I have a '99 SVT with 45K miles, running well.
This summer under hard acceleration with windows down I can hear a rattling sound from up front. The rattle reminds me of pre-ignition, except it seems to be coming from below. The heat shield on the cat is not loose, and I can't duplicate the sound by shaking or banging on the exhaust system. No other loose parts underneath the car. The sound happens whether or not the A/C is on. My butt-dyno detects no deterioration in engine performance and the clutch isn't slipping. I use 92 octane fuel. My guesses:
- Pieces of pre-cat rattling in the exhaust
- a clutch-related sound (I know what the low-speed clutch rattle sounds like).
- Some part of the SVT front valance, though I've recontented the two lower braces from the 98's.
- Pre-ignition and I just am not used to the sound in a newer car.
Search under keywords rattle, high, rpms, WOT, acceleration, came up with zip.
Any ideas?
Thanks in advance!
