Car Air Conditioner Noise - 2005 Toyota Echo


I am just after some quick advice from someone who knows more about cars than me.

My 2005 Toyota Echo recently started making an almost grinding noise when the air conditioning is switched on. This didn't sound that bad from inside the car, but is quite loud externally. The sound appears to be coming from the left side of the engine bay but I was having a difficult time identifying exactly where.

I've recorded a short video of the sound when the air conditioning is on and off.

Due to the cooler temperature, I can't really tell if the aircon is working or not, but from what I can feel the air coming from the vents isn't noticeably colder with the ac switched on vs being just fan. Also, this sound doesn't occur when just the heater is on.

The sound doesn't appear to go away even when leaving on, and does seem to increase in loudness when the car is at higher revs.

From what I can gather, the likelihood is that the aircon compressor is going or is gone already. I haven't gotten any formal quotes but this seems like it would be expensive to replace, and given the age of the car I am not sure I would want to spend that much on it.

I might take the car to a service yard on the weekend to see if they can diagnose, but any advice is appreciated.


  • -1 vote

    spray WD40 on the serpentine belts in engine bay - prolly a bad idea if it slips

    so best to just change a new belt $100-200


      I am pretty sure I got new belts around a year ago as I was getting some squealing. I'd hope it isn't the belts as they are still pretty new at this point. The sound I am hearing does sound different also.

  • +2 votes

    Belts don't grind. They squeal.

    NEVER use WD40 on belts EVER. You can spray a stream, not a spray of water to one belt at a time. If it quietens down but I doubt it's the belts.

    You can purchase proper belt spray from any automotive parts store.


      I don't think it was the belts either. The sound doesn't sound like a squeal, it is more like a grind (which isn't a great thing). It would be great it if was the belts though as that would probably be a lot cheaper.

  • -1 vote

    That noise sounds quite loud. Try and see if the noise is coming from the fans at the front around the radiator as the fans usually start when you turn on the A/C. If it is where the noise is coming from, it's probably the A/C condenser fan that needs replacing


      If the radiator is what I think it is, it didn't sound like it was coming from that area (which would be more like the front centre of the car). Thanks though, i'll try having a closer inspection and listen once I get home.


    Could be AC compressor. Try wreckers


      I did see a 'used' working compressor on ebay for $99, but I assume labour to replace would be a decent amount.

  • +1 vote

    Don't run the air conditioner. It's likely to be the compressor wearing out. The more you run it the more metal shavings it's likely to deposit in your system. Replacing a compressor alone can cost around $600 (new), but if the system is contaminated with metal shavings then the repair cost balloons out to near $2k.

    Do not run the system. Get it repaired.


    If it is coming from the compressor then it could be the clutch slipping, or an internal failure, however you mention it doesn't seem to be cooling the air. In the past I have seen compressors make horrific noises when they're low on gas which just needs a regas/leak fix. But really there's no way to tell unless you go to a proper auto lecky/AC specialist unfortunately.


    You could test the AC by running the heater for a while, then turning the temp back down with the AC switched on and see if it feels cool, another test would be to see how quickly the AC air clear fog off the windscreen on cold. Might be fun fogging it up first too.

    The sound in the video sounds quite similar to the sound my alternator was making when a bearing went. Could be a bearing in something that is run by the belt, ie alternator, AC compressor, water pump and it makes noise only when additional load is put on the air cond. unfortunately a video doesn’t help me hear where the noise is coming from. You need a mechanic to have a look.


    my partners Mazda 3 had an AC failure.
    It started when we were on our way home from Jindabyne to Canberra, the AC started to vary in its operation, i.e. the cold air was changing temp and then essentially stopped being cool, we thought we could also here a slight noise change, so we turned it off and we tried it a few times, but no cold air and the noise gradually became worse, as the belt was not used for anything else we cut the AC belt off.

    we had it assessed and to fix it they quoted 3k as they were thinking they would have to replace all the lines as well due to whatever gave way may have put metal shavings into the lines which would just destroy any new compressor and there is no inlet filter.

    Needless to say we didn't get it fixed, but retrospectively we probably should have. We kept it for a further 4 years as it was a great little car, we recently changed it over, but we got bugger all for it due to the AC.


    Your AC compressor front bearing/clutch has failed or the internals pump section has failed. Needs a new compressor. It isn’t a DIY job, as you will need to de-gas the system to remove the compressor.

    Buy the part yourself, because most mechanics I know will add “naive” tax onto anything AC related. Don’t buy it from Toyota, they will add the same tax. The compressor will have a maker (ie: Denso/Bosch/etc) and part numbers on it. Use that to find what you need and take it somewhere to have it fitted.

    Obviously don’t run the AC, because if it has failed internally, you don’t want it filling the rest of the AC system with metal shavings and wrecking the new pump.

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