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Questions and Answers

Ford Taurus Knocks On Acceleration

Q. I have a 2001 Ford Taurus Wagon, 3.0 liter V-6 six flex fuel engine, automatic transmission and about 63,000 miles. A mechanic described my situation as spark knock and recommended a higher octane of 89 and see if it goes away.
Ford Taurus Knocks On Acceleration

After a tank and a half, it is getting better. Even when the spark knock was bad, sound is like marbles flying around when accelerating at 2,000 RPMs, it felt smooth and no Check Engine Light.

I am trying to understand why and whether I am just postponing a needed repair or can this higher octane really solve the issue. Also if it does solve it, am I stuck on it or will it clean deposits, or something else, that allow me to return to 87 octane.

While I am comfortable under the hood of my 1971 Plymouth Duster and its slant 6 engine, the era of the sensors have me quite confused. My Taurus has been able to run 87 octane since it was new. However 89 Octane seems to have significantly reduced the recent knocking? Would 92 octane be even better?

Doesn't this indicate something is causing the timing to be off or a part that needs to be replaced? With my old Duster a tune-up with new wires, plugs, distributor cap, points, and rotor would address most everything. The Taurus has plugs, wires and all kinds of sensors. I suspect the solution is not as simple as doing a tune up in advance of the factory scheduled maintenance.

I appreciate any insight as to what I should be concerned with and what I should not, regarding the spark knock.


A. Ford has a TSB out for this problem.

Article No.: 02-24-3
Date: 12/09/02

  • Driveability - Spark Knock On Acceleration - 3.0 liter 2v/FFV Engine Only
  • Transaxle - AX4N/AX4S - Harsh Transmission Engagement - 3.0 liter 2v/FFV Engine Only

2000-2001 Taurus
1999-2000 Windstar

2000-2001 Sable

Article 00-25-5 is being republished in its entirety to update the Service Procedure.

Some vehicles equipped with the 3.0L 2V or 3.0L FFV engine may exhibit spark knock during light accelerator tip in or heavy acceleration. 2001 2V and FFV Taurus/Sable vehicles may also exhibit a harsh Park to Drive engagement. This may be caused by the calibration of the Powertrain Control Module (PCM).

Verify condition. Check for potential lean contributors, reprogram the Powertrain Control Module (PCM), and/or perform Octane Adjust. Refer to the following Service Procedure for details.

This is something the Ford Dealer will have to do. Eligible under the provisions of the bumper to bumper warranty coverage and emissions warranty. If it's out of warranty, Ford may consider covering it under a Good Will warranty.

Additional Information provided courtesy of AllDATA and Warranty Direct

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© 2006 Vincent T. Ciulla

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