Greetings All
I have noticed lately in my 2001 RX300 AWD a ticking noise coming from the engine. Here are the specifics:

1. Only ticks from appx 1800-2300 rpm.
2. Does not matter what gear it is in.
3. Does NOT tick in Park or with brake pedal held/no motion @ 1800-2300 rpm.
4. Does not matter if A/C is running or not.
5. No codes.
6. Minimal if any, loss of power
7. No loss in gas mileage.
8. Kids swear sound is coming from right rear of vehicle. (Exhaust?)

Before I start tearing into the engine, checking valve clearances, etc, just wanted to see if anyone else has seen this problem.

Thanks
Todd

 

Here is some more info in trying to solve this.
First, the noise is right around the 2500 rpm area.
It only is present during acceleration. The harder the acceleration, the louder the noise.
I took the belt off the alternator/air conditioner and ran it that way. Still same sound.
I can only hear it with the windows UP. If I roll them down, the sound is drowned out by the oncoming air.
(Could this be a cabin noise/fuel pump issue?)
Recently replaced rear bank O2 sensor but still no codes.

Any help would be appreciated

 

Couple of things:

Use your kids sharp hearing to help you narrow down the source.
Mechanic's stethoscope or screwdriver to the ear may help.
Dont go hell bent in finding the source of noise ... exception would be something that gets worse as time goes bye. Exploration in a old engine can be very expensive as things become brittle over time.

I assume the ticking happens when the vehicle is in Park [that eliminates tires, wheels and shafts]
Also look under the hood in dark .. to see if any arcing is going on.
Metal expansion and cooling also produces ticking sound.
Most notorious is the ticking due to injector.
Also look for electric motor ... like blower motor with piece of filter touching it.

Salim

 

Unfortunately the noise does NOT happen in park. Only while accelerating through 2500 rpm. Not even loading up the engine while in Drive with the brake on @ 2500 rpm will duplicate the noise. So that rules out the stethoscope and Dark troubleshooting.
I guess I could tape the kids to the side of the car and re-test��

 

Are you sure it is the engine?

Salim

 

Check the heat shields on the exhaust. Sounds like a resonance issue.