Hi Folks. I am new to this forum and was wondering if anyone can give me some advice. My 98 Crown Victoria LX (non-police) pings.It has 91,000 miles.

I hear a pinging / metallic rattle on light to normal acceleration like at certain RPMs a little before each shift. I have had to switch to Exxon 89 gas to limit it. Regular 87 octane really makes it ping even worse. I have tried Chevron gas too. No no-name junk gas. I have run thru about 6 cans of B&G and Sea Foam cleaner and have changed the fuel filter.The air filter is clean and new also. I do have the original plugs from the factory as the book and even the service advisor don't advise on replacing them until 100k.

My service advisor said there is no way to check the timing and adjust it, it is preset and non-adjustable from the factory. He said I should try unhooking the battery for at least 10 min and letting the computer "reset" to re-learn my driving habits.

I bought it 2 years ago with 53K on it and drive it mostly highway and have put on about 39K. I drive it easy and get about 23 mpg (a pleasant surprise) with mostly highway driving.

Any advice?

 

All 4 of the crown vic/grand marquis that I've owned had this problem to some degree. Did you allow the seafoam to be sucked up through the pcv valve with the engine running (instructions on back of can) or just put it in the gas tank? If you already ran it through the pcv valve try it a few more times carbon build up seems to common in these cars. You may have to have it de-carboned by a reputable shop.

 

Have the hertz checked on the MAF sensor. The MAF hot wire will get dirty and cause the barometer to read wrong and therefore cause the PCM to alter the amount of fuel going to the engine. For reference, we are at approximately 1000 feet and our normal hertz reading is about 157.