Spark Knocking or Exhaust Leak?

[70stangcoupe]

Getting sort of a rattling sound when I get on the gas, and I can only hear it with the windows up.

On the highway in 5th gear at 65 mph, If I floor it, I can hear a pinging sound, kind of like a marble in a metal container bouncing around. My mods are in my sig, so I figured I was spark knocking and needed to run a higher octane. I filled up with 93, and after 20 miles, it's still doing it.

Could it be spark knocking, or could my professionally installed BBK o/r X be leaking?

 

[70stangcoupe]

...Please?

 

[Roger_4.6_96]

Pinging Detonation. I had the same Problem and got rid of it with octane booster.

You might need

1. Octane Booster
2. Fix Your Timing
3. And if it only does it when its hot you probally need better cooling system.

 

[70stangcoupe]

How can I fix my timing? I obviously dont want to run octane booster with every tank.

Why will I need a better cooling system if it didn't ping when the car rolled off the factory floor?

Can I use a Steeda Timing Adjuster to move my timing back to 87 Octane?

 

[02LaserRed2V]

*bump*

I have the same problem also. And my "Service Engine Soon" light is now on. I think my ride has lost some "giddy-up" as well, because of that.

 

[Roger_4.6_96]

Probally something in the fuel system. get some octane booster and see if it burns it out of there.

 

[70stangcoupe]

Fuel system cleaner or octane booster?

 

[dbucfan]

check to see if the egr has come loose from the exhaust pipe

 

[BMan5150]

Getting sort of a rattling sound when I get on the gas, and I can only hear it with the windows up.

On the highway in 5th gear at 65 mph, If I floor it, I can hear a pinging sound, kind of like a marble in a metal container bouncing around. My mods are in my sig, so I figured I was spark knocking and needed to run a higher octane. I filled up with 93, and after 20 miles, it's still doing it.

Could it be spark knocking, or could my professionally installed BBK o/r X be leaking?

It's spark knock/ping/predetonation. Considering you've got a 1997 GT, I'm guesssing you also have a fair amount of mileage on your car. Regardless, get some electrical component cleaner, remove your MAF (carefully - and I think it takes Torx security bits) and clean your MAF. Bet that fixes your pinging/preignition problem - especially since you are already running 93 octane. Good luck and report back! This is a cheap fix too, by the way, even if you have to buy a few torx bits!

 

[StangDriver5650]

Good advice, I think that many people overlook the importance of keeping a clean MAF. I clean mine every 15k miles just to make sure.

 

[twogts4us]

Sounds like the addition of the O/R X caused you to go lean. You asked about "moving the timing back to 87 octane" - has your timing been adjusted? Do you have a chip or tune of any sort that bumped your timing? Did you just get the O/R X installed and then this started happening?