1993 (Kouki) Gt-R - Tapping/ticking Noise When Aircon Is On?

[mjtown]

Hi all,

Pop quiz – what do you think is causing a tapping/ticking noise when my aircon is turned on?

1. It only occurs when the compressor is engaged, and goes away when the aircon is switched off;
   
2. It doesn’t occur when only the climate control fan is on;
   
3. It is worse at low revs – particularly at idle
   
4. The ‘rate’ of tapping/ticking increases as revs increase but the volume of the noise diminishes as the revs increase (and this is not just because there is more ambient noise);
   
5. My aircon works fine, even when the noise is occurring.
   

The car is a 1993 R32 GT-R. I recently had leaks rectified and the system was regassed with R134a after several years of relative inactivity - i.e. it was sat in a warehouse for a couple of years after being imported and then had occasional use over 3,000km/one year by the previous owner.

Also, all belts, tensioners etc were replaced when I purchased it - this was a precautionary measure as the belts were original (i.e. 19 years old), even though the car had only 66,000km on the clock.

Any ideas would be most appreciated!

Cheers!

Mike

[Moodles2]

Mine makes noises at idle as well, but don't hear it while in motion. I'd have to hear what yours makes to make a comparison though.

[Aazzy]

Can you find what area the noise is coming from? It could possibly be a noisey tx valve. I've got a 7 series BMW that hoots honks and ticks occasionally, turns out its a pressure valve that causes weird noises as the gas passes through it, reading up a little I found that the spring that the gas is forcing open gets weak and vibrates.

[mjtown]

Hmmm... Interesting! I'll try to ascertain exactly where the noise is coming from.

Where is the TX valve located?