After I installed my Warpspeed Y-pipe I noticed a "rolling vibration" when engine was under a load.

Symptoms:
1. At a complete stop, car would vibrate excessively when
A. In "D" Drive.
B. In Reverse with brake applied.
C. Any Lower gear.

Process:

1. Cleaned Throttle Body
2. Replaced Gasket between Dual Duct Pipe and Throttle body.

Result:
1. Greatly Reduced "Rolling Vibration"
2. Some vibration, but seems to be normal operation of Pipe considering the stock has insulation.

Note: I noticed a clunking noise when jumping on the gas from a stop. Any clue on what this may be? It started when I installed my Y-pipe. My guess is either the Y-pipe increased my HP so much that it caused my engine to tear an engine mount (doubt it). My other guess is that the Y-pipe is hitting against front sway bar. The noise seems to be coming from that general area.

Open for suggestions.

Thanks in advance.

Maxipriest

 

Bingo

 

i had a similar problem
found my alternator bolt had broken and it would only show itself
in reverse or drive with foot on brake.
also at the same time my radiator bolts that hold the fan on had all
backed out ??!! tightened those,removed-drilled out and replaced the
alternator bolt and now all is good !