'02 Toyota Sienna wobbles when engine under load

and is more noticeable at certain speeds (like around 40 mph). The wobble is lateral in the body of the car and the steering wheel IS NOT vibrating.
AutoMD web site suggests it may be the motor mounts. I did their diagnostic suggestion of putting the car in gear with the emergency brake on and foot on brake … and revving the engine and letting up. I didn’t notice a “knock” when the torque was released on the engine.

My local mechanic is stymied … says he checked the motor mounts, and front end mechanics and they are OK …

Any suggestions???

THANKS!!

Try rotating the rear tires to the front. If this starts your steering wheel shaking, you know it tire balance.

Has anyone checked for a bent wheel?

I agree with chaissos. Switching the wheels front-to-back might provide some insight.

I agree with Chaissos and McP, but would like to add that it’d be a good idea to check the rear “mechanicals” too and to get a good 4-wheel alignment.

It’d also be prudent to assess the condition of the engine with a compression check and a check of the vital signs (ignition system look-see on the analyzer, see how the plugs look, etc.). An uneven engine operation could easily manifest itself as a shake without migrating through the steering wheel.

Add the injector operation to my earlier comment. Injectors can be bench tested.

I think you may very well have a bad inner CV joint. Though all the other suggestions are also possible.