Mondeo Pinking - Dan Terry
Hello all,

Ive got a 1995 Ford Mondeo 24v ( Duratec V6 engine) with 130k miles. When the weather is warm I get quite severe pinking from 3000rpm upwards with high load ( uphill or accelerating ), this pinking seems to coincide with the opening of the secondary throttles. I maintain the car myself and it has new spark plugs, HT leads, air filter and fuel filter. Ive tried running higher octane fuel ( Shell Optimax ) and the pinking is still there. Ive checked the Intake Air Temp sensor and it gives a reading of approx 25kOhms at 20degC which seems to be OK. Also checked the EGR by applying a vacuum to the valve at idle, the engine stumbled then stalled so EGR passages are not blocked.

The MAF and Lambda sensors are the originals but passed last MOT at lambda=1.01 so I assume they are in good condition. Ive also run some Redex injector cleaner through but no improvement.

If I remove the Octane Adjust Plug the engine runs fine and doest not pink at all however I dont think this is a good solution.

Any ideas about what could cause this pinking ???? I dont know what else to check and its getting very annoying.

Any help much appreciated, esp Adam from Tune up, my email is
Mondeo Pinking - Peter D
Pinking from 3K up on load. Bit strange !! Check the static and dynamic timing is OK. Not sure 25K is ok for sensor sounds far to high to me but not familiar with that particular sensor but even then it would not cause pinking. Are you sure its pinking ?? Regards Peter
Mondeo Pinking - Dan Terry
Yes it is definaetly pinking, it disappears when ign is retarded by removing the Octane Adjust Plug on the engine loom. Intake air sensor measured 25k ohms which according to specs I can find is OK. I will look into checking the timing but as far as I know its not adjustable.
Mondeo Pinking - Adam Going (Tune-Up)
Hi Dan,

According to my information (CAPS) the ATS spec is as follows.
20 degrees C. 37K ohms - 39K ohms
40 degrees C. 15K ohms - 17K ohms
60 degrees C. 7K ohms - 8K ohms
80 degrees C. 3K ohms - 4K ohms
Suggest you really need to check through temp range.

Suggest you also check compressions, although I suspect the chances of a carbon build-up are slight where the car is well exercised !

Regards, Adam
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