Best Answer

My car was making a noise, although I would describe it as more of a "hissing" sound, from the heater/AC control panel. It turns out to be the heater control assembly that was bad. I was told another possibility when you hear that noise is the water control valve.

sounds like a system with vacuum controls( found in higher price/luxury vehicles ) for changing settings...def.,floor/heat,vent,etc. a cracked hose-or a hose that has popped off of the 'nipple' it fits on. does it change when you change 'mode-heat,def.,etc? also, there is a ' manifold ' where all the air tubes are joined and feed vacuum to move doors,etc. for heat-def. etc... somewhere under dash-passenger side-or near center that can leak at main vacuum feed. it looks like an cow's udder-clear plastic air lines connect there and go to respective controls for heat, def.,vent,etc. move the hoses a bit- with car runnuing-listen for change in volume of 'hissing'. of course-this problem could be at the control valve in the dash where you make the desired changes for heat,def., etc. the control valve is expensive- i have bought/sold vehicles for 40 years. i am a supporter of 'junk yards ',auto recycling businesses. they will pull the part-now you need to find an installer- this is a bit complicated,based on vehicle and location of hissing all of the options for heat,def., etc. operate correctly-try runniong the system "thru the paces" a few times and listem for changes,location-as i said before-good luck...

User Avatar

Wiki User

โˆ™ 2010-11-19 04:55:25
This answer is:
User Avatar
Study guides

Add your answer:

Earn +20 pts
Q: What would cause a whistling from the heater?
Write your answer...
Still have questions?
magnify glass
Related questions

What would cause a whistling noise in a 1994 Pontiac grand am?

A whistling noise indicates a vacuum leak.

Would the fuse in the heater relay cause the heater to leak into the car?


In a Windstar van what would cause a persistent whistling sound if not the belts or the brakes?

vacuum leak

Is whistling voluntary or involuntary?

voluntary, you cause your lips to form the shape to whistle, and cause the air to be pushed out. if whistling were involuntary, you would do it without making an effort (like your heart pumping, digesting things, etc)

You are hearing a whistling noise on your 1999 Ford F150 What would cause this?

The head gasket is about to blow.....Typical ford..

What could cause a whistling noise while running air conditioning?

A bad compressor belt can cause a whistling noise while running the air conditioner. A bad engine can also cause this noise.

What would cause a whistling sound like a distant fire whistle in the rear of a 96 Cavalier?

Plugged catalytic converter

What would cause truck to make loud whining or whistling sound?

Check the fan belt; it may need to be tightened.

What would cause a water heater to leak inside the case?

It rusted out

What would cause a whistling sound in a GMC Pickup 1993 only when the engine is warm?

"Whistling" sounds are generally vacuum leaks. Start around the EGR valve and/or air intake de-icing assembly.

What would cause whistling in a kitchen sink faucet?

Try clreaning or replacing your faucet aerator. The faucet doesnt remember the words.

What would cause a Loud high pitched whistling noise in 93 Chevy s10 pickup?

Sorry forget to mention it in the motor.

People also asked