2005 - timing belt question

Hoping someone who may have also had this happen or knows of it happening can confirm the accuracy of my mechanic's claim. He says it wasn't his fault.

I have a 2005 4-dr Limited V8 Auto 4WD with very low miles. I had the timing belt changed at 80,000 miles a few years ago. Now at under 110,000 today, mechanic says he has to change it again!

Took the vehicle in because the heater stopped working. Filled back up with fluid and it started working again, but then stopped. Turns out it's a slow leak caused by a gasket. As I understand it, this has to do with a fluid line that connects from the radiator to the engine. (?) As I understand it, this gasket took some work to get to and involved the timing belt. During the repair a tensioner rod was loosened (?) and now the timing belt slipped a tooth. Now I have to replace the timing belt again.

I've been going to my mechanic for years and would like to believe he isn't having me pay for his mistake. I'm happy to try to provide more details if needed in order to make sense so someone can answer my question. I clearly don't know much about the inner workings of my vehicle and definitely don't have $1500 laying around. Thank you!

 

Step 1: Get a new mechanic

Step 2: Sounds like it was his mistake if I'm understanding right and he needs to cough up the coin for the repair, not you.

 

Why does he need to install a "new" timing belt all he should have to do is reinstall the old one, it should still be in good condition to reinstall?

That being said if wherever the leak was if it allowed coolant to saturate the timing belt, I would replace it out of caution, the reason is coolant will deteriorate the timing belt and it could break and if it does the engine would be destroyed because the V8 engine is a "interference" engine...meaning if the valves are opened when the piston reaches the top of it's travel it will hit the valves and thus destroy the engine, with the timing belt broken some of the valve will remain opened as the engine continues to rotates until the damage occurs.

The leaking onto the timing belt actually happened to another T4R owner and about 6 month later his timing belt broke and he had to replace his engine.

 

I would ask for the diagnosis and repair that the mechanic did be put into writing. In detail. If they cannot put this into writing, then find another mechanic. If they can provide exact details, then post that here.

Also where are you located? Might be able to get some shop recommendations for someone near you.