2004 Freestar 3.9 pinging
#1
09-06-2016, 10:00 AM
2004 Freestar 3.9 pinging
I'm stumped...I got a 2004 Freestar 3.9L last October, w/157k miles. It ran decent at the time, and was OK for a few months.
The upper intake manifold gaskets were replaced right before I got it. It had an EGR code, and the EGR valve was installed with a used one, which turned out to be aftermarket.
I've had a few of the typical issues--broken plastic bushings on the intake manifold runner control rods, water in the PCM, camshaft synchronizer--but nothing out of the ordinary. I took care of those, and changed the spark plugs while I had it apart to do the cam synchronizer.
I have a continual problem with spark knock/pinging. It doesn't do it all the time. It's under lighter throttle, lower RPM, under load--like going up a hill in OD or 3rd, below 3,000 RPM, less than maybe half throttle. You have to drive it a while before it starts. When it's really bad, it will even ping a little as you start up from a stop sign. You can hear it sometimes even going down the highway, as the cruise opens the throttle a little to maintain speed going up a slight incline.
It may be my imagination, but it seems to be worse when the temperature is a little cooler (less than 85, this summer) and right after I've filled the tank. I tried higher octane, and it didn't make any difference. Different brands of gas didn't do anything either.
I also think it idles a little slow, esp. w/the AC on (no more than 600, and it's slow enough it shakes some).
So far,
--made sure the intake manifold runner actuator is adjusted so the valves are closed
--dealer checked codes; no DTCs stored, and no software upgrades available
--mechanic checked for vacuum leaks w/smoke machine; all OK
--replaced rubber PCV boots on line between valve cover and intake manifold
--replaced the fuel filter, and ran injector cleaner through it (the filter was filthy)
Where else do I check? Did I damage a spark plug once when it had water in the PCM and ran terrible, or when an intake manifold runner bushing broke? I can't really afford to hand it to the dealer, and say "Find it".
Thanks for your patience in getting through this post.
The upper intake manifold gaskets were replaced right before I got it. It had an EGR code, and the EGR valve was installed with a used one, which turned out to be aftermarket.
I've had a few of the typical issues--broken plastic bushings on the intake manifold runner control rods, water in the PCM, camshaft synchronizer--but nothing out of the ordinary. I took care of those, and changed the spark plugs while I had it apart to do the cam synchronizer.
I have a continual problem with spark knock/pinging. It doesn't do it all the time. It's under lighter throttle, lower RPM, under load--like going up a hill in OD or 3rd, below 3,000 RPM, less than maybe half throttle. You have to drive it a while before it starts. When it's really bad, it will even ping a little as you start up from a stop sign. You can hear it sometimes even going down the highway, as the cruise opens the throttle a little to maintain speed going up a slight incline.
It may be my imagination, but it seems to be worse when the temperature is a little cooler (less than 85, this summer) and right after I've filled the tank. I tried higher octane, and it didn't make any difference. Different brands of gas didn't do anything either.
I also think it idles a little slow, esp. w/the AC on (no more than 600, and it's slow enough it shakes some).
So far,
--made sure the intake manifold runner actuator is adjusted so the valves are closed
--dealer checked codes; no DTCs stored, and no software upgrades available
--mechanic checked for vacuum leaks w/smoke machine; all OK
--replaced rubber PCV boots on line between valve cover and intake manifold
--replaced the fuel filter, and ran injector cleaner through it (the filter was filthy)
Where else do I check? Did I damage a spark plug once when it had water in the PCM and ran terrible, or when an intake manifold runner bushing broke? I can't really afford to hand it to the dealer, and say "Find it".
Thanks for your patience in getting through this post.
#2
09-06-2016, 01:01 PM
Usually when an engine starts to ping on acceleration a good part of the time the EGR system is not functioning correctly.
Might be a good idea to remove the EGR valve and confirm that the ports are not clogged with carbon. If the vehicle has an aluminum DPFE sensor consider replacing it with the later type made of plastic which is more durable.
Might be a good idea to remove the EGR valve and confirm that the ports are not clogged with carbon. If the vehicle has an aluminum DPFE sensor consider replacing it with the later type made of plastic which is more durable.
#3
09-06-2016, 01:34 PM
Usually when an engine starts to ping on acceleration a good part of the time the EGR system is not functioning correctly.
Might be a good idea to remove the EGR valve and confirm that the ports are not clogged with carbon. If the vehicle has an aluminum DPFE sensor consider replacing it with the later type made of plastic which is more durable.
Might be a good idea to remove the EGR valve and confirm that the ports are not clogged with carbon. If the vehicle has an aluminum DPFE sensor consider replacing it with the later type made of plastic which is more durable.
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