97 GT crackle (knocking like noise) from underneath


Active Member
Jul 9, 2003
Holly Springs, NC
I haven't been on this board in forever and man has it changed! Hopefully the same die hard helpful gear heads are around to help me with this one!

I am totally confused by this issue...

My '97 about 6 days ago presented with a very odd crackle/knock sound from what sounds like beneath the shifter. I 1st noticed it exiting the hw I down shifted and accelerated onto the offramp. Nothing aggressive, but I heard what sounded like plastic smacking underneath my shifter, or that sound when you drive over fresh asphalt of the pebbles hitting underneath. 1st to 2nd I heard it from around 2250 rpm -2500rpm. 2nd to 3rd I heard it at the same rpm range. Rarely I will hear it lower at around 1800-2K. It is always 1st to 2nd or 2nd to 3rd. I don't think I have heard it from 3rd to 4th at all. This is a bone stock '97, and I mean bone stock. I have ran 87 octane since I have had it (a little over a year.)

Honestly it sounded a lot like spark knock so on my last fill up, I put 13+ gallons of 93 octane. Nothing, it sounds exactly the same, so I am a bit confused as to what it could be.

Within 4 days of that noise a check engine light came on so I had the code(s) pulled. There were 2 codes but both were the same code of P1443 which is the EVAP canister (possibly EVAP Flow sensor.) The store only had the canister so I swapped that out and cleared the codes. This was done yesterday early am, and so far with about 60 miles on the car no check engine light has come back on but the rattle/knock/weird sound still exists. It may just be coincidence, but I wanted to put it out there since the timing was very close together.

Any thoughts on what this could be? It almost sounds rotational as well if that makes any sense.
  • Sponsors(?)