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Vehicle:

2000 Ford Windstar, 3.8L V6 engine, automatic transmission, 166,000 km, recently purchased, was brought to me for some torubleshooting and minor repairs

Symptoms:

  • Occasional hesitation
  • Check Engine Light on, code was "cylinder 5 misfire"

Troubleshooting done so far:

  • disassembled wiper blade cowl and removed wiper assembly to gain access

  • removed spark plug cables (resistance test not done yet)

  • removed spark plugs: #5 looks new except for some brownish colour, the other 5 are pink, all gaps are on the high side (high 50's, should be mid-50's)

Pictures Cylinder #1 Cylinder #2 Cylinder #3 Cylinder #4 Cylinder #5 Cylinder #6

Question:

  • What causes pink colours on spark plugs?
tlhIngan
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1 Answers1

7

I assume you already checked the heat range.

The pink color has a similarity to the "ferrocen" symptom. Ferrocen is an iron-containing anti-knock fuel additive. It causes red, electrical conductive, deposits on the spark plugs. There are cases documented where is was illegally used to increase the octane rating of cheap fuel (google "Firepower ferrocene spark plugs"). According to Bosch (sorry for the German reference) cleaning is futile, you must replace the plugs (and the fuel station?).

Perhaps you want to ask the owner if he uses some fuel additive or prefers a certain brand of "special" fuel at a station where it is spectacularly cheap?

Edit: I also found an additional reference from champion (first picture on the top left)

Martin
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