We can only give as much advice as we have info to go on, as stated.
We don't know why the car overheated in the first place, as stated.
You have to keep in mind that these types of thread pop up regularly and the people posting them have wildly varying automotive experience. The more info you can provide, the more we can get a feel for just how much you know, what you've already tried and then we can direct you towards what the next steps should be.
Not being face to face is a real downfall of the internet. But we try our hardest to make it work well.
But as stated, really need more info to give any reasonable course of action here.
13 years, 124,000 members and still no sponsored racing.