Loud noise when air is on had belt tension replace still making noise now im told its the engine mount

which engine option, you do know belts are not same on all engines right? fact.
2.7L V6 or bigger? IDN.

same on all cars. (answering in generic form do to above)
loosen the tension-er.
take off old
put back new
and if not a spring tension-er,set proper tension
the fSM cover all this.
why not read the manual, RTM?

here is one example (get the book, RTM or see alldata.com)

2008 xl7 engine


Removal Procedure

Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement .

Install the engine support fixture. Refer to Engine Support Fixture .

Remove the engine mount strut bracket. Refer to Engine Mount Strut Bracket Replacement - Right Side .

Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .

Remove the engine splash shield. Refer to Engine Splash Shield Replacement - Right Side .

Remove the right side engine mount bracket. Refer to Engine Mount Bracket Replacement - Right Side .

Lower the vehicle


Rotate the drive belt tensioner clockwise to release the drive belt tension.

Slide the drive belt off of the belt idler pulley (1).

Slowly release the drive belt tensioner.

Remove the drive belt from the accessory drive pulleys.

end remove
beg, install



Install the drive belt to the crankshaft pulley, the tensioner and the generator.

Rotate the drive belt tensioner clockwise.

Install the drive belt to the idler pulley (1).

NOTE

Important: Ensure the drive belt is properly aligned and seated into the grooves of the accessory drive pulleys.

Slowly release the drive belt tensioner.

Raise the vehicle.

Install the right side engine mount bracket. Refer to Engine Mount Bracket Replacement - Right Side .

Install the engine splash shield. Refer to Engine Splash Shield Replacement - Right Side .

Lower the vehicle.

Install the engine mount strut bracket. Refer to Engine Mount Strut Bracket Replacement - Right Side .

Remove the engine support fixture. Refer to Engine Support Fixture .

Install the the air cleaner assembly. Refer to Air Cleaner Assembly Replacement .
end.

It could be but how easy was the belt tensioner ? that may be the problem by not putting enough tension on the belt. How tight is the belt ?

Inspect the belt tensioner for the following conditions:
Noise

• If the belt squeals, the tensioner force may be insufficient. Check the belt length gauge, if the length is correct, replace the tensioner.
• If the tensioner clatters or rattles during engine operation, there may be internal interference or wear. Replace the tensioner.
• If the belt chirps, you may have a worn pulley or tensioner or cracks in the tensioner bas or arm. Check the mounting bolts, if they are okay, replace the tensioner.

Sticking or Seized Tensioner or Idler

• If the tensioner does not operate smoothly or doesn't move, you may have: internal thrust surface damage/wear, internal damage/wear, or a broken spring, replace the tensioner.

Appearance

• Inspect the tensioner arm for cracks or other damage. If the tensioner is broken, it should be replaced.
• Look for excessive tensioner movement at idle, which can indicate internal wear, an out-of-round pulley or loose mounting bolts. Check the mounting bolts, it they are in good condition, replace the tensioner.
• Make sure the tensioner is not tilted or misaligned. Also make sure a gap exists between the tensioner arm and base. If you notice a problem, check the mounting surface, it the surface is okay, replace the tensioner.

Belt Tracking

• If the belt does not track properly on the pulley tracking surface, you'll need to troubleshoot the problem. Check the mounting bolts and the system alignment. Then, make sure the correct belt is being used for the vehicle. If all of these things are intact, replace the tensioner.

Belt Length Indicator

• A belt length indicator is built into each tensioner.
• The gauge identifies the effective operating range of the tensioner.
• It consists of a pointer and either two or three length marks.
  • On a three-mark gauge minimum belt length, maximum belt length and ideal belt length are indicated.
  • On a two-mark gauge only minimum belt length and maximum belt length are indicated.
  • Ideal belt length on a two-mark gauge is generally half way between the minimum and the maximum.
• When a belt wears and stretches with age the tensioner will move towards the maximum belt length to maintain proper tension.
• As the pointer nears the maximum length mark, replace the belt.

the chirping noise maybe the belt tensioner with the car running see if the tensioner is bouncing if it it replace it and replace the belt dont spray wd40 on the belt it can cause the belt to come off

You broke your serpatine belt. Needs replacing. It's a $50ish part and easy to do if you have a diagram under the hood of how the belt fits. But if it was "rattling" for a couple of weeks take it in for crying out loud. Let the mechanic look it over to make sure your lack of vechile care didn't destroy anything under the hood.....

Sounds like your belt is slipping. I would check the condition of the belt and test the Belt Tensioner.

When this idler wears out it makes a growling noise that changes with engine RPM. A Bad Idler Pulley May Wobble & Wear Out Your Serpentine Belt Prematurely. Get Rid Of That Horrible Noise & Change.

Remove the serpentine belt by using a breakover bar, ratcher or serpentine belt removal tool with the correct size socket for the pulley mounting bolt. Rotate tensioner arm to release tension. Remove the bel. Using the proper size socket, remove the tensiones mounting bolt and remove tensioner.

Before installing the new tensioner, make sure the mounting surface for the tensiones is clean and free rust or other obstructions. Find the locator pin hole and rotate the replacement tensiones until the locator pin and the hole line uo. Insert the pin into the hole. Reinstall the mounting bilt and torque down to tight fit.

Rotate the tensioner arm to install the serpentine belt. Make sure the belt is correctly fitted to all pulley in the drive system. Start the engine to check for any problems. Extreme care should be taken when reinstalling the serpentine belt because some of the pulleys are located in remote positions ans it is very hard to see that belt is seated properly in all of the grooves. If the belt isn't seated properly, the belt can "ride out" of the grooves and the belt can be damaged.

Also must review the ZJ Repair Manual Secc-7-Cooling-System for graphics references.

Hope helped with this. Remember rated this help. Good luck.

So when you turn off the air con the noise stops ..
If yes then its the bearings in the Air Con pump which is driven by the same belt and when turning the r13 coolant around the bearings being dry and worn out will start to make the noise Same as the water pump does when it goes, but yours is Air Con Pump.
DONT TAKE IT OFF YOUR SELF. RON

check your belt tension. Tighten it up and the noise should go away. if not, replace the belt and tension it accordingly.

The noise is most likely the serpentine belt. Check it's condition and that of the belt tensioner. It sounds like the belt is slipping, causing the squealing noise u describe. As the belt warms up, it's getting a better 'grip' and the noise stops. Turning on the heat also turns on the a/c in newer cars, this added drag on the belt (one more component to turn, the a/c compressor) would explain why it happens when u turn on the heat. Is the belt original? If yes, it's time to change it, and check the belt tensioner to make sure it's doing it's job of keeping the belt snug on all the pulleys. Let me know how u make out.