Head bolt and head gasket failure with coolant loss
ENGINE AND ENGINE COOLING
4 NHTSA complaints · 2003-05 → 2008-04
“CADILLAC 4.6 ENGINE FAILURE DUE TO HEAD BOLT PROBLEM THE THREADS PULL OUT OF BLOCK CAUSING COOLANT LEAKS AND COOLING SYSTEM PRESSURE AND LOST”
“THE LOW COOLANT INDICATOR WOULD ILLUMINATE AND THE CONTACT CONSTANTLY HAD TO REFILL THE COOLANT RECEPTACLE”
“VEHICLE BEGAN TO LOSE COOLANT, BUT WASN'T SEEING ANY LEAKS”