AC Compressor

[plasma99]

Hi.  My Avensis engine started making a squealing noise which perfectly matched the engine revs.  There were some accompanying burning smells which entered the cabin.   I thought it was a slipping drive belt so ordered a new one.  However, a few days later the squealing stopped.  I thought that the problem had resolved itself until I discovered that the air con in no longer working.  I am now guessing that the AC compressor failed.  Reading previous posts, most people complain about a tractor like rattling noise coming from a failed compressor and bypass it with a shorter belt.  I have no such rattling noise and the belt is continuing to drive the compressor.  Can I continue as is or am I risking a further catastrophic failure?

The reason I ask is that I cannot see how the drive belt can be easily changed by a non-mechanic like myself.  There is no room to work and there barely seems enough space to remove the old belt never mind rerouting a new one.  I've no problem living without AC.

[Stivino]

You say the belt is driving the compressor but, the belt always turns the pulley, it doesn't drive the compressor until it is switched on.  Can you confirm that the compressor is kicking in when you switch it on?

[plasma99]

2 hours ago, Stivino said:

You say the belt is driving the compressor but, the belt always turns the pulley, it doesn't drive the compressor until it is switched on.  Can you confirm that the compressor is kicking in when you switch it on?

not at the moment.  No audible change in engine tone when you hit the A/C button.  It was definitely working before the squeal started.

[Stivino]

If it doesn't kick in, it might need some gas.

You can't really diagnose it properly unless everything is working as it should.

[furtula]

Could be just the compressor clutch is worn out, that would explain the squeal going worse over time, as it was maybe slipping.

But could also be problems with electrics, since the clutch uses electricity to engage and stay engaged to the pulley.

Did the burning smell, smelled like burnt clutch, or something else, maybe burnt insulation,plastic etc?

 

 

[plasma99]

Stivino, I don't really want to spend any money on re-gassing it the compressor has stopped working.  

But I think you have answered my original question - I can keep using it without bypassing the compressor because the current belt is just driving the compressor pulley?

P.S. Is it really difficult to change the drive belt or am I just being an idiot?

[plasma99]

8 minutes ago, furtula said:

Could be just the compressor clutch is worn out, that would explain the squeal going worse over time, as it was maybe slipping.

But could also be problems with electrics, since the clutch uses electricity to engage and stay engaged to the pulley.

Did the burning smell, smelled like burnt clutch, or something else, maybe burnt insulation,plastic etc?

 

 

can't really say.  It was just a general burning smell.  Can just the clutch be replaced - if it was that?

[furtula]

You might not want to fix it now, but summer comes, and you regret your decision imediatelly...

There are clutch kits, so you should be able to replace it,  and looks straight forward to do, but then again could be something else. 

I would check the pressure, if it's still gassed, and probably is, i would at least try to troubleshoot/fix it.

Try the link below, it must be opened using Internet Explorer / EDGE, i have none so i cant check if it's good, but should be a working manual.

http://manualespurdy.cisdigital.com/Toyota/AvensisAbr2006/contents/index21.html

[Stivino]

1 hour ago, plasma99 said:

Stivino, I don't really want to spend any money on re-gassing it the compressor has stopped working.  

But I think you have answered my original question - I can keep using it without bypassing the compressor because the current belt is just driving the compressor pulley?

P.S. Is it really difficult to change the drive belt or am I just being an idiot?

Correct, the belt is only spinning the compressor pulley, there is no load on it until you switch on the A/C.  It has an electric clutch. When you switch on the A/C you are only engaging the clutch but, the clutch won't engage if the system is low on gas.

I don't think the belt is particularly difficult to change (I've done it) nor do you need any special tools.

[paul9]

There's a diagnostic built in to the aircon system, I personally can't remember how to access it, but I think the codes can show you if the refrigerant gas pressure is too low to start, although I would be suspicious of that clutch, myself. If you are in the UK, then Kwik Fit and some others will fill your system and not charge if they can't  the aircon temperature down, subject to conditions. Also, they will not fill it if their machine detects a leak. I have used them as basically a free diagnostic in this case, but I was fully prepared (and hoping) to pay for a working AC system.

[plasma99]

Diagnostics - With ignition off, hold down the AUTO and RECIRCULATE buttons.  Then turn on the ignition.  Let go of the buttons and wait for a few seconds.

Mine settled on flashing "00" which I think means all is OK in terms of pressure.  I definitely suspect the compressor clutch now.

[plasma99]

Just a quick update to this.  The alternator failed shortly after my last post.  I think now that that was the original cause of the squealing and burning.   However, the air con is still not working - I don't know if the two failures are related or which of them happened first.

I got the alternator changed but unfortunately the car failed it's MOT for a catastrophic failure of a rear brake pipe.  I was quoted £300 to fix.  I was also advised that it needed a new Battery, new brake discs/pads all around and a fix to some sort of oil leak relating to the timing chain/drive belt cover?? - my brain had shut off by this stage.   I have decided that I cannot throw anymore money at the car.  The garage have offered to square the bill for the alternator change/MOT by taking the car on which I will probably agree to.

None of the above dampens my appreciation of the car.  It has provided me with eight years of reliable motoring and the car doesn't owe me any money.  Unfortunately, everything has suddenly gone at the end.