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.

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.

Battery acid may leak onto an ABS wiring connector which could cause corrosion or a short circuit. A revised battery tray is available to protect the wire harness. Any damaged wiring will need to be repaired as necessary.

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.