g_bhavana said:When I start the PILOT and change the vent mode so that air is coming in at the legs only (automatically the A/C button turns on), a really loud noise (similar to scrunching metal) is heard. Has anyone else had this problem?
Mr Hambone said:I have the same problem with my Pilot, and I have an answer as to why it happens.
Air conditioning compressors only run when the air conditioning is turned on, and they use a clutch to transfer power from the engine fan belt to the compressor. The air conditioning clutch is a friction-type clutch which uses metal discs. These discs can collect rust when it sits overnight in certain conditions. Don’t worry – the rust is not bad, just a normal thing that happens. When you turn the air conditioning on and engage the compressor for the first time with the rust on the discs, the sound you hear are the discs “cleaning” themselves of the rust.
The same thing happens with disc brakes. Ever notice first thing in the morning you’ll see a light coating of rust on the rotors? When you use the brakes for the first time, you’ll hear a squeaking sound – that’s the rust interfering with the brake shoes. Once the rust is gone, all is quiet.
So do not be too worried – it’s a normal thing. But if the noise gets louder and is more persistence (stays on the whole time the AC is on), then it’s time to worry.
Hope this helps, and makes sense!
PS – My source was a very helpful Honda tech from my local dealer – thanks Rob for solving the mystery!