My fox is pinging hardcore

[Un©ommon]

Took the stang' out for a drive today and ended up getting stuck in traffic downtown. Stop and go and red traffic signals everywhere you look. After I got out of that mess I was cruising down harbor drive outside base and I heard this sound, similar to a bubbling deep fat fryer. I didn't think it was knocking at first because it only did it when I let off the gas and there was load on the engine, i.e. down shifting and letting it wind-down, but then I heard it at the top of third gear around 4k RPM. It was inconsistent but very loud. I did a U turn and went and parked so I wouldn't damage anything.

I have never heard knocking this loud before, if that's what it really is. Any input on this situation? The car was a little hot because of the traffic so I figure that plus my blower might be causing it.

Any input at all is appreciated!

 

[wickedstangs]

Sound like its out of timing..

 

[GLDNPNY]

Your stint in traffic made the engine hotter than it usually is and when that happens it is easier to develop pre-ignition, otherwise known as detonation. This is where there is a combustion event without a spark plug firing. The residual temp in the cylinder from the prolonged stop and go actually ignites fuel/air mixture at times other than when the plug fires. My advice would be to recheck base and total timing and either pull a few degrees or invest in a water/methanol injection system. Both will reduce the chances of detonation however pulling timing will cost you a few ponies. Also make sure the fan is working properly. If you still have a mech fan (cant remember what you have) ensure the clutch is still good. If it is an electric fan make sure you are getting a good 12 volts to it even at idle. If your charging system isn't up to snuff the fan won't turn as hard since it has fewer amps than are needed and won't cool in traffic. Also, do you have a good aftermarket temp gauge? Stock Fox gauges lose their accuracy after 20 years or so.

E

 

[Un©ommon]

I actually just bought a meth kit last week, just waiting for it to get here. I have a mechanical fan but I plan on upgrading soon and I guess I will have to buy some gauges finally... I'm going to check the timing today probably and run it around since its nice and cool out.