My fiancee's Jag is losing coolant daily (maybe 2 cups)

so far checked:
Underhood......No drips or residue that i can see
Exhaust:.....No smoke across the powerband

what are all the possible problems it could be so i can check one by one?

 

Radiator cap might problem as well .However I don't think a bad cap causes that amount ofloss in a day .Did you check all the hoses ? A slight crack to the raditor reservoir can cause the problem too .
Welcome

PS- It sounds a better idea to do a cylinder pressure test

 

I visually checked some of the hoses....but i'm not familiar with jaguar.

Who could do a cylinder pressure test?
I'll check the radiator cap when i get home from work.
i'll recheck some hoses as well

 

I think normally the coolant loss are the clip on the radiator hose at the bottom of the engine causing the hose to come off but this would be more obvious.
Check thecoolant (under water reservoir cap) to see if it is milky (caused by oil coolant leaking into thecoolant inside the engine) which would maybe suggest head gasket failure...but then that might also cause pinking etc?

 

Found the leak
It's something to do with the climate control. only happens when you switch it on
please follow link

http://www.youtube.com/watch?v=nY0iAT-occ4

Looks like something got crumpled down there... Any idea what it is?

 

That looks like normal A/C condensation to me. Check your oil and see if it is lighter in color or milky. Sounds like you might be on the way to loosing a head gasket. There are two ways to blow a head gasket.....

The first way is most common. Water in the oil, white smoke out of the exhaust, etc.... This happens when you blow out between the cylinders. The other way doesn't have too many obvious symptoms except for strange coolant loss in the beginning stages. This happens when you blow out a water jacket which is usually near an oil jacket. If it doesn't make it into the cylinder, the engine won't smoke and the pressure will be normal, however you're pumping water into the oil anyway without major symptoms.

 

Headgasket came in my mind as well.Hopefully ,it's not the problem .As far as I know, unless you smell some burn coolant out of the exhausts ,white smoke and overheating the headgaskets to the car should be fine .

 

It was definately from the hole. you see it dripping slowly in the vid, but when the heater/AC is on, it's a stream.

 

We didn't say it wasn't from the hole. I said it looks like normal A/C condensation. You need to take that one in for service.

 

If that fluid is clear, its just condensation.

Check the reservoir and hoses for leaks. Waterpump (left of battery if you are facing in front of the car).
Upper radiator hose leaks near the thermostat housing.