19mick87

2010 Avensis 2.0 D4d aircon bypass

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Hi I dont know if this has been brought up before, but basically my aircon compressor is making noise at idle and when driving it gets quite loud. No gas in system as the condensor has a leak, so Im guessing bearings are bad from running dry.

Is it possible to remove the aircon unit and bypass that pulley by using a shorter drive belt?

If so does anybody know what size belt is required. The engine code is 1AF

Cheers

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1 hour ago, 19mick87 said:

Hi I dont know if this has been brought up before, but basically my aircon compressor is making noise at idle and when driving it gets quite loud. No gas in system as the condensor has a leak, so Im guessing bearings are bad from running dry.

Is it possible to remove the aircon unit and bypass that pulley by using a shorter drive belt?

If so does anybody know what size belt is required. The engine code is 1AF

Cheers

Sorry its 1adftv engine

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Part number 90916-W2034 from your local Toyota dealer fits the 2.0 1AD without AC

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15 minutes ago, Devon Aygo said:

Part number 90916-W2034 from your local Toyota dealer fits the 2.0 1AD without AC

Cheers is there a diagram of the pulleys with the smaller belt on so I know how to bypass it?

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On 11/4/2018 at 3:53 PM, 19mick87 said:

Cheers is there a diagram of the pulleys with the smaller belt on so I know how to bypass it?

Hope this helps -

 AVENSIS |  V BELT

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The A/C compressor itself will not be running if there is no gas in the system because the low pressure switch will prevent this by keeping the A/C clutch deactivated. The clutch on the compressor will spin and it is possible this is noisy in its own right... but make sure as it may be something else such as a noisy tensioner or alternator bearing.

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28 minutes ago, Mooly said:

The A/C compressor itself will not be running if there is no gas in the system because the low pressure switch will prevent this by keeping the A/C clutch deactivated. The clutch on the compressor will spin and it is possible this is noisy in its own right... but make sure as it may be something else such as a noisy tensioner or alternator bearing.

Alternator is a year old so should be fine. Narrowed it down to water pump or  ac compressor. Have a leak in ac condenser over a year so no gas in the system had it tested in the summer so Im asssuming its the clutch in the compressor thats making the noise.

Got the shorter belt just havent had the chance to do it yet. Looks like the car has to be jacked up to get to the tensioner aswell.

When the belt is off ill check all pulleys and run the engine to see if noise is gone.

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Sounds like a plan... good luck and let us know how it all works out.

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17 hours ago, Mooly said:

The A/C compressor itself will not be running if there is no gas in the system because the low pressure switch will prevent this by keeping the A/C clutch deactivated. The clutch on the compressor will spin and it is possible this is noisy in its own right... but make sure as it may be something else such as a noisy tensioner or alternator bearing.

On many recent aircon systems there is no clutch on the compressor. Instead the compressor shaft spins all the time the engine is running with the aircon load being controlled by a swash plate inside the compressor itself. On both our 2009 Auris and 2012 Avensis the aircon compressors don't have a clutch. 

Having said that, this type of compressor is designed to be run for some time with no refrigerant in the system without sustaining any damage. 

You can usually identify this later type of setup by the fact that turning the aircon on or off doesn't produce the characteristic 'click' of the clutch from under the bonnet which older aircon systems used to have. 

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Are you certain ? I couldn't find reference to any type of non-clutch set up for automotive use.

A clutch under control of the pressure switches is one of the main safeguards in a system. You wouldn't hear the clutch cycle on and off as in a fixed displacement compressor as it would be engaged all the time the AC was on (unless overridden by external factors or the user switching AC off). 

 

 

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Just after swapping the belts around a pig of a job even with the car on the ramp. Very little space to work with but new belt fits perfectly.

The noise is gone and there was a lot of play on the aircon pulley which was also leaking a lot of the dye used when I got a leak test done on the system in the summer.

Thanks for the asvice and correct belt size its after saving me a lot of money not having to get a new ac compressor.

 

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Pleased to hear you have found a fix and its quiet now.

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On 11/8/2018 at 3:07 PM, Mooly said:

Are you certain ? I couldn't find reference to any type of non-clutch set up for automotive use.

A clutch under control of the pressure switches is one of the main safeguards in a system. You wouldn't hear the clutch cycle on and off as in a fixed displacement compressor as it would be engaged all the time the AC was on (unless overridden by external factors or the user switching AC off). 

 

 

Yes, they have become quite common in the past decade or so. VW for example have been using clutchless variable displacement AC compressors since the early 2000s, my 2007 Skoda Octavia had one. From what I can see our Auris and Avensis have this type of compressor too. 

 

 

 

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Interesting, thanks 🙂

An Audi I once had used a variable displacement compressor but it still had a clutch as a means of turning the system on/off and preventing operation in to cold conditions.

Your video seems to imply that compressor failure on the type of compressor shown would be handled by means of a friction plate designed to slip and fail should the need arise. Very interesting.

 

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The early clutchless compressors fitted to VWs unfortunately had quite a reputation for failing, and if they seized internally the pulley would freewheel to avoid the belt burning or being thrown off the pulleys. I used to frequent the Skoda forum when I had my Octavia and aircon failure on those (and the equivalent model Golf and Audi A3) was a commonly mentioned issue. Luckily I never had that particular problem on my Skoda. 

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I had the evaporator fail on the A4 (leak) but at 6 yrs old I didn't get it fixed (£500+ for parts plus anything up to 15 to 20 hours labour). It was one of many many issues with Audi. 

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My T27 2,0 D4D had same problem... Terrible rattling noise when idling. When I pushed the pedal a little bit, no noise.

First I thought that the timing chain has gone bad, but then I listened carefully with rubber hose and noticed that the noise is coming from a/c compressor pulley.

When rotating the pulley by hand it came out that there were too much clearance between pulley and that metal plate which is bolted to compressor shaft.  

Inside the pulley are some rubber dampers and they must have gone bad...

I searched this forum for help and found this topic. I watched  the video above and had an idea!

I extruded some elastic sealant inside the pulley through the metal plate holes (12) and after 24 hrs drying no clearance, no noise.

This is temporarily repair, but interesting to see how long it lasts...

Hope this will help others with pulley problems...

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