07 High pitched squeal feedback sound with AC on

[redder]

Is the random high pitched noise normal? I noticed that the noise also occurs when ac is off.

[Black Pearl]

Originally Posted by redder

Is the random high pitched noise normal? I noticed that the noise also occurs when ac is off.

Is your defroster on? The AC turns on automatically when the defroster is selected. I have never heard the squeal when both the AC and the defroster is off.

I think what is happening is that the computer senses a certain load and RPM on the engine and it cuts back the compressor and the squeal is a result of the refrigerant cavitating in the evaporator. Mine usually does it on a hill at about 3000 rpm, AC or defroster on.

[redder]

Originally Posted by Black Pearl

Is your defroster on? The AC turns on automatically when the defroster is selected. I have never heard the squeal when both the AC and the defroster is off.

I think what is happening is that the computer senses a certain load and RPM on the engine and it cuts back the compressor and the squeal is a result of the refrigerant cavitating in the evaporator. Mine usually does it on a hill at about 3000 rpm, AC or defroster on.

Thank you for the reply.
The blower has always been on when the noise occurs but defrost is not always selected. It does seem to happen more when the cruise control is on while going up a hill.

[Black Pearl]

I think we must be experiencing a different noise, mine only occurs when the AC compressor is running (AC or Defroster). If I have the AC off and the dash vents or floor vents selected, it does not make the noise.

[huangw]

My V is also making this high pitch noise. Today, I've heard it about 6-8 times driving around town.

I'm taking my car to the deal next week to see what they have to say. I've seen a few posts saying that their dealer couldn't do anyting about the noise b/c Honda haven't instructed them on how to fix it, yet. Don't think Honda is acting on it quickly b/c it's not a safety hazard. I hope this problem will resolve soon or else this will be my last V.

[2RedV's]

Originally Posted by huangw

My V is also making this high pitch noise. Today, I've heard it about 6-8 times driving around town.

I'm taking my car to the deal next week to see what they have to say. I've seen a few posts saying that their dealer couldn't do anyting about the noise b/c Honda haven't instructed them on how to fix it, yet. Don't think Honda is acting on it quickly b/c it's not a safety hazard. I hope this problem will resolve soon or else this will be my last V.

It may be that the engineers are having a tough time locating the source and finding a repair. New parts may need to be engineered, from scratch and prototypes built and tested. Then then new parts must be sourced out for production, shipping, etc.

[magicmikef23]

^This is exactly whats going on. I have been having the same problem and a tech at my local Honda dealership said they have seen a lot of the CRV's with this problem and its an expansion valve that needs to be replaced. I have been waiting for over a month for the part and decided to call Honda customer service to see what was up. The customer service rep was very nice and explained that they are waiting for a shipment of the expansion valves from Japan, but Japan will not ship any until they are 100% sure it will work. FWIW there are different symptoms with the expansion valve issue. It could be high pitch speaker feedback or just a squal or knocking coming from under the CRV while the A/C is running. There was a post on the honda-tech site about the problem. I will see if I can find it and post a link.

[luckyray]

Thats hilarious , I find the injection of humour necessary. There is rule in the IT service industry i work in. If u cant reproduce a problem, there is no problem. I usually take a mechanic on test drive and let him see /hear it...

[SuziQ]

Originally Posted by Nick

Yes! My wife's 2007 makes this noise. We thought it was the radio but it's interesting that you hear it with the radio off. It seems quite intermittent and random. I would love to figure out what it is and how to fix it.

My 2002 CRV does the same thing! The noise does come through the radio. However, don't laugh! I noticed it happens whenever I'm at a McDonalds drive through and is the loudest when I'm right by the cashiers window. I think it's interference from the wireless headsets they wear or something.

[dani07crv]

[quote=huangw;7010]My V is also making this high pitch noise. Today, I've heard it about 6-8 times driving around town.QUOTE]

Re: whining sound - me too. I'm experimenting and I think it has to do with the fan. My whine lasts for several seconds and is intermittent. Although I think I have detected a pattern when accelerating uphill. Usually I keep the fan on at the first dot and if I turn it off when the whining starts, it stops. I'm going to try a full ride where I'd normally hear the whine with the fan turned off and see if that helps. Going for 5K service next week so if anyone knows anything specific about this problem it would be a great help. Thanks!