Problem with a 95 Protege

[DaiMonPaul]

Hey guys, I have a 95 Protege, automatic transmission, just over 120,000 miles. When the engine is warm, whenever I press down on the gas pedal hard enough, a "rattling" noise comes from the front. I've had multiple mechanics tell me that it's just engine ping, but the car has been doing it for a long time, plus no cleaners seem to work. The car still accelerates with that noise (at a slower rate than it probably should -- there's not really any hesitation, but it's slow), and it maintains its speed fine without any noise. It also usually doesn't make it when I only lightly depress the gas pedal, or when just starting up the car in the morning (but it WILL make it when I start up the car after driving it during the day, when the engine hasn't been sitting there cold overnight).

Any ideas on what could be wrong? Thanks in advance!

[Soy]

Not sure... you might want to post this is the normal Protege forum... this one is for MSPs.

[DaiMonPaul]

Not sure... you might want to post this is the normal Protege forum... this one is for MSPs.

Ah, my mistake... thanks.

[c7scayman]

Fill the tank up with premium gas then it should be fine after that.

The octane is messed up in the tank. The gas in the tank is dirty because the gas tank is dirty. Put a tank of premium and it should fix the problem for a while, but the problem will come back after maybe 2 months.

[xboxlivemonkey]

could be left over carbon stuck in the manifold .