Lexus RX 300 RPM go up when driving at 40 MPH

jump the switch if lights come on then you need a switch

Spin that wheel by hand as fast as you can. If you can hear the noise coming from right behind the tire it's probably a wheel bearing.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Do you have a tow hitch on your truck? Does it rattle when driving on bumpy roads? I had a truck same year and make when on a certain road the timing would ****** problem traced to knock sensor.

Over drive should be on (automatic) all the time. If you have it turned off , turn it on. It is for fuel economy. Over drive usually kicks in around 45 to 50 MPH. When you want to turn it off is if you are pulling something on hilly roads. And pulling something and you feel the overdrive kicking in and out even on flat roads

the trans may not be shifting into overdrive.

90000 is a suffficiently long time for a timing belt. I'd listen to the dealership.

If it is running perfectly I wouldn't think that you would need to replace the timing belt. You shouldn't need to replace that until 100,000-120,000 miles. I would definitely hold off until now unless you have start having some timing problems. Let me know if you have any other questions. Thanks for rating my response and for using FixYa!

$700

timing belt
idler pulley
water pump
timing belt tensioner
valve cam gasket
coolant flush
spark plug
oil change
pcv valve
tranny oil change
differential fluid cahnge
drive belt
upper/lower radiator hose
brake system flush
air filter

good luck,i hope this help pls dont forget to rate me thanks

shaking problems star.. from front end.. check you tires out of round shape.. balancing tiress. inner and outer tie rods. alignament

yes its related to knock sensor because car is running rich in fuel, and car runs of on safe mode, so overdrive will be off. have you and a friend replace it. remove intake assembly, then intake manifold, but first remove your anifreeze from radiator, trust me you want to remove antifreeze! their are brackets by the fire wall to hold down the manifold, thats the hard part is taking it off and putting that on since not to much space to work on it. on the block you'll see the two knock sensors, has 2 wires each, knock sensors cost between 150- 200 a piece, still cheaper than dealership putting it on. also buy some liquid gasket because you will need that. after putting it all back together reset the ecu and you should be fine,