have a 2018 Discovery HSE 30,000 miles.

Scenario is when accelerating all is smooth and good until almost exactly 44-45 MPH, at this point (every time) a vibration and noise start. It is a low hum/buzz that sounds a lot like the tires were all of a sudden hitting the rumble strips on the side of the road although not really that loud or obvious. The hum seems to decrease significantly as soon as I am accelerating over 55 MPH.

I can feel the vibration through the body. I cannot feel anything through the steering. Any idea of what this issue might be or how I could systematically figure out how to approach resolving it?

Thanks in advance

 

Can you find a long downhill stretch of road. Accelrate to 40 (below the vibration speed), Put it in neutral so the engine goes to idle. And let the road bring the speed up to 44-45 MPH and then over 55 MPH and see if you can eliminate engine related vibration. Also you could try accelrating past 44-45 and past 55 with the paddle shifter holding you in 3rd or 4th gear to eliminate the cause being specific RPM. More info might help diagnose this. Another thing you could try is to swap tires front to rear and see if problem remains or if the vibration moves from seat of your pants (caused by rear tires) to the steering wheel (caused by front tires).

 

Any resolution?

 

Sounds like rear tire balance.

 

I've swapped all 4 wheels and tires with as new set no difference. I guess a balance will eliminate that. Cheapest starting point. God I hope you're right

 

Good luck. But if you're saying the vibration was there before and after the tire/wheel swap, tire balance probably isn't the answer. But, vibration not coming from the front (i.e. not in steering wheel) only at a set speed range is usually rear tire balance.

 

Looks like previous owner has fitted to brand new front drive shafts and prop shaft so maybe he gave up... Rear torsion bar d bushes are worn causing knocks but can't think it's connected.. Thanks for your replies much appreciated

 

Also putting in neutral doesn't effect so I'm thinking not gear box

 

Do you know if it's been in an accident previously and, if so, the severity and where the damage was?

 

No damage what so ever