Northstar Engines and System Technical Discussion Discussion, EGR symptoms in Cadillac Engine Technical Discussion; What are the symtoms of a sticking egr, car is surging a little new coils could possibly be a fouled ...
Automobile(s): 2002.5 F55 STS/64500mi, 2004 Ford F150 SuperCab4x4
MD Eastern Shore - Kent Island
Re: EGR symptoms
Another symptom of a sticky EGR valve is a brief, minor ignition "rattle" on part-throttle acceleration or a low pitched ignition ping during moderate part-throttle such as going up a slight grade. And, as Ranger said, a partly open EGR will trash the idle characteristics.
It is entirely possible that a surge could be present also, as when EGR operates it dilutes the incoming air (oxygen) charge in order to control combustion temperatures: excess exhaust gas from a fluttering EGR would upset the fuel/air mixture.