1991 Ford Explorer WHAT SHOULD BE CHECKED NEXT?

1991 FORD EXPLORER

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1991 Ford Explorer 4 cyl Four Wheel Drive Manual

HAVE A 1991 FORD EXPLORER WITH A 1995 USED ENGINE.5 SPEED MANUAL TRANSMISSION.4.0 LITER V.6..RECENTLY WHILE ON AN EXTENDED TRIP THE ENGINE OVERHEATED. i STOPPED THE VEHICLE LET IT COOL AND ADDED WATER WHILE IT WAS RUNNING.THE SERPENTINE BELT KEPT COMING OFF SO WE REPLACED THE WATER PUMP AND SERPENTINE BELT.REFILLED FLUIDS.WAS ABLE TO DRIVE BUT EXPERIENCED NO HEAT FROM THE HEATER AND BECAME OVERHEATED AGAIN.NOW IT SEEMS TO HAVE SLUDGY OIL TYPE SUBSTANCE IN RADIATOR AND NO HEATER.VEHICLE STILL RUNS AND DRIVES WITH NO CLANKING OR BANGING AS WOULD BE WITH BLOWN ENGINE.WHAT SHOULD BE DONE NEXT FOR OVERHEATING,NO HEATER AND SLUDGY SUBSTANCE IN RADIATOR?iS ENGINE BLOWN?

Dec 6, 2008 at 4:09 AM

DAVE H

CERTIFIED EXPERT
13,384 POSTS

your head gasket has blown and you need to replace it i'm afraid .. you should really have the head pressure tested once you have removed it to check it is not cracked or warped ?? CYLINDER HEAD Removal Disconnect negative battery cable. Drain cooling system. Release fuel pressure. See FUEL PRESSURE RELEASE . Remove upper and lower intake manifolds. See INTAKE MANIFOLDS . Remove exhaust manifold. See EXHAUST MANIFOLDS . Remove valve covers. See VALVE COVERS . Remove spark plugs. Remove accessory drive belt. If removing left cylinder head, remove A/C compressor (if equipped). Remove power steering pump and bracket, and position aside. If removing right cylinder head, remove alternator and bracket. On all cylinder heads, remove rocker arm shaft bolts evenly by loosening bolts 2 turns at a time. Remove rocker arm shaft assembly. CAUTION:If rocker arm shafts are not loosened gradually, shafts may become bent or damaged. Mark push rod location for installation reference, and remove push rods. Remove and discard cylinder head bolts. Remove cylinder head(s) and gaskets. Inspection Check dowels in cylinder block and replace if necessary. Check cylinder head warpage. Resurface cylinder head if warpage exceeds specification. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. DO NOT machine more than .010" (.25 mm) from original cylinder head surface. CAUTION:Always use NEW cylinder head bolts when installing cylinder heads. Installation Ensure all bolt holes in cylinder block are clean. Install gaskets and cylinder heads. Install NEW cylinder head bolts. Tighten cylinder head bolts in sequence to specification in Step 1. Refer to Fig. 4 . See TORQUE SPECIFICATIONS . Install lower intake manifold. See INTAKE MANIFOLD . Tighten lower intake manifold bolts to Step 1. See TORQUE SPECIFICATIONS . Tighten cylinder head bolts to Step 2. Tighten lower intake manifold bolts to Step 2. See TORQUE SPECIFICATIONS . Tighten cylinder head bolts to Step 3. Tighten lower intake manifold bolts to Steps 3 and 4. See TORQUE SPECIFICATIONS . Coat push rods with Oil Conditioner (D9AZ-19579-CA) and install in original position. Install rocker arm shaft assembly to cylinder head. Guide rocker arms onto push rods. Tighten rocker arm bolts evenly to specification. To complete installation, reverse removal installation. Fill and bleed cooling system. See COOLING SYSTEM BLEEDING . Fig. 4: Cylinder Head Bolt Tightening Sequence Courtesy of FORD MOTOR CO.

Dec 6, 2008 at 6:13 AM