I recently noticed that there is a distinct grinding sound when I open the throttle up. It appears to come from the tranny tunnel area or under the passenger seat. The sound is not present when accelerating gently, coasting, or braking - only when I lay down a fair amount of throttle. This happens in every gear. Is this coming from the throttle cable? Or something else? If the former, has anyone done a R&R of the throttle cable? How involved would that job be?
Forgot to specify: 3.4 liter engine, 6MT.
I would look at your engine and transmission mounts. I bet the torque is flexing everything to point of having the engine or tranny contact something on the body.
Also, our cars do not have a throttle cable, it's drive-by-wire. They do have shift cables, though, which is a possible source of noise. I would still bet on the mounts.
Very helpful info. I’ll look at the mounts.
Quick follow-up question: I did change the stock shifter and cables for
Numeric
, but did not immediately notice the new noise. Any further thoughts based on that?
Get under it with strong light and look for physical evidence that correlates to the noise, it might be readily apparent.
You can feel the engine wind up if you hammer it in second gear then jump off the gas and then back on. My guess is your engine mount is shot. That would make sense that it happens under heavy load.
Next
question: if it is an engine mount issue, would it do any harm to do a track day before addressing it?
I wouldn’t take it to the track. For one thing, it’s not certain that it’s the engine mount. It could be something else.
But if it is the engine mount, you don’t want the engine essentially being loose in there as you go to full throttle multiple times a lap. It will also put extra stress on the transmission mounts and other items which are not designed to move as much as they will be moving with a damaged engine mount.
I’m not entirely convinced it’s the engine mount, why? That usually produces significant vibration in the steering wheel not a grinding noise.
Numeric cables
can pickup and carry transmission noise into the cabin. I noticed it immediately after installing but it has been so long ago that I have gotten used to it and I couldn't describe the sound. I also went back and updated the cable insulation, which made it more acceptable.
But I wouldn't characterize it as a grinding sound
Wouldn’t imagine that the cables are the source, unless their routing was incorrect or something shifted or loosened causing them to make contact with an engine component. Either way I wouldn’t venture on to the track with an uninvestigated and unconfirmed strange noise. I’d be afraid of making things worse at best, or something catastrophic and costly at the worst.
I will get the car in the air this weekend to have a good look.
