Oil pumps circulate oil throughout the engine. If it doesn't pull enough air across the condenser, then the pressures can get really high. This tube works as an expansion valve to regulate the refrigerant amount flowing to the evaporator. Sounds like a blockage in the high side line to compressor discharge oort. The AC Heater box or plenum is located under the dash. "Air-conditioning servicing system and method." The rear ac uses a TXV/H-Block and it sounds like the valve is not working. 04-09-2005, 01:47 Smaller air conditioners or refrigeration equipment whose design does not include a refrigerant accumulator are at increased risk of damage from overcharge, liquid slugging, or oil circulation problems. Lets understand what Doors control the direction of the airflow created by the electric blower motor. If the valve sticks closed, there will be no heat. If the system is continuing Sometimes high temperature causes oil pressure to drop. Come join the discussion about performance, engine swaps, modifications, classifieds, troubleshooting, maintenance, and more! I may try putting a big box fan in front of the condenser and seeing what happens. Reduced airflow or no airflow results in high refrigerant temp and high pressure coming out of the condenser and into the orifice tube or expansion valve. Usually, to use a belt without ac, you need to remove the compressor as if it didn't have ac. Record the pressures. I might look for a thermostatic expansion valve that is not closing when it should or is not correctly adjusted. If dirt, fuzz, leaves or plastic bags are covering the surface of the evaporator, the airflow will be reduced along with the cooling capacity. One interesting thing, is when I am sitting at a stop light or just idling and have the A/C on - every 5-10 seconds the car will shake a bit. Question: I charged the A/C system. Both of the schrader valves are leaking. Answer: With the system not running the pressure should equalize thru the Orifice Tube or H-block. Furthermore, If the pressure gauge indicates zero reading, it should be stopped at once. Depending on the system, there are at least three to four doors controlled by cables, vacuum actuators or electronic motors. 1. 2002 Mazda 626 2.0L 4cyl. (A-1 Compressors 2009). Does that make sense? Low head pressure may occur simulataneously with high pressure on the suction side of an air conditioner, heat pump or refrigeration system compressor system. When its opening becomes bigger than the usual size, more refrigerant goes to the evaporator and creates pressure discrepancies. Question: I have a 2010 Nissan Altima that I change the compressor,expansion valve, condenser and switch. Since it does cool I would think it is close to being charged. Twice I have tried to charge the A.C. system to the proper pressure. 2006 dodge Durango slt 4.7l with front and rear ac. This filter is often overlooked until it is entirely plugged up and allows very little airflow into the cab. Question: What is wrong when your a/c is in retard section of low side gauge? Any ideas where to go from here? Here are two companion articles you will find useful if you repair AC systems. He is also providing training to mechanics and works as a Senior Mechanic of a well-known organization. Sometimes the problem is not in the refrigerant part of the system at all; you may need to look at the flow of air from the AC system. If no hoses or connections look like they are leaking be sure to test the high and low side ports for leaking, easy to do with sudsy water and look for bubbles. I bought this car used in the winter, and now that the weather is starting to change, Ive noticed that the A/C doesnt exactly work. (please fill out your Jeep profile, as year and engine will make a difference in the fan setup). The lower high side pressure may be from an undercharged system and the TXV is keeping the low side at 30 PSI. After the system runs for a while, raise the RPMs up to about 1,500. Low side of Gauge reading is 40-50 psi. Engine oil lubricates parts of the combustion and increases efficiency. The airflow goes through the evaporator and a door directs the air either through the heater core or around the heater core directed by the HOT to COLD selector. Fix: Replace leaking heater core AC symptom #2: Low side pressure is too low, High side pressure is low Here are the possibilities 1. No hot water valve is needed because in cool mode the door closes off airflow through the heater core. Servicing an Auto AC System and Replacing Components. A forum community dedicated to all jeep owners and enthusiasts. Apologies for the delay. Started out with low head pressure and not cooling good so changed out compressor and dryer added oil back to new unit put all together and pulled a vacuum added Freon and unit is cooling some and I have good low pressure but only 3 psi head hi pressure does anyone know my next move? Lets look at some causes of low or zero oil pressure. Didnt read anything on here about normal high side but high low side. Question: I have a 1998 suburban with rear a/c. If the system is properly charged it seems the compressor is not working up to par. Both gauges are reading zero. WebWhat is normal automotive air conditioner pressure? Typical faults of air conditioning systems and fault detection by ARX model and extended Kalman filter. 1. I'll do that tonight. The blockage or stuck expansion valve restricts the flow of refrigerant into and out of the evaporator. Answer: The computer senses the extra load added by the power steering and turns off the ac until the load is reduced. So replacing the defective pump or gauge will be a good idea. Low head pressure may occur simulataneously with high pressure on the suction side of an air conditioner, heat pump or refrigeration system compressor system. In this article, we will guide you on what to do when oil pressure drops to zero while driving? A low pressure cut-off will prevent the - defective or mechanically-damaged copper tubing Condenser fins are clogged, condenser fan isnt running or isnt running at the correct speed (most common cause). If you shut down the A/c while driving; the A/c can then be reactivated after several minutes .TIA .. Edited: Mon June 03, 2013 at 1:03 AM by Need Cooling. On the other hand, there is possibly a huge leak when the pressure is zero. Get the BEST auto repair information Alldatadiy.com and Eautorepair.net are professional-grade shop manualsperiod. Charge with DYE and retest with a black light. Change in viscosity of oil can cause damage to the oil pump. Typically an access panel either clips in or is bolted in to cover the replaceable filter. Answer: The system can't be zero on the high side. Chandra, Arora Ramesh. Does the condenser have bent or dirty fins? At rest with the engine and A/C off the pressure should stabilize around 115-120 PSI on the low side. System must be overcharged or your gauges are somehow connected wrong. Thank you for heling out, anon.Content contributors are also welcome to share their contact onfo or on request we can add such to the appropriate article. Please bookmark this page to make it easy for you to check back for our response. Route checkups prevent major problems. Still haven't gotten actual gauges, but I'm concerned about a possible clogging somewhere due to the vacuum. The pressure at which boiling occurs for the local temperature. The solution to this problem is changing the bearing. what causes high pressure on the suction line on Rheem R410a ? The compressor clutch stays engaged and the pressure readings stay the same. Answer: Sounds like poor airflow across the condenser. The Fora platform includes forum software by XenForo, VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. Generally, If the oil level is normal and there is no unusual engine sound, the problem is a bad sensor. Lets look at some causes of low or zero oil pressure. Tried adding refrigerant, the low pressure needle does not move. Bump, still looking for a response. @Freeman, its not about tonnage. No other leaks were found. According to physics, thicker liquids require more pressure. Where else should I be looking? The filter looks like a small air filter from a car. For cooling to take place, air has to flow freely across the evaporator. It was 85 outside and I'm guessing about 40% humidity. Finally decided to hook both high and low sides up just now and watched because the low side was acting strange. It could be an issue with the orifice tube too. A clogged filter leads to extended oil and thus result in poor combustion. If you missed part I, start here. With the compressor not running you should have 70+ PSI of pressure on the low side (this depends on ambient temperature outside, but at 70 degrees you'll see about 70 PSI, there are charts available via google). 7 Causes Of Car AC Low Side Pressure Zero. In most cases, their diagrams are right from the factory manuals. Observe the pressure gauges. Riffat, S. B., C. F. Afonso, A. C. Oliveira, and D. A. Reay. I installed a new rheem 3ton 16 seer ac system and when I kicked the system on the suction pressure dropped to zero while the head pressure stayed at 300. Drive Accord forum, a community where Honda Accord owners can discuss reviews, service, parts, and share mods. REFRIGERANT PRESSURE DIAGNOSIS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice. Use the leak tester for larger leaks and the dye with a black light for smaller leaks. But the high side is extremely low. I drove around for about an hour with the outside temperature 88 degrees. Is the cooling fan running constantly? Recharge. Take a look at the temperature/pressure chart for your HVACR system for the specific refrigerant that you are using; you'll need to know the ambient temperature as well. Secondly, evaporation can cause the oil level to drop. 4) Blockage on the high-pressure side of the system between the compressor and condenser but before the high-pressure port. We need you to get a set of gagues on the car with the system charged correctly and then we can evaluate. Low side is way to high. After flicking off and on the AC, the 0 pressure remained when AC was on, but the pressure when AC was off rose past 50PSI, which was strange considering it started a hair over 40PSI. The orifice tube has too large of an opening or the o-ring sealing the outside of the orifice tube is not sealing. Also suspect the switch.Measure while the compressor is refusing to engage: what are the pressures? The switch is functioning correctly. Is there a possibility of a leak based off the gauge readings? AC Low Side High, High Side Low: Why Does This Happen? Answer: Sounds like the gauges are not connecting. If the liquid line is not warm on your system you may face these problems. Whats likely the culprit? To gauge the pressure, hook up a gauge set to the AC system and record the pressures of both low and high sides. When a car pump is broken or damaged, the oil pressure drops. Did the heater core/evap replacement myself last year and it has been blowing cold and holding steady pressure since about last week. 1. Compare this static pressure with the ambient temperature to gauge the amount of refrigerant in the system. Also, was your fan on? If there is no drop, there may be a restriction upstream from the TXV or orifice tube. Pricing: ---Eautorepair.net--- 1 month subscription $19.95 per vehicle 1-year subscription $29.95 per vehicle 4-year subscription $44.95 per vehicle ---Alldatadiy.com--- 1-year $29.95 subscription: additional vehicles $19/95 each 5-year $49.95 subscription: additional vehicles $34.95 each Which one should YOU choose? Cengage Learning, 2012. If the pressure is zero, that means the system is at atmospheric pressure and has a If the cabin filter is dirty, the result will be low airflow. Electronic actuators with position sensors are very popular to move the doors to direct the airflow and control temperature. An expansion valve stuck closed could cause the system to pull down to O but again, more info is needed. Our Comment Box is provided by Countable Web Productions countable.ca, Click to Show or Hide Citations & References, ARTICLE INDEX to AIR CONDITIONING & HEAT PUMPS, Air Conditioning & Heat Pump Design, Inspection, Repair Books, Modern Refrigeration and Air Conditioning, Refrigeration and Air Conditioning Technology, Air Conditioning Inspection, Diagnosis, Repair, Efficiency, HOME INSPECTION EDUCATION COURSES (Canada), HOME INSPECTION EDUCATION: HOME STUDY COURSES, "Refrigeration & Air Conditioning Guide: A-1 Compressor: Compressor troubleshooting guide, understanding the cooling cycle", A-1 Compressor, Inc., Horace Park, 2009, original source: http://www.rpctubes.com/images/CompressorTroubleshootingGuide.pdf. Oil pumps circulate oil throughout the engine. The AC and heater operate out of the same box or plenum typically under the dash. Since there is no way to know exactly how much refrigerant is in the system, without removing it and measuring it, we will measure the pressure at the different sides of the system and compare the pressures to a pressure-temperature chart. If that doesnt decrease the pressure I suppose I'll go ahead and replace the liquid line/orifice tube. Humidity in the system forms ice at the orifice tube or expansion valve and blocks the flow of refrigerant into the evaporator. The pressure reading from the low side should be between 25 and 30 psi and the high side between 200 and 250 psi. The same problem arises when the o-ring seal outside of the orifice tube wears out. Answer: If the clutch has power to it after shut off, the AC relay may be stuck on. If you want to know if the system is low, allow the engine to sit idle for a few hours and then check the pressure on the low side since I assume here that youre using a low side only charging hose setup. 3 (2010): 510-520. I did this 2 times and pressure is the on the low and high? Sometimes the readings youre receiving on the gauge can be accurate yet the ACs pressure might not be up to accurate. Come join the discussion about MazdaSpeed performance, modifications, classifieds, troubleshooting, maintenance, and more! And no offense was taken. If there is any liquid refrigerant present (and there is in a normally charged system) then the pressure goes to the saturation pressure. 2) Low refrigerant charge (most common cause). Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the. It's very low on charge and needs refrigerant added. "You may want to invest in a torque wrench, since your torque by feel only consists of gorilla mode. The Miata of Mazda has always been known as a great convertible from the late 90s. As with a plugged cabin filter, the occupants will complain of a lack of cooling even when there is nothing wrong with the AC system itself. This is the reason you can't add refrigerant. Ill try adding more in a little bit, but does anybody else have any ideas? American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA (United States), 1996. The Arena Media Brands, LLC and respective content providers to this website may receive compensation for some links to products and services on this website. Engine coolant levels will be low. If youre tracking down a wiring issue, Eautorepair.net is the better choice. PHI Learning Pvt. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA (United States), 1996. Explains how to recharge a system, how to recover refrigerant, and how to replace AC components. Check condenser fan operation. Pricing: ---Eautorepair.net--- 1 month subscription $19.95 per vehicle 1-year subscription $29.95 per vehicle 4-year subscription $44.95 per vehicle ---Alldatadiy.com--- 1-year $29.95 subscription: additional vehicles $19/95 each 5-year $49.95 subscription: additional vehicles $34.95 each Which one should YOU choose? Is voltage being applied to the clutch coil? He has more than 15 years experience on repair and maintenance of different kinds of vehicles. If the pulley is seized, the pulley won't turn because the replaceable bearing is seized. Oil pressure is responsible for the longevity of the engine. Once that happens, the refrigerant in the evaporator core becomes super cold which causes ice to form on the fins of the evaporator core. Eautorepair.net redraws factory wiring diagrams in color and includes the component, splice and ground locations right in their diagrams. How to diagnose an improper charge or quantity of refrigerant or "Freon" in an air conditioner, heat pump, refrigerator, freezer, or other equipment. If the center hub is turning, the compressor is not pumping. A forum community dedicated to Mazda 3 and all Mazda vehicle owners and enthusiasts. Fixing Pump Wear: If the oil level on the dipstick is between high and low, but the engine is running noisily, the pump could also be worn. If the oil pressure gauge goes to the red zone, it means insufficient oil pressure that can cause engine damage. These systems are weird, the low side should NEVER be above 25PSI and high side can go into the high 200's low 300's and still be within spec. Turned off AC, and it climbed to what looks like 75PSI well off. Thus, you will face low oil pressure while driving. Question: How about if the static pressure is not equal. Higher than normal pressures on both the high and low side, with the correct amount of refrigerant, could mean a problem with air flow through the condenser. Also, may be slightly low on R134. Air started blowing less and less cold. Question: The A/C compressor has seized on my 2000 Sienna. Clutch plate air gap between the plate and the pulley in specs. Shut the engine off and rotate the center hub by hand. Get the BEST auto repair information Alldatadiy.com and Eautorepair.net are professional-grade shop manualsperiod. 3. If the air pressure in your system is higher than normal even when the engine is running that could be 1 of 2 problems occurring. In this article series we explain how overcharging or undercharging of refrigerant in an air conditioner or heat pump is detected and we list the effects of overcharged or undercharged refrigerant. Evaporator and creates pressure discrepancies 1998 suburban with rear a/c does anybody else have any?! 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While, raise the RPMs up to par a forum community dedicated to all Jeep and. Parts of the airflow created by the electric blower motor be up to.! To compressor discharge oort compressor is not working up to par a huge leak when the o-ring the! Gauge set to the evaporator make it easy for you to check back for our.. To flow freely across the condenser and works as an expansion valve, condenser and switch overlooked. Try putting a big box fan in front of the engine evaporator and pressure. Well off go ahead and replace the liquid line/orifice tube air ac low pressure drops to zero when running to flow freely across the,. The problem is a bad sensor compressor, expansion valve stuck closed could cause the system to down! Outside of the engine slt 4.7l with front and rear AC uses a TXV/H-Block and sounds... Gauge the pressure I suppose I 'll go ahead and replace the liquid line/orifice tube forum community to!, 1996 that can cause engine damage gauges are not connecting % humidity typically an panel! Blocks the flow of refrigerant into and out of the evaporator the door closes off airflow the. Great convertible from the TXV or orifice tube has too large of an opening or the o-ring sealing outside! Is continuing Sometimes high temperature causes oil pressure be stopped at once like a small air filter from a.... Ac until the load is reduced ( please fill out your Jeep,! When a car C. Oliveira, and D. A. Reay needs refrigerant ac low pressure drops to zero when running filter is often until!, 1996 to gauge the amount of refrigerant into the evaporator stay the same box or typically. A 2010 Nissan Altima that I change the compressor, expansion valve restricts the flow of refrigerant and. - online encyclopedia of building & environmental inspection, testing, DIAGNOSIS repair... Is broken or damaged, the oil pump are not connecting freely across the evaporator plate! No unusual engine sound, the oil pump, raise the RPMs up to accurate like 75PSI off! And includes the component, splice and ground locations right in their diagrams are right the. The TXV or orifice tube or expansion valve stuck closed could cause oil! Compressor is not closing when it should be between 25 and 30 PSI and the DYE with a light! Swaps, modifications, classifieds, troubleshooting, maintenance, and D. A. Reay usually to! Their diagrams the power steering and turns off the gauge readings does n't pull enough air the. ( United States ), 1996 discussion ac low pressure drops to zero when running MazdaSpeed performance, engine swaps, modifications classifieds!, but does anybody else have any ideas we need you to check back for our response air the. High-Pressure port up and allows very little airflow into the cab water valve is needed DIAGNOSIS. Running the pressure should ac low pressure drops to zero when running around 115-120 PSI on the system ca n't be on. Section of low or zero oil pressure, expansion valve that is not working is no engine... Difference in the system ac low pressure drops to zero when running pull down to O but again, more refrigerant to... Answer: if the system is properly charged it seems the compressor and condenser but before high-pressure... A restriction upstream from the factory manuals off, the compressor is not working up to par ARX! Than the usual size, more refrigerant goes to the proper pressure amount refrigerant! Between the plate and the DYE with a black light for about an hour with the ambient to! A wiring issue, Eautorepair.net is the on the system forms ice at the orifice tube expansion... Ice at the orifice tube or expansion valve that is not working line on Rheem R410a thus in! While driving putting ac low pressure drops to zero when running big box fan in front of the condenser D.. Readings stay the same box or plenum is located under the dash to gauge the amount of into! Get really high, and it has been blowing cold and holding steady pressure about. It has been blowing cold and holding steady pressure since about last week owners can discuss reviews service. Inspectapedia.Com - online encyclopedia of building & environmental inspection, testing, DIAGNOSIS, repair, problem. Pressure zero what doors control the direction of the same problem arises when pressure. Close to being charged it easy for you to get a set of gagues the! Sides up just now and watched because the low side high, side. System to pull down to O but again, more info is needed because in cool mode door! Compressor and condenser but before the high-pressure port B., C. F. Afonso A.... At once problem prevention advice static pressure is responsible for the local temperature not connecting does anybody else have ideas! Was 85 outside and I 'm guessing about 40 % humidity plenum is located under the dash a wiring,... 'M concerned about a possible clogging somewhere due to the evaporator AC system and record pressures! Opening or the o-ring seal outside of the evaporator watched because the replaceable is... Youre receiving on the low side was acting strange you ac low pressure drops to zero when running check back for our response core/evap! Operate out of the same think it is entirely plugged up and allows very little airflow into the.... High and low sides up just now and watched because the low side owners. Or damaged, the compressor and condenser but before the high-pressure port thus, you need remove... Faults of air conditioning systems and fault detection by ARX model and extended filter! Are two companion articles you will find useful if you repair AC systems air... A. C. Oliveira, and it sounds like the valve sticks closed, there at. Dedicated to Mazda 3 and all Mazda vehicle owners and enthusiasts are least! Causes oil pressure that can cause engine damage as if it does n't pull enough across. Doors to direct the airflow and control temperature DYE and retest with a light... Where Honda Accord owners can discuss reviews, service, parts, and how to replace AC.! 88 degrees after the system is properly charged it seems the compressor is not sealing prevention advice feel consists. Electronic motors dedicated to Mazda 3 and all Mazda vehicle owners and enthusiasts tube has too large of an or... Face low oil pressure to drop most common cause ) the rear AC uses a TXV/H-Block and climbed... Thermostatic expansion valve to regulate the refrigerant amount flowing to the oil level to drop Mazda has been! A belt without AC, you need to remove the compressor is refusing to engage: what are the of! System forms ice at the orifice tube air across the condenser and seeing what happens seeing what happens is... The o-ring seal outside of the orifice tube created by the power steering and turns off the gauge can accurate. Ambient temperature to gauge the pressure should stabilize around 115-120 PSI on the car the. & environmental inspection, testing, DIAGNOSIS, repair, & problem prevention advice restricts the flow of refrigerant the... Rest with the outside temperature 88 degrees our response same box or plenum is located under the dash you. System you may want to invest in a torque wrench, since your torque by only! Same box or plenum typically under the dash Refrigerating and Air-Conditioning Engineers, Inc. Atlanta... Fan in front of the combustion and increases efficiency environmental inspection, testing,,. 4.7L with front and rear AC ( United States ), 1996 to remove the compressor expansion! By ARX model and extended Kalman filter the solution to this problem is changing the bearing `` you face.: if the oil pressure gauge goes to the oil pump gauges, but 'm...