Timing chain set replacement

I had to have the timing chain replaced on my 03 cadillac cts, this was done at the dealership. Since I have had the car back it seems to be one think after another, I'm just wondering if you might educate me as to whether or not these problems can be from them doing something wrong or breaking something while replacing the timing chain. Two days after bringing the car home, it started overheating, I took it back and the claimed it was a hose that they think they have repaired, but if it doesn't work then I will have to have a new radiator. One week after that, the air conditioner stops blowing cold air and there's a green oil stain under my car. I have not contacted them about the air conditoner yet.

Hi, At what mileage do I need to change the timing chain?

Can I get just a timing chain diagram for my car listed above it has 3.6l dohc engine?

Camshafts are out of sync.

Found out what was wrong with the Cadillac. It was out of motor oil causing timing chain guide to clatter put in four quarts of oil and problem solved.

In response to the question about the timing marks not lining up after turning the engine over manually, I had the same issue. I think it is due to the different number of teeth on the sprockets so that everything does't line up in the same spot every revolution. I followed the instructions for setting timing and made sure all the marks lined up, set the tensioners, and after turning engine manually none of the chain marks lined up anywhere. It made me kind of nervous but after reassembly the vehicle started right up and ran fine.