So several months ago my timing belt broke, just bad luck. Had to get my engine swapped. I begin to have on/off cooling issues, my mechanic tells me he can't find the leaks (after several fixes btw) and to just top it up, it could just be air bubbles. So basically he can't fix it. I keep topping it up, realize I have a leak and decide to take it to a shop which specializes in Audi (Independent Tuning in Toronto).

TO make a long story short, my gasket got damaged due to the cooling issue and I have to dump $1800 again to fix this. Independent tells me today that several pipes were not installed properly leading to the cooling issues. What's my recourse here? Get my previous mechanic to come take a look and fix it on warranty? Can I even do anything at this point? They did a shoddy job on the engine swap, and now I'm in the hole for $1800. Thoughts?

 

Small claims court will handle this, it's not expensive and is effective.
But negotiate with them first - courts don't like to see you didn't try due diligence to negotiate a settlement first. If all else fails, sue them and advise them this will impact their credit rating and business rating, so it's in their best interest to help you out. GL.