Cylinder Head - Coolant Leak At Threaded Blind Plugs

Classification: EM95-008

Reference: NTB95-087

Date: September 20, 1995

VG30E CYLINDER HEAD COOLANT LEAK AT THREADED BLIND PLUGS

APPLIED VEHICLES:

1993 - 1995 Quest (V40)
1990 - 1995 Pathfinder/Truck (WD21/D21)
1989 - 1994 Maxima With VG30E engine (J30)

SERVICE INFORMATION




If a Nissan model with a VG30E engine develops a slight coolant leak over a period of use, the coolant leak may be traced to the front area of the cylinder head and may appear to be coming from the head gasket.

SERVICE PROCEDURE

Use the following procedure for identifying and repairing the source of the coolant leak:

1. Remove the front timing belt covers, timing belt, upper camshaft timing gears and the rear belt cover/dust shield. (It is not necessary to remove and dis-assemble the cylinder head for this repair.) Prior to removing the timing belt, manually rotate the engine and align timing marks (this will ease re-assembly).

2. Inspect the threaded blind plug located directly below the camshaft. If coolant, corrosion, or a powdery residue is noticeable around the outside edges of the threaded blind plug, use a suitable Hex wrench and remove the threaded blind plug from the cylinder head.

3. Clean off all traces of coolant, sealer, and residue from the threaded blind plug and cylinder head threads.

4. Apply Teflon tape or a suitable pipe thread sealer to the threads of the threaded blind plug.

5. Re-install the threaded blind plug into the cylinder head. Torque to 50 ft. lb. +/- 2 ft. lb.

6. Re-assemble the rear belt cover/dust shield, upper camshaft timing gears, timing belt, and the front timing belt covers.

Note
Utilize the procedure found in the Engine Mechanical section of each model Service Manual to correctly time the camshafts during timing belt dis-assembly and installation. Refer to the MA section for cooling system filling and bleeding information.




CLAIMS INFORMATION