When I shut of my truck I hear a poping noise coming from under the passenger side dash on my X. I'm wondering if there is a air pocket in the radiator system. I hear the heads leak on 99 expedition. It that true? TIA


Please respond...........People like to read but no one will help a fellow ford enthusiast out.

 

Coolant leakage from the passenger side head gasket has been an issue with many of the '99's with the 5.4l engine. There is a long thread on this subject that can be accessed by the search feature in this forum.

Re: the popping noise, is this intermittent, continuous or just occasional? One guess would be a malfunctioning vacuum motor on the climate control system if the noise is related to HVAC use and is intermittent.

Air in the coolant system generally manifests itself as a series of gurgling noises in the heater core. An intact system will self-purge introduced air. A low coolant level will also generate the same noise.