Rx 400h 2008 vibration under good

[Julie J]

I am getting an intermittent vibration under the hood.  Dealer can't replicate.  When it happens, whole radiator vibrates & makes whirring noise.  Any ideas on cause?

[HaloRomeo27]

Check engine mounts and front wheel bearings

[RX400h]

Quote

The intermittent vibration under the hood of your 2008 Lexus RX400h could be due to several reasons:

1. Engine Bay Fan: The vibration and noise could occur when an engine bay fan turns on. It’s possible that the issue is intermittent and doesn’t happen every time the fan is on.

2. Faulty Fan Mount: A busted fan mount could also cause such vibrations. You can test this by turning on the AC, which activates the fans, and see if that causes the vibration.

3. Engine Mounts and Wheel Bearings: Check the engine mounts and front wheel bearings as they could also cause vibrations².

4. Worn Out or Faulty Sparkplugs: In many vehicles, a common cause of engine vibration is worn out or faulty sparkplugs. Worn out or dirty sparkplugs will cause the engine to misfire or not properly fire on each and every cylinder.

5. Tires or Alignment: If the vibration occurs during normal driving whether you’re accelerating or coasting, it could be caused by the tires or the alignment.

6. Brake Pads: The vibration could come from the brake pads applying pressure unevenly across the brake rotor surface.

Since the issue is intermittent, the dealership should keep your vehicle, overnight if necessary, and run it when it is cold and fully warmed up. This is a common procedure when an issue is intermittent.