Anti-freeze leak in the front middle nissan 2000 xterra once was told to watch it may be headgaskets

Best bet is a dealer as the keys must be associated with the car VIN.

If you can smell,then you have a leak,if the heater core has a pin hole,then the box that houses it will hold the antifreeze to wear you won't see any,have to take the box apart and see,check your hoses going thru the firewall to see if there leaking.

There is a small bypass hose that goes from the thermostat housing into the top of the water pump. You have to disassemble quite a few things to even get a look at it. It is a common problem and needs to be fixed as soon as possible. It is located directly above your timing belt and the antifreeze will cause your belt to degrade and fail, then you will be replacing bent valves.

Bad idler sensor possibly or abs sensor

maybe a haynes repair manual would help.check your auto parts store or on ebay

YOU NEED TO START BY PRESSURE TESTING THE COOLING SYSTEM. YOU CAN GET A TOOL LOAN AT ADVANCED AUTO PARTS.LOWER INTAKE LEAK WILL SHOW UP THIS WAY YOU CAN ELIMANATE IT ,THEN YOUR PROBABLY HAVE ACRACKED CYLINDER HEAD OR ABLOWN HEADGASKET

yes it has freeze plugs,water pump may be leaking,fuel pump has nothing to do with coolant leaking

Better have it checked for a possible headgasket leak. This can destroy an engine!!! (They can leak coolant into the engine oil)

As for the AC problem it has a leak somewhere if it worked good for a day.Have it pressure tested for a leak.

I have seen a couple of these now with headgasket leaks to the outside of the block just as you describe. I solved them both with a stop-leak additive, not something I would normally use, but I really didn't want to pull the heads because the exhaust studs always break on these engines. I would find out for sure where the leak is before proceeding though. If it's a hose or frost plug, you'll have to repair it properly.