Aircon noise

[Urban Womble]

I have an intermittent noise on a Yaris 2017 hybrid, that sometimes occurs when the air conditioning is turned on just after the car has been turned on (engine off). Mostly the noise is at a level you would expect, but sometimes it sounds loud like a very noisy pump. After a short while it will become quiet again. Turning the air-con off will stop the noise, and turning it back on will start it again. The noise sounds like it is coming from the driver’s side of the engine bay. Typically, it didn’t make the noise at the Toyota dealership as the car wasn’t cold, but I had recorded the noise and played it back to the Toyota engineer who confirmed it wasn’t right and changed the air-con pump under warranty.

Unfortunately the noise still occurs and is still intermittent. Does anyone know if either the engine coolant pump or the hybrid cooling pump turn on with the air conditioning? The engine coolant pump is right above the air-con pump and are known to fail, though the car has only done 34K miles.

I’m waiting for it to do it again and hope to get my listening rod onto the engine coolant pump and listen with my ear before the engine starts. You can’t hear it over the engine or inside the car.

Thanks.

[TonyHSD]

Hi, 

dealer technicians should be able to locate the noise and wether it’s a problem or a typical for the car model. Usually hybrids ac compressors gets noisier when the system is low on gas or it is very hot outside and the compressor needs to work harder to cool down the cabin. 
The water pump in question will be noisier on warm engine as when on cold it may not spin at all for some time after cold start depending on hvac settings. Do you have recordings of the noise to share you may get more ideas from others. But again, the dealer mechanics should know best as they have the car and equipment/ knowledge to check. 

[Derek.w]

Its maybe time for it tobe regassed is my guess as pressure is probably low.

[Urban Womble]

1 hour ago, TonyHSD said:

Hi, 

dealer technicians should be able to locate the noise and wether it’s a problem or a typical for the car model. Usually hybrids ac compressors gets noisier when the system is low on gas or it is very hot outside and the compressor needs to work harder to cool down the cabin. 
The water pump in question will be noisier on warm engine as when on cold it may not spin at all for some time after cold start depending on hvac settings. Do you have recordings of the noise to share you may get more ideas from others. But again, the dealer mechanics should know best as they have the car and equipment/ knowledge to check. 

Thanks useful insight. Interestingly we tend to hear it more during the winter months. It’s very intermittent and typically hasn’t done it when at the dealer. I’ll look at getting the recording uploaded.

 

 

[Urban Womble]

22 minutes ago, Derek.w said:

Its maybe time for it tobe regassed is my guess as pressure is probably low.

Thanks. They replaced the air-con pump so it would have needed a regas as part of that. The air-con itself works fine, nice and cold.

[Urban Womble]

This was recorded with me holding the iPhone outside of the car standing by the drivers side wheel. My daughter was turning the air-con on and off using the AC button. You can hear by the third test it is already starting to sound quieter. I haven’t been able to capture it again since the replacement pump was fitted.

 

 

 

 

[TonyHSD]

It’s sounds a bit odd although not unusual imo.
The first time was exactly how a Toyota hybrid electric ac compressor works, the noise is typical, the rpm changes are typical, nothing really concerning, except it sounds a bit louder, which can be low gas and oil. , or just from the recordings. I wonder if technicians just did the work became was under warranty which some really like, others avoid , don’t know but the ac behaviour recordings are exactly how these compressors work. 
The reason why every next time the compressor is quieter is because it spins  at lower rpm as no need so much pressure and so much cold gas. Longer the ac is on and working quieter it becomes. 👍

[Urban Womble]

Thanks for the reassurance. At the very least it means if there is something wrong we will just lose the AC vs. engine cooling. It’s my daughter’s car so I obviously want it to be reliable.

It’s going in tomorrow to have the wiper stalk changed on the steering wheel as rotating it to the jet and wipe position only triggers the jet and not the wipe afterwards. They tried changing the motor wiper first but it didn’t fix it. Interestingly the non hybrid models only have a jet in that position anyway. Last May it had a wheel bearing changed so whilst it hasn’t proved as reliable as I had hoped at least the warranty being extended via servicing has paid off.