Hello,

I am new to this forums. I just bought a 2002 Lexus IS300 Automatic a month ago. I notice my RPM is quite high at certain speed.

At 65mph my RPM is 2600-2900
At 70mph - 80mph its at above 3000 RPM.

Is this normal?

I also have one more problem, When I brake at high speed, let say im going 70mph, my steering wheel would shake while I'm braking. What's the source of the problem?

Please help me out!

 

rpm's look normal.

 

First, welcome to the forums.
the rpms seem right on
The shudder seems to be warped rotors which is an easy fix.

 

Thanks,
I used to drive a honda accord 4cyc. The rpm is a huge difference. Wasn't really used to it. Since everyone say its normal, I guess I could rest assure.

And about the rotors, if its left untreated, is it dangerous to drive?

 

It is not really dangerous but it will cause the pads to wear out faster. This is a really easy fix. You should be able to do this yourself with basic hand tools.

Here is a DIY from my.is

http://my.is/forums/f89/brake-pad-ro...tached-255699/

 

this is how these cars intend to be a gas guzzler, its from the high RPMS ride..

 

yeah i came from a honda prelude 5spd and when i first drove mine i thought the same thing but its just how these things run

 

yup rpm looks fine. Change ur rotors and pads. just 2x 17's and 1x 14' u need to take out after the wheel. Did mines yesterday and it took about 20-30 minutes.

 

I finally Change the rotors and pad. Now there is no vibration slowing at 60-70mph. Thanks guys!

When I removed it, It turn out the previous owner have aftermarket pads one side, and OEM on the other. One side is not even and it has less than 1/4 life on the pads. Thank god I check on those. And the aftermarket, it has a lot of life but its uneven. Both rotors are pretty banged up.

love my is!

 

Your Lexus IS300 should be at 2200-2300 RPM's at 70 mph. Your car isn't shifting into 5th (OD) gear. You can make the adjustment by adjusting the cable on the throttle body. What usually happens, is the throttle body is removed to replace the spark plugs and when the throttle body is reinstalled they tighten the cable (nut) on the wrong side, being there is two nuts, one on each side of the cable bracket. Note: The right way to adjust it: have someone push gas pedal to the floor (with the car off) check to see if the cable is opening the lever all the way, if not or if it 's bottoming out make necessary adjustments and tighten nuts and when you release the gas pedal your cable should be set in the correct position. Basically the leaver should be all the way opened when the gas peddle is all the way to the floor.

 

51auto, unfortunately, your numbers are flawed.

Auto IS300's are a650e transmissions.

4th gear is a 1:1 ratio, 5th gear is .753:1

Rear diff ratio is .392

With a 215/45-17 Tire (OEM), 24.6" diameter, Vehicle speed at 3000 rpm in 4th gear would be 56 mph, and 5th gear would be 74 mph. At the 2200 rpm you quoted, you would only be going 41 in 4th and 55 mph in 5th...

 

Ya all auto IS300's run high rpms. I remember having a '94 Tbird with the new 4.6. At 70 I think it was at like 1900 Rpm and also got 29 mpg on freeway driving between 60-80 for 200 miles before reformulated gas. Ahh the good ole days.

 

Did you figure this out

 

It was answered.

All auto IS300s run higher RPM on the highway. That's just normal for these cars.

The shudder while braking is either warped rotors or wheel bearings. If you put new rotors on and the car is still shuddering, it's 100% wheel bearings at that point