Guys,

Anyone know what this could be? I have a 2005, Camry XLE V6 3.0. When I start the cold engine I hear a "whoop, whoop, whoop" sound which will last for about 30 seconds to a minute then is stops. I'm thinking it could be a belt but it is difficult for me to isolate where it is coming from. Any input on what may be causing this would be helpful. BTW, the car has about 79K miles on it, it is low milage for a 2005.

 

Could be a damaged drive belt.

Use a section of rubber hose as a stethoscope to narrow down the noise area.

Engage the A/C at start up to determine if the noise changes.

 

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Thank you. When you refer to Drive belt are do you mean the timing belt?

Thx,

RG

 

The engines does not have a timing belt but a timing chain.

The belt(s) on the outside of the engine and operate the accessories.

 

Joey, the 3.0 V6 eng does have a timing belt. Noise is definitely coming from the driver's side of the engine. It is weird. It is there at start up but then goes away after 30 to 60 seconds. The mechanic at my local shop is a former Toyota tech and he is not sure what it could be. He did turn on the AC and nothing happened. He thinks it could be the PCV. What do you think? Car runs great. Just 80K miles.

 

I stand corrected, thanks!

You state the noise is on the passengers side as is whoop, whoop. Could this noise be air generated as like a wind musical instrument generates sound? .

This engine may have something called an acoustic control induction system. This valve is on the intake manifold. By varying the valve opening the effective length of the intake air chamber is changed which is supposed to increase power. Perhaps the valve is moving around when is should be stationary or other issues which is causing the noise. .The valve is mechanically controlled via a vacuum diaphragm..

There may ALSO be a something called an air intake control system. This is a valve inside the engine air intake and BEFORE the intake manifold. This valve is supposed to reduce air intake noise at low engine RPM. This valve is located after the air cleaner box.

The air cleaner has two air connections to intake manifold. One connection goes through the valve to the intake while the other goes through a resonator box to the intake. As the valve closes more air goes through the resonator box changing the sound.. Perhaps this system is making the noise. This valve is also mechanically controlled via a vacuum diaphragm.

The valves being controlled by vacuum have electrically controlled solenoids valves that turn the control vacuum on/off.

Suggest you use the hose stethoscope to check noise on the intake manifold and after the air cleaner box. Both valves should be viable but may have covers.

For the PCV concern you can disconnect the hose from the valve and plug it and the valve air port for noise testing. . .

 

Thx Joey, but the noise is coming from the driver's side of the engine. I did change the PCV and cleaned out the MAF which is just after the air filter. It is not coming from the throttle body. Still hearing the noise. Seems like it is coming from the area below the air filter. Heard it again today. When I first start the cold engine there is no sound but when I put it into gear it will start about 3-5 seconds afterward. Like I said, it will last for about thirty seconds after I begin to drive. The guy at NAPA said nothing to worry about, just a cold engine. It's driving me nuts.

 

????

The noise is under the air cleaner box?

Does the noise change sound level or rhythm with engine RPM?

Have you listened to the transmission bell housing/torque converter area?

 

I only hear the noise when I start a cold engine. It becomes very pronounced when I shift into gear. It lasts for about 30-40 seconds then slowly fades away. Again, it sounds like it is on the driver's side of the engine under the air filter. Could it be the oil pump warming up? Its a 2005 with just under 81K miles on it. I may just have to take it to a toyota dealer. Local shop has no idea what it is. Other than that noise the engine runs just fine.