Was cruising at highway speed in 5th gear. I then started to hear a rumbling noise that sounded alot like a flat tire. However there was no vibration. Pulled over tires were fine, started driving again. The noise then picked up again, and it sounded like it was coming from right under me. If I gave it gas the noise grew louder and faster, and I let off the gas, the noise slowed down. The car was still driveable, acceleration was in no way affected. It did this for a minute or two and then dissappeared. Maybe 30 minutes later it would start again, and then go away. Was driving in heavy rain but I can't figure how that would affect anything.
What's odd is when I pushed in the clutch and revved the engine, the noise grew loud but then vanished all together. Only made this noise within 4th and 5th gear at 50 - 60+.
Is it possible my clutch is going bad? I've launced once or twice getting that nice skunky smell.
The car hasn't done it since and I've driven for a while now, I just hope it isn't a transmission issue.