MIL ON - DTC P0300 Through P0306 (Misfires)/Overheating

Classification:
LC99-001

Reference:
NTB99-015

Date:
April 1, 1999

1996-98 PATHFINDER ENGINE DAMAGE, MIL ON (P0300 THROUGH
P0306) AND/OR ENGINE OVERHEAT DUE TO COOLANT LEAK FROM
INTAKE COLLECTOR

APPLIED VEHICLE:
1996-98 Pathfinder (R50)

SERVICE INFORMATION

If a 1996-98 Pathfinder exhibits coolant loss, engine damage, MIL ON (P0300 through P0306) and/or engine overheat, the cause may be an intake collector coolant leak. Coolant may have leaked from the internal coolant passages of the intake collector into the intake air stream due to a casting flaw.

Coolant may also have leaked externally between the L-shaped coolant fitting and the collector due to an insufficient press fit of these two components.

In either case, a new intake collector is now available to resolve the incidents if either has occurred.

SERVICE PROCEDURE

Confirm the incident as follows:

External Intake Collector Coolant Leak Inspection





Inspect the L-shaped coolant fitting, that is pressed into the intake collector near the EGR valve (see Figure 1), for coolant leaks and/or green residue.

A. If coolant is leaking and/or green residue is present, replace the intake collector with the assembly listed in Parts Information. Refer to the appropriate section of the applicable service manual for the intake collector replacement procedure.

B. If coolant is not leaking and/or green residue is not present, perform the "Internal Intake Collector Coolant Leak Inspection" procedure listed below.

Internal Intake Collector Coolant Leak Inspection





1. Disconnect two vacuum hoses from the intake collector at the number six intake runner (see Figure 2).

A. If engine coolant and/or green residue is present in the vacuum hoses or fittings, replace the intake collector with the assembly listed in Parts Information. Refer to the appropriate section of the applicable service manual for the intake collector replacement procedure.

B. If engine coolant and/or green residue is not present, proceed with step 2.





2. Disconnect the air intake duct hose from the throttle body housing (see Figure 3) and look inside the intake collector for signs of coolant.

A. If coolant and/or green residue is present inside the intake collector, replace the intake collector with the assembly listed in Parts Information. Refer to the appropriate section of the applicable service manual for the intake collector replacement procedure.

B. If coolant and/or green residue is not present inside the intake collector, proceed with step 3.

3. Apply pressure to the cooling system for 30 minutes, then look inside the intake collector for signs of coolant.

CAUTION:
Coolant can enter the cylinders when applying pressure to the cooling system if an internal intake collector leak exists. Therefore, after the pressure test, remove the spark plugs and crank the engine to ensure all coolant is expelled from the cylinders.

WARNING:
When cranking the engine with the spark plugs removed, fluid can come out of the open spark plug holes under pressure. Wear suitable eye and body protection.

A. If the cooling system pressure drops and coolant is found inside the intake collector, replace the intake collector with the assembly listed in Parts Information Refer to the appropriate section of the applicable service manual for the intake collector replacement procedure.

B. If the cooling system pressure does not drop and coolant is not found inside the intake collector, look for other causes of the incident.

PARTS INFORMATION

DESCRIPTION PART NUMBER QTY

Collector Assembly 14010-1W660 1





CLAIMS INFORMATION