Lexus Es330 Behind Dashboard Vibration/noise

[ml30306]

Hello,

I own a 2004 Lexus ES330, mileage is about 120K. For over a year I have had a vibration noise come from behind the dashboard. The sound is like a light rattle. I have been to 2 Lexus mechanics who could not identify the problem. Both stated that the source was around behind the center dash near the firewall. Here the facts I know about the noise:

- Loudest when in Park when I start the car
- The sound goes away once the car passes ca. 900-1000 rpm.
- When in Drive at e.g. a light or fully stopped the noise is there once I pass 900 rpm, then it is gone
- When not moving and hearing the sound it will also go away once I turn the steering wheel in either direction, will then come again when I stop the steering motion
- Noise usually goes away after a while BUT when stopped on a hill driving slowly upwards the noise it very noticeable (maybe when kept exactly at the 900 rpm point)

Any thoughts on this?

[gbhrps]

ml30306,

I know of the es330, as my wife's last Lexus was the same year and model, hers with the navigation system.

That aside, the center surround that encircles the nav/radio/hvac systems just pops out as it is pried along its sides. Once off, it gives access to the screws/bolts that hold the 3 system components. Once the screws/bolts are removed each section can be pulled out enough to reach their backs and unclip their wiring harnesses, and then remove them.

That leaves you with a massive opening in the dash in which to explore and find your rattle. Remove the fuses (as a precaution) for each of the radio/nav/hvac and drive the car as before to track down the culprit. If there is no culprit, it most likely was one of the harnesses you removed, so when putting everything back into the dash, wrap each connector with some foam packing and tape. Hope this helps!

Search YouTube for radio/hvac replacements on similar cars (Camry's/ etc) to see what I mean by prying the surround off, etc. They're all pretty much the same. Good Luck!

[ml30306]

Hi,

thank you for your advice. Mine actually does not have the navigation system, so curious to find out what the technicians have not been able to.

[gbhrps]

ml30306,

Without the nav package yours will be even simpler to do. Don't worry about getting the correct connectors to match up, as they are all different, and the harnesses will only go back together one way. You can't get them mixed up, even if you tried.

Put the tranny in first gear, turn the car off, and pull the fuses I described in the last post. Then pry the plastic surround, and its pretty easy from there. Have a magnetic screwdriver or pickup tool handy, in case you drop a screw/bolt down into the opening.

Take your time and you'll do all right. Good Luck!

[ml30306]

Hi,

done, unfortunately no success. Taking the console plate, AC/Climate Control, and the radio out was no problem, maybe 2 minutes. Can't however isolate the noise. I also removed the glove compartment and cabin filter. One problem is that the warmer the engine gets the sounds starts to faint away. Thank nonetheless for your advice!

[gbhrps]

ml30306,

You may have partly solved your problem in your last post. It is possible that your noise is on the other side of the firewall, inside the engine compartment, or even under the cowl plastic covers that hide the wiper arm mechanism. Worth a look.

Tracing down noises and rattles always drives me crazy. About half of the time you think the noise comes from one area, only to discover that you were completely wrong. My 2nd OBW LTD (2004) had a rattle from the back end that drove me absolutely crazy! I looked underneath the car, nothing, took the entire cargo area panels from the car, nothing, and then rode in the cargo area as my wife drove the car. Bingo!!!

The rattle was the center shoulder belt that was stored in the ceiling by the tailgate. It wasn't properly locked down and rattled over bumps.

[ml30306]

Hi,

It is not driving me crazy but it indeed is annoying. I actually captured the sound, here the link:

You will see that at the end I stepped back on the gas and the noise immediately disappeared.

[gbhrps]

ml30306,

That sounds like the heater fan motor. Either something has gotten in to the squirrel fan and is rubbing up against the squirrel cage itself, or you have a bad fan bearing, or the vibrations its causing, is causing a wire or electrical connector (or similar) to vibrate in harmony with it.

Check out the YouTube vids on replacing the heater fan in a 2004 Camry (a close cousin of your car), which will be very similar. They are easy to change out, but yours may just need to be pulled and cleaned of debris. The worst part is working under the dash. It may be easier for you to pull the passenger seat out first. just to get some room for your body to work under there. Then again, you may be smaller than me. Good Luck!

[ml30306]

ISSUE SOLVED: The rattling came from the intake plenum. There are three hex bolts in the back, the one on the passenger side was missing, causing the plenum to vibrate against the metal bracket at certain speeds. 

Thank you for all the advice, much appreciated!