NHTSA Complaint #10356757 — 2007 FORD EXPLORER

2007 FORD EXPLORER MAKING A LOUD ROARING SOUND UPON ACCELERATION. I FINALLY GOT IT TO DO IT AT THE DEALER. THE SERVICE MANAGER, LEAD TECH AND MYSELF WENT FOR A RIDE. THEY AGREED THAT THE FAN CLUTCH WAS LOCKING UP AND FELT THAT A SIMPLE R&R WOULD FIX IT. HOWEVER AT THE LAST MINUTE THE SERVICE MANAGER DECIDED TO CALL FORD ENGINEERING AND HE TALKED TO AN ENGINEER WHO EXPLAINED THAT THE FAN CLUTCH IS CONTROLLED BY THE PCM (MODULE) AND THAT REPLACING THE FAN WOULD NOT SOLVE THE ISSUE. HE EXPLAINED THAT FOR SOME REASON THE PCM THINKS THE ENGINE IS OVERHEATING AND IT IS TRYING TO INCREASE AIR FLOW THROUGH THE RADIATOR. MAKES SENSE. HOWEVER THERE ARE NO CODES SHOWING AN OVERHEATING PROBLEM. HMMMM'' UPON FURTHER INVESTIGATION IT WAS FOUND THAT THE TRANS WAS THROWING OF AN OVERHEAT CODE! I'M NOT SURE WHY THAT WAS NOT APPARENT FROM THE BEGINNING. THE LAPTOP SHOWED THE TRANS TEMP AT 270!. NO WAY! SO UP ON THE LIFT, AND PHYSICALLY CHECK THE TRANS TEMP AND FLUID TEMP. WELL, 160 ALL DAY LONG! TURNS OUT THAT THE THERMO BYPASS WAS FAULTY AND WAS MISINFORMING THE PCM THAT THE TRANS WAS OVERHEATING AND THE PCM WAS LOCKING UP THE FAN CLUTCH TO PULL MORE AIR TO COMPENSATE. REPLACED THE THERMO BYPASS AND SO FAR PROBLEM SOLVED. TO DO THIS YOU MUST DROP THE TRANS PAN AND REMOVE THE VALVE BODY AS THE THERMO BYPASS IS LOCATED IN THE VALVE BODY. *TR