I have just started getting a vibration and shaking on my front floor pan driving at speeds over 90km/ph. It's not the pedals, it's under the floor pan.

I have rotated my wheels and had them balanced twice by Honda, but it's still there. The tires were also inspected and still perfect, the braking system also seems fine.

Any ideas as Honda don't?

 

Wheel alignment needed maybe? Hit any large potholes lately?

It could be a loose or broken belt in a tire.

 

Take it to a tire store, one considered to have the best service, and have them check it for true wheels, round tires, balance, and alignment. They should have a gauge they rest against the tire and wheel as they slowly turn it.

It's likely a bent wheel(s) or bad tire(s).

Feeling it in the floor pan would indicate the problem is on the back, but you say you rotated the tires and it does the same thing. Might be more than one tire/wheel.

I had a similar problem on another Honda. Honda sent me to the tire dealer that manufactured the tires (goodyear). Goodyear sent me back to Honda saying the wheels were not true (straight and round). Honda said the wheels were within factory specs. Finally goodyear replaced a couple tires and it improved, but it was never really good until I replaced all four tires with Michelins. Sorry, I know how aggravating vibration can be.

 

When you have vibration near that ~100km/ph speed then it's a balancing problem.

Is this stock wheels and tires? Are the rims hub-centric?

Try another dealer or a reputable tire shop.

Good luck.

 

check to see if you have a leaking strut. some times weak struts can cause what feels like wheels being out of balance.

but yes, as suggested above, i would get the tires rebalanced and checked for
wheel bends. if the store uses a hunter roadforce, they can detect that.

 

Actually, I have the same problem with both my 15" original wheels and 16" aftermarket wheels fitted.

I had to put my original wheels back on the car so Honda would even look at the problem.

Everyone including myself goes for wheels and tires. It seems impossible for 8 wheels and tires to be unbalanced.

There is no steering or brake shake, it's a vibration on the front floor pan only. I feel it most around the dead pedal area.

Struts and springs are OK for sure.

 

Imbalance with a drive axle of something similar?

Have you hit anything?

 

wheel alignment or maybe need hub centric rings to center your wheels properely.

 

Does the vibration occur while coasting? Have they checked the wheel bearings? My GE has a slightly toed in left rear and will make a very slight shallow diagonal wear pattern if I don't rotate frequently, I would take the car to a place that does road-force balance and have them checked.