extreme) damage when you bottomed out and over the course of time fatigue caused the failure, or perhaps some minor damage occurred when you bottomed out and perhaps rough roads (pothole) or your driving habits stressed the issue to the point of failure.
Bottom line here is, after you bottomed out it was up to you to specifically ask who ever you brought the vehicle to that you had a incident, what exactly happened and want the vehicle inspected for any possible damage.
Also to get it in writing so you have some type of proof.
I can not tell you that the dealership or mechanic is fully at fault here, they will only do what you ask them too.
If you weren’t specific enough in your directions to them on this, I’m afraid a bulk of this is on you.