The intake manifold gaskets can develop external engine oil or coolant leaks. The intake manifold will need to be removed and the gaskets replaced to correct this issue. In some cases the plastic intake manifold my be damaged requiring replacement.
Problems for specific Pontiac Bonneville years:
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Most reported 1999 Pontiac Bonneville problems
The mode and temperature door actuators may fail causing improper air flow or temperature output from the heating and AC (HVAC) system.
The transmission pressure control solenoid may fail causing erratic shifting. Our technicians tell us that partial dis-assembly of the transmission is necessary to replace a failed pressure control solenoid.
The high pressure power steering hose will commonly leak fluid; it should be replaced.
The rubber section of an automatic transmission cooler line may develop a fluid leak . In some cases the leaking section of hose can be replaced. In others, the complete cooler line must be replaced to correct this concern.
Illumination of the Check Engine Light can be caused by a loose or worn gas cap.
Problems with the anti-theft systems using the raised-chip key can prevent the car from starting. The wires in the steering column to the ignition lock cylinder tend to break. The the key and ignition lock cylinder must be replaced to correct this condition.
The outer tie rod ends on the steering linkage may wear causing excessive free play in the steering and uneven tire wear. If the worn tie rod ends are replaced, the wheel alignment should be checked and adjusted as necessary.
The front struts may show signs of wear, or be excessively bouncy ride at freeway speeds. This may begin to occur at around 75,000 miles.