Problem Reports

The AC/heater (HVAC) system may unexpectedly switch to the defrost mode when accelerating. This system is operated by engine vacuum and should be inspected for any vacuum leaks if this problem develops.  There is also a revised vacuum check valve available to address this concern.

The blower motor may operate erratically and the blower switch operation has a sticky or mushy feeling, the detents almost non existent. Our technicians tell us that the blower switch should be removed and inspected for overheating. This is common if the blower motor is frequently operated on high speed as the current flow through the switch tends to melt internal the components. Also carefully inspect all of the switch connector terminals for discoloration due to overheating and replace as required. A poor electrical contact at the connector will also cause the switch to overheat.

On the 3.9L V6, 5.2L V8 and 5.9L V8 the Oil leaks commonly from the valve cover gaskets, intake manifold gaskets (front and rear), timing cover gaskets, distributor O-ring, and the rear main seal area. Using fluorescent engine oil dye can be helpful in determining the source(s) of the oil leak.

On the 3.9L V6 and 5.2L V8, rerouting the ignition coil wire and spark plug wires can help solve a misfire and/or surge problem that occurs at approximately 45 mph. A service bulletin was published that outlines the specifics of the repair. It states the rerouting procedure should be performed before other repairs are done for misfires, surging or spark knock.

An intermittent connection in the crank position sensor wire connector can cause poor engine performance or the engine may crank but not start.

The door glass may separate from the glass lift channel. Our technicians tell us a front door glass channel kit is available to repair the door glass. The repair involves removing the door glass from the vehicle.

On 3.9L V6 and 5.9L V8 engines, the intake manifold gasket may leak and cause increased oil consumption and a spark knock during acceleration; the gasket should be replaced.

On the 3.9L V6 and 5.9L V8 the engine oil leaks at the distributor can be misdiagnosed as leaks from the intake manifold seal, oil pan gasket, or rear crankshaft (rear main) seal. A revised distributor is available if oil is found inside the distributor.

Leak detection pump failure can be caused by the internal diaphragm switch sticking, or in some cases, contamination from debris or carbon particles from vapor canister. If black carbon particles are present in the LDP, replace vapor canister in addition to LDP. The purge solenoid should also be checked for debris or carbon contamination and replaced as necessary. All evap system hoses are subject to cracking and splitting causing leaks, Inspect hoses carefully. In cases of contamination from carbon particles or debris, all hoses and tubes must be blown out with compressed air to remove contaminates.