What are the symptoms of a bad egr valve in a 1995 windstar?

Answer 1

First, lets talk a little bit a bout what does an EGR system do. The EGR valve either electric or mechanic is a component part of the emission system. It was designed to let back into the running engine a very small portion of burnt gases in order to decrese the posibilities of Nitrus Oxide formation (NOX). The PCM sends a signal to the EGR valve to open it over 1500RPM so the engine wont feel the burnt gas and fail. If the gas enters the engine below 1500RPM, the engine will fail and hesitate because a small portion or burnt gases will enter the intake manifold and contaminate the air/fuel mixture and a very nasty smell will come out of the exaust pipe do to impropper combustion. Also, the manifold absolute preasure will be nearly the same as that of the ambient and would probbaly make the engine to stall. If the EGR is stuck closed, no symptoms would be felt as from the engine funtionability perspective but if we talk about an electric EGR valve, the CHECK light will turn on and the PCM will create a DTC.

Hope this helps.

Good luck