Driving a 2008 Lexus RX 350. With my foot on the gas pedal giving it a normal pressure and doing say a steady 25 to 35 mph I get a vibration that sounds very much like going over grooved asphalt. Let my foot off the pedal the vibration stops... immediately give it steady gas again and it's fine. Later on it will do it again down the road. My mechanic is stumped.
@chucktobias Not sure... What do you suggest? I'm not a mechanic... gut feeling is that it's some kind of gas feed problem being that it immediately stops when my foot is eased off the pedal... put back on the pedal it's fine for a while then a while later it does it again.
Can you feel where the vibration coming from? The accelerator pedal? The steering wheel? Your seat?
Did the mechanic check your brakes? Wheel bearings? Axles?
If he got stumped then you may want to take someplace else.
@imperator Will have to get it back in for more elaborate tests. Thanks Joe!
Another possibility is your transmission torque converter. Your description of feeling like driving over grooved asphalt is consistent with how many people describe the vibration from a torque converter beginning to fail. Good luck.
Not sure... What do you suggest?
There are many things that can cause vibration, and you're dealing with a 17-year-old car. (You did not mention mileage.) Talk to your mechanic and ask what specific diagnostic procedures were performed so we can possibly rule out what has already been covered. (If your mechanic is stumped that implies that a thorough analysis of the problem has been performed and no answer found.)
I'm not a mechanic...
Neither am I or most of us here, but many of us are experienced at working on our own cars.
gut feeling is that it's some kind of gas feed problem being that it immediately stops when my foot is eased off the pedal...
That should show up in live data. Did your mechanic at least perform a full diagnostic scan for codes and capture/analyze data? That's generally the first step if the engine is suspected, as well as checking basics such as filters, spark plugs, and fuel pressure. Also cleaning the MAF sensor and throttle body can sometimes be of benefit, especially on an older vehicle.
Of course if the vibration is being caused by worn-out suspension components there would not be any codes or data for that, visual inspection for worn components would be required.
Thanks For Your Help.