03 RX300 "Gurgling Noise"

Recently, a noise that I might best describe as a "gurgling noise" has been coming from the center console of my RX300. The noise is intermittent, however. When I had the RX serviced by my Toyota dealer, the noise was present and they diagnosed it as air in the cooling system or something like that. When they increased the temperature of the climate control system, at one point a "thunk" came from the center console and the noise went away. When the temperature was lowered, the noise returned. But the noise occurs whether or not the a/c compressor is one and even if the climate control system is "off" completely. The Toyota dealer bled the air from the system, but the noise has returned a couple of weeks since the service. Any ideas what might be the cause? The a/c heat are working fine, however, and the Toyota dealer has serviced and done maintenance on my RX on numerous occasions.

Reply to
J Golden
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Noises are difficult to diagnose without hearing and experiencing them first hand. If the noise sounds like sloshing from under the glove box, the drain tube for the evaporator housing may be disconnected or plugged.

Air in the cooling system can result when the cooling system is serviced or if there is a leak in the cooling system or if the radiator cap is bad. Check the coolant level in the coolant overflow tank. If it is below the "cold" mark when the engine is cold, add coolant, set the interior temp to full hot, and let the engine warm up fully. As the coolant level in the overflow tank drops, top it off.

Reply to
Ray O

The best comparison I could make to the noise would be a household timer; the kind you might plug an appliance or lamp into. The timer for my underground lawn sprinklers also makes a similar noise. The noise is NOT coming from the dash. It seems to be coming from the area between the drivers and front passenger's seat. That also is where the "thunk" noise occurs when the climate control temperature is raised to change the system from A/C to heat. The RX has two air outlets at the rear of the center console to direct cool air to rear seat passengers. I'm wondering if the gurgling noise has anything to do with airflow to those two outlets, since it seems to be coming from the area immediately in front of them.

Reply to
J Golden

I think that there is a motor/servo that moves the center vents back and forth. When you hear the noise, try turning the back and forth function off or put your finger on the tab on the vent and see if the noise disappears.

Is the sound present when the vehicle is sitting still or only when it is in motion?

Reply to
Ray O

Reply to
J Golden

Check the condition of the automatic transmission fluid. It should be translucent red in color.

Reply to
Ray O

Transmission fluid is fine. I was wrong however in saying that the noise comes from between the drivers and front passenger's seat. A friend said it definitely comes from the dash, near the passenger's side airbag. He described the noise as "water bubbling". When I turn the climate control system off, the noise, strangely enough continues. However, the one thing that is consistant is if I turn the temperature up, it gets to a point where I hear a small "thunk" like a door flap changing position or a door closing in the dash, and the noise goes away. So which vents are selected (top, bottom, both) doesn't matter, whether the a/c is on or not doesn't matter, whether it is on recirc or fresh air doesn't matter. What matters seems to be when the system is set to a high enough temperature.

Reply to
J Golden

Coolant bubbling through the heater core?

Reply to
Richard J Kinch

I was thinking that there might be air in the coolant. The thunk sound is probably the sound of one of the blend doors opening or closing.

Reply to
Ray O

The temp control causes all three hvac servo motors to actuate as needed. Try turning your car to the "acc" position so all the dash lights are on and then manipulating the temp control; that should remove coolant noises out of the equation as the engine is not running and so no coolant is circulating through the system. Or, better yet, take it to the Lexus dealer so someone can actually listen to and diagnose your car (instead of the Toyota dealer who apparently was just guessing).

******* Good idea, but the ignition key has to be on the "on" position without starting the car for the HVAC system to be energized.
Reply to
Ray O

oops, I meant to say "on" (with all the dash lights on)

********** I figured you meant to have the key in the "on" position, but I wasn't sure if the OP would know and miss your otherwise good advice.
Reply to
Ray O

with nearly 80,000 miles (135 kilo) driven, the warranty has long expired. It's due for its next service in late January. I'll have the dealer check it then, unless the noise drives me crazy and I decide to take it in earlier.

Thanks.

Reply to
J Golden

I had my Toyota dealer check the RX today. They searched for leaks (and didn't find any) and bled all the air from the system whatever air might have been in it. After four hours the noise remained. They now think that it might be water that might be leaking into the system rather than air. The attempted repair was done at no charge and they would like to continue to try to diagnose the problem and repair it. Apparently, no Highlander has ever experienced the problem that my Lexus RX is experiencing (the Highlander is very similar to the RX at least in the 03 year)

Reply to
J Golden

My Toyota dealer kept my Lexus for three days trying to diagnose and solve he problem. They checked the entire cooling system and found no leaks in the system. They checked everything and found no air or liquid leaking. The climate control system works fine! But, as they acknowledged, the noise remains. They suggested that I take my RX to Lexus if I can't live with the noise, but warned me that the cost of repair would likely be high (as if I didn't already know that).

I'm not enthusiastic about visiting Lexus again. In the NYC area that I live in, I've had experiences with several Lexus dealers and personally, my experience with their service departments was nowhere near as good as my experience with Infiiniti, Honda, and even my local Toyota dealer. The one exception (forgive me if it is wrong to name names) is Rallye Lexus in Glen Cove. They are an hour drive but the service that I have received in the past from them on my RX has been outstanding. Unfortunately, outstanding service comes at premium Price. But if I HAVE to take the RX to Lexus, I guess I'll take it to Rallye. I'l let everyone know how things go.

Bubsy

Reply to
J Golden

I took my RX into Lexus today. Naturally, today was the coldest day of the season (46 degrees f when I got there) so it was impossible for them to hear the noise. Nevertheless, they diagnosed it as the "AIX MIX SERVO MTR FAN" which they replaced for a bit over $750.00. Hopefully, they were right... time will tell if the weather gets warmer.

Reply to
J Golden

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