1998 Mercury Grand Marquis
>
> Engine pings on hot days with air on, going up hills in low gear - as I
> understand it, a somewhat common problem.
>
> I have cleaned the MAF per the instructions at
>formatting linkIt helped somewhat, but> pinging still bad on highway (around 70-80 mph) with air on.>
> Currrently running 93 octane which almost completely removes pinging,
> even in situations that really tax the engine.
>
> If anyone could answer the following questions or point me in the
> direction of a good FAQ, I'd greatly appreciate it. BTW, I'm on a tight > budget.
>
> I've read that the other cause of pinging is carbon buildup in the
> engine. Is this correct? What are the possible solutions? Is there an
> additive to the fuel that can correct this, or at least help it? If a
> mechanic is needed, what is it exactly that needs to be done?
>
> Thanks!
> -- Joel
>
I have heard the same thing about carbon build up. Might run some Sea Foam through it to clean out the carbon. I find it at the auto parts stores for less that $6.00 a can. A lot of us motorcycle riders use it with good results. Just a can put it in the tank and use the octane the car calls for.It might take a couple of cans/tanks to clear it out. Or it could be a knock sensor, if the car has one which adjusts the timing when it senses the pre detonation. Another good one recommended by a Volkswagen mechanic it a product made by Chevron called Techroline (sp?). It might be easier to find. Good luck!