As the title says, I've noticed a dull "thunk" probably half the times I press on the gas pedal. This also happens at the about the same frequency when I release it, while decelerating. I can only describe it as a feeling more than an actual sound, as if it were catching a gear, and only happens while I am driving.

Otherwise, it runs fantastically smooth, so I'm hoping that this is not too big of an issue. I'm also seeing my local JLR for an unrelated service (new brake pads) in a couple of weeks and I plan on bringing it up to the mechanic then. For reference, my F-Type R has 23300 miles on the odometer.

Cheers!

 

Any clue as where you think the thunk is coming from? We could do with more information!

 

My apologies, I should have specified! It feels like it's coming from the front/engine.

 

I can also feel the "thunk" at my feet.

 

I assume you only feel/hear this with the engine running. If true, I suspect that something, probably part of the exhaust, is contacting the chassis as the engine rotates due to torque, producing the "thump." I suggest getting under the car and looking for contact witness marks.

 

Motor mount?

 

Yes, could be that as well. I had that problem myself after I bought my car, though in my case, there was no thump, only suspicious marks on both the engine cover and hood... sure enough, bad left side mount.

 

Only occurs while driving—most notably in the lower gears. When idle, I don't hear/feel a thing, even when revving (aside from the normal snap-crackle-pop).

 

Upon further digging, that seems like it could be a possibility. Is there a surefire way to know for sure before I head to the mechanic?

 

Open the hood, start the engine, hold the brakes on, put it in Drive, and apply the gas slightly (to apply torque to the engine). If there's a failed left side mount, the engine will rise up. Not sure how to test the right-side mount.

 

same procedure you just said for the left mount but put the car in reverse

 

I actually said that but erased it because the engine is turning the same direction... thinking about it again though, I think you're correct.