2004 HYUNDAI XG 350 Engine And Engine Coolingengine Problems

I'M A SINGLE MOM AND HAVE NO FAMILY HERE IN CT. TO HELP ME OR GUIDE ME IN THIS SORT OF THING. MY CAR STARTED MAKING A KNOCKING NOISE UNDER THE HOOD. I DIDN'T KNOW WHAT IT WAS SO I TOOK IT TO MY MECHANIC. IT TOOK A COUPLE OF DAYS BEFORE SOME ONE THERE COULD LOOK AT IT. HE TOLD ME IT WAS AN ENGINE KNOCK AND SAID I SHOULD TAKE IT BACK TO THE DEALERSHIP TO GET IT FIXED. BY THE TIME I CONTACTED KEY IN MILFORD CT, MY CAR WAS OUT OF WARRANTY BY EIGHT DAYS. AND THAT'S ALL THEY KEPT TELLING ME. KEEP IN MIND, I BROUGHT THE CAR TO MY MECHANIC THE DAY BEFORE THE WARRANTY EXPIRED. KEY CHARGED ME 105.00 TO DETERMINE IT WAS IN FACT AN ENGINE KNOCK,AFTER I TOLD THEM MY MECHANIC TOLD ME WHAT IT WAS. KEY HAD NO LOANER CAR...

DT*: THE CONTACT STATED THE VEHICLE INTERMITTENTLY LOST POWER WHILE DRIVING AT SPEEDS ABOVE 40MPH. THE VEHICLE RESUMED POWER AFTER BROUGHT TO A STOP. THE ONLY WARNING INDICATOR IS THE TCS LIGHT FLASHING DURING THE REDUCTION OF SPEED. THE VEHICLE WAS TAKEN TO A SERVICE DEALER TWO MONTHS AGO AND THE DEALER REPLACED THE FUEL PUMP, FILTER AND LINES. THE PROBLEM BECAME WORSE AND THE VEHICLE WAS RETURNED TO THE DEALER WHO RECOMMENDED GETTING A WHEEL ALIGNMENT AND TIRE ROTATION. THIS WAS COMPLETED AT AN INDEPENDENT REPAIR SHOP, BUT THE PROBLEM CONTINUES. THE VEHICLE HAS NOT BEEN RETURNED TO THE DEALER FOR FURTHER INSPECTION.