I was involved in an accident. Unfortunately I was at fault, so I paid my deductable and expected my car to be fixed. My insurance company told me to take my vehicle to an auto body shop of my choice. After I picked up the vehicle from the body shop I started having problems with the vehicle overheating. The body shop looked at the vehicle several times after it was taken out and continued to have problems. One week later my vehicle did not start and was toed to the Dealer service department, come to find out it had a broken head and the engine had coolant in the head. My insurance company said they will not pay because they claim I drove the vehicle without coolant causing the vehicle to over heat and therefore causing the broken headt. They stated there is a clause in the insurance policy that states “if a vehicle engine is damaged a result of overheating the insurance will not be held liable” my question is how can they prove it didn’t have coolant, and how can I get them or someone to pay. The vehicle was perfectly fine before the accident. Thanks guys

The question is, how do you prove it did ? Since they are not writing the check, you will need to prove it did.
Start by getting several mechanics to write a statement that this damage was caused by something other than you driving it without proper coolant.
So what elst caused the head to crack.

Next what caused the over heating? I would assume you stopped the minute the car over heated and did not drive with it over heated,