4.2L Knocking under load

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Nov 21, 2010 | 03:14 PM

F16and117DCC

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4.2L Knocking under load

Hey folks, Love the forums and all of the great info on the site and it has helped me more than you know. I have an issue that I can't figure out. I have a 2001 F-150 XLT with a 4.2L auto. with about 112k on it. Recently i have heard the engine knocking/pinging under a load between 2nd and 3rd and then goes away after dropping into overdrive. I recently changed the plugs with motorcraft plugs and wires. Today I changed out the Coil pack and test drove it and the knocking is still there.

Any one have any idea as to what I might need to do next??? Any insight would be much appreciated.

Nov 23, 2010 | 04:44 PM

F16and117DCC

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Anyone have any ideas on this one??? any help would be much appreciated.

Nov 23, 2010 | 06:51 PM

randy6800

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It could be a faulty knock (detonation) senor, I have the same yr truck and engine and the part is around 45 bucks at Advance Auto.

Nov 25, 2010 | 08:23 PM

ottawaguy

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Joined: Jan 2008

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From: Gatineau, Quebec

I just mentioned this in another thread.....
Check the linkage rods on the intake manifold runners. I had one pop off and the engine on my truck and it pinged like my old 2.6 Mitsubishi I had in a caravan many years ago.
Found the linkage disconnected. They are held in with little plastic clips. These break down over time and eventually no longer hold the rods in place.
They are a pain to get to but if you reach down behind the intake manifold you should be able to feel them.
Let us know if that works...