2002 Ford 500 Repair Question
Preignition knock
Their best guesse was bad gas. I've changed brand/gas station and have run a half tank of premium through it and while the knock has diminished, it is still there. What could be causing this problem?
Asked by hopk6344Answer
Suspect EGR the operation system may have checked out but passage ways maybe blocked with carbon. Need to remove EGR inspect and clean.EGR must operate or knock will occur
I will double-check, but I think they took the egr valve off and checked the passage ways to make sure they were unobstructed. I remember the tech saying that could be a problem when I dropped the van off for diagnostics.
I just checked with the tech - they did NOT do a physical inspection of the passages. They pulled the sensor data and the flow sensor showed full flow - indicates no obstruction.
That just means flow of vacuum not exhaust gas into intake
DOC,
COULD TIMING, OR SLOP IN THE TIMING HAVE THE SAME AFFECT?
I FEEL SURE ON THIS RIG, "ADVANCE" IS ELECTRICALLY CONTROLLED, NOT VACUUM---PRONE TO NON-WORKING MECHANICAL PARTS, LIKE IN OLDER VEHICLES.
THE MEDIC
Could also be the knock sensor not retarding the timing when engine is detonating or engine is overheating and type of fuel use
Found Technical Service Bullitin REF> 04-19-2 that is a reflash for PCM to adjust Octane to control knock. Bummer is dealer would have to do
Well, my mechanic flushed the fuel injectors and the combustion chamber to remove carbon, still getting the preignition. next on the list is to do a physical inspection of the EGR ventilation passageways. Also, found out that this year of ford does not have a knock sensor. If this doesn't work, what would you recommend?
The timing chain/belt (whatever it uses) and the sprocket was replaced 30 thousand miles ago. (about 3 years ago).
mechanic said the ventilation passages were clear, but found a problem with the EGR control solenoid. Could this be causing the problem? also, wouldn't that cause an error code on the computer?