Bmw Ac Hissing

If the valve is working properly, you should hear a hissing noise from the valve with the engine running at idle. Sign in to review and manage your activity, including things you’ve searched for, websites you’ve visited, and videos you’ve watched. AC Hissing noise General E46 Forum. considering carb cleaner spray can spray can in the place of the hissing gone the engine doling out and once you listen the engine stall or rev superior there is the leak ,could be a bad vacuum hose bad gasket on the manifold. “My BMW doesn’t seem to be overheating initially, but it does keep losing coolant, which eventually causes an overheating situation. It has an audio recording function but this came across as modest, with background hissing making it difficult to pick out low volume sounds. Long story short, air conditioner compressor noises are usually bad news. Seems to be worse when using heat as opposed to the AC. Butim not too sure. A manifold gauge set measures refrigerant pressures inside of an air conditioning system. The thermostatic expansion valve (TEV or TXV) is erroneously considered by some to be a mysterious and complex device. From Cornhill to Grand Cairo by Thackeray, William Makepeace, 1811-1863 - Free download as Text File (. My AC conditions developed a pin hole leak along the seam/braze. My 2005 m3 coupe has this air hissing noise inside car seems like it's coming from passenger side behind dashboard. creates an AC voltage from the input DC voltage. There are a few different causes between gas and diesel engines. But says either front or rear evaporators run separately and either could be the real problem. There is an ond and off hissing sound from the center of the - Buick 2009 Enclave question I have a 2001 BMW. But first, let's look at how low airflow causes your air conditioning system to produce that whistling sound: Why low airflow causes whistling. If it’s hot in a situation of car air conditioner blowing hot air , then it’s an engine problem. Be confident in knowing we offer a hassle free return policy. So, let's find out why the car AC not blowing cold air after recharge. Comments: Our 1997 BMW 740 IL, when you turn air conditioning on, it blows very low air even at high speed, but after about 10 minutes it works fine with optimal cold air. Uncovering The Causes Of BMW Suspension Noise. 3L V6 Engines. This is a perfectly normal condition when the engine is turned off as the pressures equalize within the a/c system. The brake pedal is low and spongy. Think of it like you checking account. At Byrd Heating and Air Conditioning, our technicians understand the various components within a heating and cooling system, so we know the proper way to take it apart and get to the coils and compressor. First, the air conditioner may not be the problem. This walkthrough will help you understand the various causes of misfiring and identify which ones you can handle yourself. Hissing only happens when fan is on. A fantastic car. Mechanic ran on AC tester for 2 hours with no leaks found in system. Sign in to review and manage your activity, including things you’ve searched for, websites you’ve visited, and videos you’ve watched. The service of evacuating and recharging this system may be all that is needed to get that air blowing cold from the vents in your BMW. When I use only the vent, the noise isn't there; only when I actually turn on the A/C. Maintaining your own truck or car brakes is an optimal way to ensure they're always in top shape. But if it has too much, it won't work either. I have a 2002 Honda Accord coupe with 130K miles on it. The blower won't come on for 30-45 minutes after the AC has been turned off, but after that it seems to turn back on fine. How to find a car's low side pressure port is one of our most frequently asked questions. Auto Cooling Solutions is the leader and #1 Manufacturer. The hissing sound is caused by equalizing pressure. Uncovering The Causes Of BMW Suspension Noise. It sounds like air escaping from somewhere however I can't seem to find where it's coming from. I already replaced the puller fan and it still doesnt work. The good news is this doesn't always spell trouble. A fan blade or two may have broken. What you can do is to bring your car back to PML and complain aircon not as cold. Chrysler 300 convertible Mopar 1969 lasts owner 15 years 65k on the clock 440 coupled to the automatic box white swivel bucket seats matching roof bronze paint work magnum wheels white walls all round good driving car not many of these Mopars over here on the boat arriving soon about the end of the. April 19, 2011. Reason why it blinks is because there is no oil (lubricant) and GAS left in AC system. To advertise, contact our sales department by calling (650) 948-9000 or email [email protected] To be able to service and repair an AC system, read through all three articles. Sounds like its coming from the wheel/brake on that side. Here are a few possible explanations behind the hissing sound in your AC system. Sinister Diesel is the only place to shop for the best diesel performance parts including turbos, cold air intakes, and more! Shop today!. Also, if you mess around a bit you'll find that the position of the steering wheel makes a difference with getting the key out as they get high mileage, all normal for a Volvo. Hissing with key in the on position but engine off. Seems to be worse when using heat as opposed to the AC. Vacuum Booster Operation. If your air conditioner is freezing up due to undersized ducts, you should call an HVAC contractor and have them take a look at your problem and offer their suggestions. Labels: behr bmw parts, bmw auto parts, bmw replacement parts, bmw salvage parts, bmw suspension parts, Fix-A-Dent Auto Body bmw spare parts, parts foe bmw, parts for bmw cars, varis bmw parts As is known, any car starts to rust in due course is the fact. This is the is the weak spot in every AC system. Alternator whine is the granddaddy of car. re-gassing will only mask the problem and not fix it. This is my wife's and I don't drive it often, so I am unsure if the hissing is normal or part of my ac problem. Over the past week I have noticed when turning on the A/C or defroster it would make a slight hissing sound for the first few seconds. In Tamil Nadu, a young man was driving his BMW on the Highway,on spotting a snake on the road, he tried to run over it. The hiss also goes away if I hit the AC button. In Tamil Nadu, a young man was driving his BMW on the Highway,on spotting a snake on the road, he tried to run over it. Maintaining your own truck or car brakes is an optimal way to ensure they're always in top shape. When there is a crack on the diaphragm or the O-rings of the brake booster, you will hear air hissing sound near the brake pedal. If you shut down engine and re- start the car AC goes through same cycle, it takes about 10- 15 mins for cold air to blow properly at proper speed. Contacting a professional technician for an inspection is the best step to take. Whatever you set the warm idle speed at in the engine setup of the handheld your engine will run. The current one is my A/c started hissing first use this year. At Bimmerforums, you will find technical how-to information maintenance specifics audio advice wheel and tire combinations and model specific details not found anywhere else. If the AC blows cold then warm condition was caused by moisture in the system, you won't notice a decrease in airflow and you won't see a puddle of water after shutting off the vehicle. This applies to when the AC is on vs off, electric fans on vs off, and transmissions in park vs neutral. WHAT IS THE CORRECT PRESSURE FOR MY CAR 2009 Traverse started blowing warm @ 35k miles. If you have air conditioning it's condensation from your AC spilling into your vehicle instead of outside on the ground. This typically happens if the engine is too hot, so be sure to check the engine temperature. A hissing noise after turning the car off is actually caused by equalizing pressure , this is made by the Freon moving from the high-pressure side of the compressor down into the lower pressure side and is a completely normal occurrence and sound. Here's our foolproof tips for finding yours. A brake booster needs the right amount of vacuum to operate. Here's how to get your system "just right. When I turn it off, no sound at all. Low pressure in your AC unit can be a sign of a leak, as can the actual coolant draining around your vehicle. If you have any questions about your V6 Mustang or just want to connect with other V6 Mustang owners around the world, you have found the best place on the internet to do that. So, if it is over 90 degrees outside and you turn on the AC, the compressor may run on its own to bring up the necessary pressure to cool the cabin. This can range from a mild hissing noise to a loud hissing or a noise some describe as a "scream. But sometimes a supply register can be loose or broken, causing the noise. And while it's never convenient to have a broken air conditioner, a yearly inspection and tune-up can prevent future problems. Another cause of AC blows cold then warm. Any new hissing, groaning, whistling, or other nusiance sounds should be investigated right away. If the valve is working properly, you should hear a hissing noise from the valve with the engine running at idle. What you can do is to bring your car back to PML and complain aircon not as cold. Every once in a while I receive a call from a customer that is hearing a hissing noise coming from their air conditioner. Uncovering The Causes Of Suspension Noise On BMW Vehicles. once my 2005 (V6) Ford Mustang is started and running, I am hearing a continued hissing noise which gets worse once the car is driven. Unless you put an ear up to the line, the air handler is louder. BMW E38 E32 Air Conditioning Regassing 730i 735i 740i 750i 7-Series "Tim Meek" Timm AIR CONDITIONING REGASS There is a kind of rumbling / hissing noise and. Mini Coopers can be great fun to drive, but sometimes problems do crop up. Offering the best in BMW/MINI Cooper and Cooper-S parts and accessories. Like the title says, the AC was absolutely freezing the last time I drove the car, today it blows out warm air. At such times, you should call for professional an aircon servicing company to restore the health of the air conditioner. Weird noise when AC switched on General E46 Forum. If your air conditioner is making a buzzing noise that is loud enough to become a distraction in your home, chances are that something is wrong with your unit. This covers the seven most common problems we run across in servicing Mini Coopers. We offer you the most comprehensive line of high performance air conditioning components available. Rear AC Block Kits, Rear AC Replacement Line Kits. The brake pedal is low and spongy. I am, however, concerned about how it lost the refrigerant in the first place. It's been in the mid 80s this week with high humidity, the AC has functioned perfectly for me in the front with plenty of room to spare (I'm sure my AC will keep me cool in the height of summer, even with my previous comments to the opposite), but I'm sure if I had guests in the back they wouldn't be happy, methinks someone needs to come up. I hit the curb on the front driver side tire. WEDNESDAY, AUGUST 21, 2013. However, that same system is constructed out of so many components that are buried within the hood and bowels of the vehicle that it's sometimes difficult to. Start with the fan speed turned to its highest setting. And believe it or not, it involves using sound to find the leak. It runs by temperature needs. The hissing noise is due to the A/C evaporator being starved of enough refrigerant. The booster uses a rubber diaphragm and a push rod. A brake booster needs the right amount of vacuum to operate. Toyota/Lexus Timing Belt Service On 3. Manifold Gauge Readings. Hissing present, air is warm. Many air conditioner repairs can be avoided by consistently changing your filter. E46 330ci restricted performance (re-posted) Reply BMW have quoted me £340 to change the MAF but as you can appreciate without knowing that it is definitely the problem I’m not keen to do. Too much air pollution and smoke coming out of your BMW's muffler is a good indicator of muffler replacement. to multiple accessories like the air conditioning, power steering and alternator. I hear a hissing sound, seemingly from behind the dash, and only when the car is set to vent. Page 1 of 2 - Hissing sound from aircon - posted in Maintenance & Repairs: My aircon has been doing the darth vader ever since i replaced the aircon clutch and topped up the gas and aircon oil. It sounds like. so I pulled over and shut off the car. Something may have fallen - or climbed - into it. AC Test Gauges. Before the winter I noticed a small drip under the front drivers side and my mechanic said that the leak was coming from my a/c compressor which would have to be replaced. Every once in a while I receive a call from a customer that is hearing a hissing noise coming from their air conditioner. Unless you put an ear up to the line, the air handler is louder. re-gassing will only mask the problem and not fix it. Today, about a couple hours ago, the brake pedal started to get very hard to push and wasn't stopping the car very well. The blower won't come on for 30-45 minutes after the AC has been turned off, but after that it seems to turn back on fine. Recently changed the oil. If your filter is dirty and clogged, it can cause many issues with your unit. The vacuum pump is attached to the engine and maintains the pressure between in the outside air and the engine intake manifold. 6 weeks ago I took my car in for a first service. If there is too. I have the same issue, it's the bearings on the circulation fan starting to go. If the valve is working properly, you should hear a hissing noise from the valve with the engine running at idle. One of the most frustrating aspects of car audio is noise in the system. Default is defrost with no vacuum. An auto air conditioning leak is probably the most common problem found when your car AC system isn't blowing cold air. Update: Did some snooping and it doesn't seem like its coming from the exterior of the vehicle. The hissing sound is caused by equalizing pressure. Even so, most leaks are small and hard to spot. Most likely cause: Your compressor. If you think your car air conditioning is not blowing cold enough the first step is to check the output temperature at the center duct with a thermometer. The check valve is an important part of any air compressor. Contacting a professional technician for an inspection is the best step to take. Love playing music, games and videos on your computer? Wait until you try it with the Companion® 2 Series III multimedia speaker system. The hiss also goes away if I hit the AC button. Electrical failures caused by connection to an improper power supply, i. our AC season is really about 4 months long, with it really hitting hard in June and July, then the rest of the year we may not use that equipment, training, or skills at all. So what does a hissing sound mean? It can mean a few things, but no matter what the exact problem, it's important to have your Dynamic Mechanical Heating & Air Conditioning expert manage your air conditioning repair services in the Bristol and in New Haven whenever you hear a hissing sound coming from your AC. I guess I need to replace the booster, right? No. Then use a leak dye light (black light) and check to see where a leak is and fix as required. Hi everyone…. Hissing is the sound it makes to increase the pressure in the system, and as it gets lower and lower, the hissing will get more frequent. also my electric fan (puller fan) is not turning on when the air conditioning is turned on. At Byrd Heating and Air Conditioning, our technicians understand the various components within a heating and cooling system, so we know the proper way to take it apart and get to the coils and compressor. No more dash hissing and the AC is still nice and cold. You need to find the leak first. wikiHow's Content Management Team carefully monitors the work from our editorial staff to ensure that each article meets our high standards. Hissing coming through ac vents. One of the most frustrating aspects of car audio is noise in the system. After doing some diagnostics, I detected audibly a hissing sound coming from the low input port, leading me to believe the schrader valve is leaking. Servicing 1996 To 2005 Volkswagen And Audi Vehicles. If you have air conditioning it's condensation from your AC spilling into your vehicle instead of outside on the ground. i called bmw north america and spoke to them about my issue and it did not show my car having any recalls. More so if the unit is running in tropical climate, because sultry weather conditions are not exactly favorable circumstances for air-conditioning units to run if they are not used and serviced properly. Pay attention to the sound your car is making, and where it is coming from. Failing hoses make hissing noises or leak fluids and most of the time this noise is barely audible above the engine hum so you have to listen closely. Last summer it was blowing - BMW 2001 325 question. I thought it was the AC to condenser line, but not the case, despite my truck not coming with the bracket that GM started adding to later models (thanks beta testers). You should take it to a AC guy to hook it up to gauges. The lines begin to leak where the aluminum part of the lines run into the rubber line. While every factory Ford GT40 is special, some are more special than others. it was quiet before the change but now there is a very audible hissing sound every 1 minute does this mean there is not enough gas? is it causing much strain on my compressor? should i go get it. The only way I get it to turn off is when I turn the fan off or press the A/C. It got to be we could never know if some hissing was normal or not - because for two years there was always at least a little. Hissing or bubbling: A serious refrigerant leak can produce hissing noises in the compressor. Repair : A repair shop will tell you the entire compressor needs to be replaced, which also necessitates a full evacuation & recharge of the entire AC system and replacement of the drier/filter. It will also damage the relay. But before you call a Lawton, OK professional for help, of course, you want to be absolutely sure you have this problem. Refrigerant leaks – the amount of refrigerant in your air conditioner has to be carefully balanced if you want to keep your air conditioner running smoothly. The brake pedal is low and spongy. It started with intermittent hissing coming from the dash. AutoZone stocks the best tire valve stems for cars and trucks from brands such as Slime and Xtraseal. Here is a great video showing how to find a vacuum leak under the hood, take a watch. Here's how to get your system "just right. Slow acceleration starts at 18 seconds up to 30 mph. Be confident in knowing we offer a hassle free return policy. Contacting a professional technician for an inspection is the best step to take. Identifying Weird Car Noises. Chrysler 300 convertible Mopar 1969 lasts owner 15 years 65k on the clock 440 coupled to the automatic box white swivel bucket seats matching roof bronze paint work magnum wheels white walls all round good driving car not many of these Mopars over here on the boat arriving soon about the end of the. Then, I attempted to turn on the air conditioner on in the car last week and again – very bad squelching noise Read moreCompressor Rapidly Cycling On and Off in Car Air Conditioner. There are many reasons why your AC could be making noise, some easier to fix than others. The tapping end cleans and restores the interior threads, and the die end cleans and restores the cap threads. My air conditioner on my 2003 BMW 325i keeps on going on the fritz. Screen brightness: on an X31, a hissing sound is started whenever screen brightness is not full. With nothing more than a multimeter and a methodical approach, you should be able to find out what's wrong getting your car up and running in no time. It completely stops if AC is switched off. You need to find the leak first. It is extremely reliable and it very fun to drive. The return line (uninsulated) line coming from the evaporator has a loud hissing sound. pete323 wrote: My brake pedal in fairly soft in my e30 316 compared to my 98 e36 Are the pedals on e30`s soft? (Travel far) Also when sitting idle when you press the brakes there is an air (hiss) sound from passanger side. re-gassing will only mask the problem and not fix it. For more. When the AC is running, every 30 seconds or so there is a hissing sound that I can hear coming from the vents. So I was at the movie's Sunday to watch snitch. The hissing is from low ac gas. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. If you notice a loud, buzzing noise coming from your air conditioner, chances are your unit is malfunctioning. I turned on the other A/C unit and it does not have the same sound. nothing different, same synthetic oil I have always used (and suggested by the dealer). Over the years the manifolds have gotten more sophisticated and. After going back and forth with ford for a couple weeks, sound got worse, followed by warm air on the driver side and cold air on the pass side with ac on. But if your air conditioner sounds like it's screaming, turn it off right away. wikiHow's Content Management Team carefully monitors the work from our editorial staff to ensure that each article meets our high standards. Alternator whine is the granddaddy of car. Hissing is the sound it makes to increase the pressure in the system, and as it gets lower and lower, the hissing will get more frequent. When the hissing stopped, air was cold. Your Tire Valve Stem Does More Than You May Think Tire valve stems maintain air pressure and make it possible to inflate or deflate tires. First, the air conditioner may not be the problem. 2002 BMW 325i air conditioning problem I need some help finding whats wrong with my car. You’ll enjoy performance that’s significantly better than your original speakers—and it’s our most affordable computer speaker system. so I pulled over and shut off the car. If the hissing was the refrigerant leaking out, it would have blown hot air immediately. Mini Coopers can be great fun to drive, but sometimes problems do crop up. I had the engine idling at a fast idle when the pressure relief valve on the A/C compressor blew open and released all the refrigerant to the atmosphere! There was a VERY LOUD hissing sound! I was kind of BLOWN AWAY by this event!. The Five Overlooked Car Maintenance Items How Preventative Maintenance Can Help You Avoid Catastrophic Repair Costs. Please do your research. How to find a car's low side pressure port is one of our most frequently asked questions. Although this hissing noise, sounds like a bad noise, it's actually a good air conditioning noise. From time to time, you may notice your air conditioner leaking water outside. Just given the car at the dealer. Had Freon added to system worked ok for 2 to 3 days and then nothing. Is your BMW blowing hot air when you want AC? Not getting enough hot air when it's cold out? Well we have the heater cores, heater valves, blower motors and. don't worry if your car is not the same, most Japanese starter motors are very similar and this guide will get you through most of them. The sound stopped when the AC was turned off. My buddy was driving my 2006 Chevy equinox awd the other day when the car got hot and cut off they put water in it Jumpstart ed the car and drove it home it would not drive over 25mphalso there's a rattling noise coming from either the top or bottom in front of motor the car will run and stay running with no problems except the rattling noise sound like a chain being pulled down set of metal. An illustration of troubleshooting a ticking noise coming from a running car by applying the process of elimination. It started with intermittent hissing coming from the dash. Some cars have a shut off feature that will disengage the a/c compressor if your engine is under duress. like 15-20 minutes. The pressure created helps run different systems like the ventilation and power braking. Sound: A hissing sound coming from the area around a gas appliance is a sign of a gas leak. Rattling sounds indicate loose or busted baffles inside. A hissing sound is not always present either. Car is a 2004 bmw z4 with 68,000 miles. Notice that high-pitched rattle coming from somewhere underneath your car? If it. The basic components of an automotive air-conditioning system includes the compressor, evaporator, expansion valve, condenser and accumulator, along with hoses and fittings. Without hearing this "hissing noise" it's difficult to assist. “My BMW doesn’t seem to be overheating initially, but it does keep losing coolant, which eventually causes an overheating situation. 07 uplander no a/c hiss from vent. When it is not, which of course occurs on the most brutally hot day of the year, the A/C suddenly becomes a cruel joke, blowing warm, stale air into your vehicle. Thanks for your help guys, the mecahnic I spoke to specialises in AC, and said he will check for leaks for empty the remaining gas out and reharge it, so hopefully this will resolve the issue. Many air conditioner repairs can be avoided by consistently changing your filter. The different sounds range from whooshing to buzzing and everything in between. The OBD-II code P0101 is set when the signal from the mass air flow sensor is out of expected range, or in other words, the MAF sensor doesn't work properly. A good car radiator is vital to the operation of your car. How to find a car's low side pressure port is one of our most frequently asked questions. With nothing more than a multimeter and a methodical approach, you should be able to find out what's wrong getting your car up and running in no time. Any new hissing, groaning, whistling, or other nusiance sounds should be investigated right away. At such times, you should call for professional an aircon servicing company to restore the health of the air conditioner. My car has an automatic transmission. Last summer it was blowing - BMW 2001 325 question. BMW Exhaust Muffler Parts Online. Exhaust Gas Recirculation Valve (EGR) problems, Alfa Romeo Exhaust Gas Recirculation Valve (EGR) problems fixed, Audi - 1. Page 1 of 2 - Hissing sound from aircon - posted in Maintenance & Repairs: My aircon has been doing the darth vader ever since i replaced the aircon clutch and topped up the gas and aircon oil. The car won't start, not even click, but everything else works fine in the car. Actually the TEV performs only one very simple function - it. Toyota/Lexus Timing Belt Service On 3. Last summer, my AC went warm. Had Freon added to system worked ok for 2 to 3 days and then nothing. Engine is very rough on idle, very shaky. Seems to be worse when using heat as opposed to the AC. You may also see puddles of liquid under your car in the morning which means something is leaking. I thought it was my new tire's so I started looking around and realized it was coming from the steering box area? When I turn the wheel the noise stop's ,But if I let it idle Hissing start' back up. The DISA valve is a component situated in many BMW intake manifolds, and is vital to the smooth operation of the engine. When I first start my car the AC will only blow warm air. And believe it or not, it involves using sound to find the leak. It has remained cheap to buy, run, tax and insure, making it the. I think your system could be just fine. re-gassing will only mask the problem and not fix it. The Blower motor on my AC unit turns off at random times while the outside unit continues to run which is causing the coil to freeze up. Locate the car's vacuum lines, and look them over, checking for unplugged connections, as well as signs of wear and cracking. Save on Brake Boosters with great deals at Advance Auto Parts. Top Power Brake Booster Questions. Data helps make Google services more useful for you. It is audible through the air vents, it's louder on a hot day, and comes on every 20 seconds and runs for six seconds. A failed or failing or sticking valve inside the compressor motor; Abnormally high pressures on the outlet side of the compressor motor activate an internal pressure-relief safety valve. This is #1 on the list. Long story short, air conditioner compressor noises are usually bad news. Power supply: a T61p is known to have the sound if a 90W power supply revision 01 is used. The official Yamaha 350 racer, Jarno Saarinen, rode to victory in the 1973 Imola 200 Miles after having won that year's Daytona 200. Then, I attempted to turn on the air conditioner on in the car last week and again – very bad squelching noise Read moreCompressor Rapidly Cycling On and Off in Car Air Conditioner. Mini Cooper: Why Doesn't My Air Conditioning Work? Driving without air conditioning in the summer is simply inconvenient and uncomfortable. My friend, who has. When it is not, which of course occurs on the most brutally hot day of the year, the A/C suddenly becomes a cruel joke, blowing warm, stale air into your vehicle. It can be helpful to take a look at them with the vehicle's engine running so that you can listen for whistling or hissing sounds indicating a leak. A lot of people suggested that when they press the AC button on their Mercs the lights blinks for few seconds 5 times then stays RED, whereas it should turn off. If you own, or know someone who owns a MINI Cooper S (R56) car, from 2006. Yeah I'll have to go through all those, But it only hisses if I jump the Compressor Clutch to force compressor to run. There is no smoke, but I can clearly smell it coming out of the vents. If your power steering pump is making noise and you can't get a new one, the best thing to do will be to keep it full of fluid to make sure no further damage occurs. When I start the car I dont hear anything, then when I put into drive I can hear the hissing like a. 2003 bmw e46 m3 coupe If you have the AC. If this is your first visit, be sure to check out the FAQ by clicking the link above. Sound: A hissing sound coming from the area around a gas appliance is a sign of a gas leak. As the temperature drops, so do your chances of your car running properly. if it does rotate and your not getting cool air then you may have one of three things. AC lines problems occur on any car with AC. This is strange. Twice they replaced the dash controls. Also please check out the statistics and reliability analysis of Buick Enclave based on all problems reported for the Enclave. Butim not too sure. And believe it or not, it involves using sound to find the leak. It sounds like. USUAL CAUSE The usual cause of abnormally high idle speeds are vacuum leaks or an inoperative idle speed control motor. Although this hissing noise, sounds like a bad noise, it’s actually a good air conditioning noise. Then, I attempted to turn on the air conditioner on in the car last week and again - very bad squelching noise Read moreCompressor Rapidly Cycling On and Off in Car Air Conditioner. First, the air conditioner may not be the problem. Whenever there is a repair that needs to be completed for my car it is usually very expensive. The good news is this doesn’t always spell trouble. We go out of our way to carry every major line of BMW 1 Series blow off valves, so that whether you are looking for a Greddy blow off valve or a HKS blow off valve or anything in between, we've got it for you. This system should be using vacuum from the engine to open and close the air diverter (blend) door inside the dash. Vostro clearance Reach your full potential. As of today the hissing sound is constant and the air is not blowing very cold at all. Without hearing this “hissing noise” it’s difficult to assist.