Cadillac Repair: 96 SLS CADILLAC, time serts, coolant level

Question
I AM IN THE PROCESS OF PURCHASING A 96 SLS W/ THE 32V NORTHSTAR MOTOR.  THE CAR IS A ONE OWNER W/ 66K MILES AND IN GREAT CONDITION.  THE CAR WAS OVERHEATING, THE DEALER SAID THE WATER PUMP WAS LEAKING.  HE HAD THE WATER PUMP REPLACED.  WHEN THE AUTO SHOP RAN A PRESSURE TEST THEY FOUND A CRACK IN THE RADIATOR.  THAT WAS REPLACED AND WHILE REPLACING THAT THEY REPLACED THE THERMOSTAT.  DRIVING THE CAR HOME (ABOUT 90 MILES) THE CAR DID NOT OVER HEAT YET BUT THE CHECK COOLANT LEVEL CAME ON.  THE CAR WAS FULL OF COOLANT WHEN I LEFT AND AFTER 40 MILES IT NEEDED A FULL GALLON OF COOLANT TO GET IT BACK TO FULL.  I FILLED IT UP AND THEN CONTINUED ON.  ABOUT 4 MILES FROM MY FINAL DESTINATION THE CHECK COOLANT LEVEL CAME ON AGAIN AND THEN THE CAR BEGAN TO HEAT UP.  I HAD TO PULL OVER AND LET IT COOL DOWN, WHEN IT DID I FINISHED DRIVING TO MY DESTINATION.  I LET IT COOL DOWN AND THEN REFILLED THE RADIATOR AND IT TOOK ABOUT 1.5 GALLONS.  WHILE DRIVING BACK IT APPEARED THAT THE VEHICLE WAS SMOKING OUT THE TAILPIPES.  COULD THIS BE A HEAD GASKET, A CRACKED BLOCK OR A CRACKED HEAD.  IF SO HOW DO I FIND OUT WHAT THE PROBLEM IS BEFORE BUYING THE CAR.  THANKS

Answer
HI TIM,

     SOUNDS LIKE THIS MIGHT BE A GOOD VEHICLE TO PASS ON BECAUSE THE NORTHSTAR ENGINE DOES HAVE A PROBLEM WITH HEAD BOLT THREADS PULLING OUT OF THE BLOCK AND THEN OVERHEATING DOES OCCUR. THE FIX IS TO EITHER REMOVE BOTH HEADS AND THEN DRILL OUT ALL THE BOLT THREADS AND INSTALL TIME SERTS WHICH ARE UPDATED HELI-COILS OR REPLACE THE ENGINE WITH A NEW OR REMANUFACTURED ONE. I WOULD EXPECT YOU TO SPEND AT LEAST $5-$7,000 FOR THE ENGINE WORK BUT YOU NEED TO GET ACCURATE QUOTES FROM THE SHOP THAT WILL DO THE WORK TO GET THE REAL PRICE. IT MIGHT EVEN BE MORE LIKE $10,000 ONCE ALL IS SAID AND DONE. PLUS THE PRICE YOU WILL PAY FOR THE CAR.

     SINCE YOU NEEDED TO ADD SO MUCH COOLANT IT HAD TO GO SOMEWHERE. THE CHOICES ARE AN EXTERNAL LEAK SOMEWHERE LIKE A HOSE, RADIATOR OR WATERPUMP GASKET, INTO THE OIL PAN OR PUSHED OUT OF THE ENGINE INTO THE OVERFLOW BOTTLE AND THEN OUT OF THE BOTTLE ONTO THE GROUND BY EXHAUST GASSES FROM A BLOWN HEAD GASKET OR CRACKED HEAD. THE WAY TO TEST FOR THIS IS TO GET A LEAK DETECTION KIT WHICH CONSISTS OF A SPECIAL LIQUID, A SQUEEZE BULB AND A CYLINDER WITH A STOPPER ON BOTH ENDS. THE COOLANT IS DRAINED DOWN IN THE OVERFLOW BOTTLE. THEN THE LIQUID IS POURED INTO THE CYLINDER WITH THE BULB AT THE TOP AND IS THEN PLACED ON TOP OF THE OVERFLOW BOTTLE IN PLACE OF THE RADIATOR CAP. THE ENGINE IS STARTED AND IF YOU ARE UNLUCKY EXHAUST GASSES WILL FORCE THEIR WAY INTO THE CYLINDER AND TURN THE LIQUID FROM BLUE TO YELLOW WHICH INDICATES A LEAK. OTHERWISE YOU SQUEEZE THE BULB TO DRAW VAPORS INTO THE LIQUID WITH THE ENGINE RUNNING AND IF IT TURNS YELLOW EXHAUST GASSES ARE GETTING INTO THE COOLANT. THE TRICK IS TO DRAIN THE ANTIFREEZE DOWN FAR ENOUGH SO THAT IT DOESN'T GET INTO THE TEST LIQUID OR YOU WILL NEED TO POUR IT OUT AND START OVER WITH FRESH LIQUID. BUT IF THAT HAPPENS WITH-IN THE FIRST 5 MINUETS OF ENGINE RUNNING THEN THE ENGINE HAS PROBLEMS ANYWAY. TOTAL ENGINE RUNNING TIME MIGHT BE UP TO 30 MINUETS TO DETERMINE IF A PROBLEM EXISTS.

      THIS TEST KIT CAN BE BOUGHT AT NAPA OR OTHER BIGGER AUTOPARTS STORES. ONE THING I WOULD ADVISE IS TO HAVE A DIFFERENT SHOP DO THE TESTING THAN THE ONE YOU MIGHT BE BUYING THIS FROM SO YOU GET THE CORRECT DIAGNOSIS...NOT JUST A "ITS FINE" SO THEY GET YOUR MONEY.

      SORRY I CAN'T HAVE BETTER NEWS FOR YOU. BILL