Intake Manifold Expansion Plug - Coolant Leak

Reference:
ITB99-011

Classification:
LC99-004

Date:
April 1, 1999

TITLE:
1999 G20 COOLANT LEAK FROM INTAKE MANIFOLD EXPANSION PLUG

APPLIED VEHICLE:
1999 G20 (P11)

APPLIED VIN:
Vehicles built before JNKCP11A1XT012400

APPLIED DATE:
Vehicles built before November 5, 1998

SERVICE INFORMATION

If a 1999 G20 exhibits coolant leaking under the front passenger side of the vehicle, the cause may be the expansion plug located on the lower portion of the intake manifold (passenger side). Coolant may leak between the expansion plug and the intake manifold sealing surface due to mis-installation (at the factory) of the expansion plug.

A new intake manifold is now available to correct this incident. Use the following service procedure to repair the vehicle.

NOTE: The intake manifold assembly consists of two parts. An upper part, which is referred to as "intake manifold collector" and a lower part referred to as "intake manifold". These terms will be used in the following service procedure.

SERVICE PROCEDURE





1. Inspect the intake manifold expansion plug (see Figure 1) for coolant leaks and/or green residue.

A. If coolant is NOT leaking and/or green residue is NOT present, look for other causes of the incident.

B. If coolant is leaking and/or green residue is present, replace the intake manifold with the assembly listed in Parts Information using the following service procedure.

2. Record radio station pre-sets.

3. Turn the ignition key to the OFF position.

4. Disconnect the negative cable from the battery.

5. Drain the engine coolant into a suitable container.

6. Remove the air intake hose and the top half of the air cleaner housing.





7. Remove the vacuum hose support bracket from the intake manifold collector (see Figure 2).

8. Remove the Automatic Speed Control Device (ASCD) and throttle cables from the intake manifold collector.





9. Remove the two support brackets from the intake manifold collector (see Figure 3).

10. Disconnect all hoses and wire harness connectors from the intake manifold collector.

NOTE: Do not remove the EVAP canister purge volume control valve or the balance hoses from the intake manifold collector (see Figure 3).

NOTE: Mark all hoses and wire harness connectors for correct re-installation.

11. Remove the power steering hose support bracket from the intake manifold collector.





12. Remove the top bolt of the intake manifold collector/Back Pressure Transducer (BPT) valve support bracket from the intake manifold collector (see Figure 4).

13. Remove the nuts that secure the intake manifold collector.

14. Lift up the intake manifold collector and disconnect the wire harness from the air regulator valve.

15. Remove the intake manifold collector.

16. Place a piece of tape over the open ports of the intake manifold to prevent foreign matter from entering the engine.

17. Disconnect the wire harness from the fuel injectors and re-position the harness towards the engine room wall.

NOTE: The wire harness for the fuel injectors also connects to the detonation sensor (located below the intake manifold on the engine block). This wire harness will be disconnected from the detonation sensor later (step 34).

18. Remove three bolts and remove the fuel injector rail from the intake manifold. Position the injector rail on the driver's side inner fender well.

WARNING: Do not disconnect the fuel supply hose or the fuel return hose from the injector rail.





19. Remove the fuel injector seals/insulators from the intake manifold (see Figure 5).

NOTE: Place tape over each fuel injector opening to prevent foreign matter from entering the engine.

20. Remove the BPT valve and support bracket.

NOTE: Mark the BPT valve hoses for correct re-installation.

21. Disconnect the Exhaust Gas Recirculation (EGR) tube from the EGR valve.





22. Remove the EGR temperature sensor from the intake manifold (see Figure 6).

23. Loosen (but do not remove) the power steering pump adjustment bolt.

24. Remove the drive belt from the power steering pump pulley.

25. Remove the nuts that secure the support bracket to the lower rear portion of the intake manifold.





26. Raise the vehicle and remove the bolts that secure the intake manifold support bracket to the engine block (see Figure 7).





27. Remove the passenger side lower intake manifold support bracket (see Figure 8).





28. Remove three bolts and remove the power steering pump mounting bracket (see Figure 9).

29. Position the power steering pump rearward to gain access to the oil filter housing mounting bolts.

NOTE: Do not disconnect the hoses from the power steering pump.

30. Disconnect the wire harness from the oil pressure switch (see Figure 9).

31. Remove four bolts and maneuver the oil filter housing to remove it from the engine block (see Figure 9).

NOTE: Cover the engine block inlet and outlet oil holes to prevent foreign matter from entering the engine.

32. Lower the vehicle and remove the large coolant hose from the intake manifold.

33. Remove the nuts/bolts that secure the intake manifold to the cylinder head.

34. Re-position the intake manifold to disconnect the wire harness from the detonation sensor.

NOTE: The detonation sensor is located below the intake manifold on the engine block.

35. Remove the intake manifold from the vehicle.

36. Remove the EGR valve from the old intake manifold and install the EGR valve on the new intake manifold. Tighten the EGR mounting bolts to 21 - 26 N.m (2.1 - 2.7 kg-m, 15 - 20 ft-lb).

NOTE: Use a new gasket when installing the EGR valve. Refer to Parts Information.

37. Transfer the engine coolant temperature sensor and thermal transmitter as follows:

A. Remove the engine coolant temperature sensor and thermal transmitter from the old intake manifold.

B. Clean the threads of the engine coolant temperature sensor and thermal transmitter and apply RTV silicone sealant (such as Loctite Ultra Blue P/N 587 or equivalent).

C. Install the engine coolant temperature sensor and tighten it to 20 - 29 N.m (2.0 - 3.0 kg-m, 14 - 22 ft-lb).

D. Install the thermal transmitter and tighten it to 20 - 26 N.m (2.0 - 2.7 kg-m, 14 - 20 ft-lb).





38. Transfer four mounting studs from the old intake manifold to the new one (see Figure 10).

NOTE: Avoid damaging the studs by using the "double-nut" method to remove and install the studs.

39. Re-install the intake manifold/collector in the reverse order they were removed. Refer to the following notes when re-installing these components.

NOTES:

^ Refer to the appropriate section of the 1999 G20 Service Manual for tightening torque specifications.

^ Use a new gasket when assembling the intake manifold to the intake manifold collector. Refer to Parts Information.

^ Use a new gasket when installing the intake manifold/collector assembly to the cylinder head. Refer to Parts Information.

^ Use new seals/insulators when re-installing the fuel injector rail. Refer to Parts Information.

^ Use new O-rings when re-installing the oil filter housing. Refer to Parts Information.

^ Make sure all hoses and wire harness connectors are re-installed in their original locations.

^ Adjust the power steering pump belt tension to specification. Refer to the appropriate section of the 1999 G20 Service Manual for the belt tension specification.

40. Check engine oil and coolant levels. Add as needed.





PARTS INFORMATION





CLAIMS INFORMATION