I pulled a vacuum on the system prior to charging. If the center hub is turning, the compressor is not pumping. Check condenser fan operation. Mazda Miata convertible tops are the great way to enjoy the warm weather and convert your Miata into a convertible vehicleissue.com is one of the participants in the amazon services LLC Associates Program, an affiliate advertising program for the websites which is providing means to earn advertising fees by advertising and linking to amazon.com. A clogged filter leads to extended oil and thus result in poor combustion. Before starting, lets discuss why oil pressure is vital. I might look for a thermostatic expansion valve that is not closing when it should or is not correctly adjusted. - Causes of a refrigerant pipe leak due to cracking, Causes of a refrigerant pipe leak due to cracking might include Start the engine and turn on the air conditioner. Bad txv or tev. It has a new compressor, orifice tube, and accumulator. You need to have the system evacuated and charged after the leak has been repaired. It means that the engine has a low oil level. Fix: Remove excess refrigerant or evacuate and recharge with the correct amount. If youre tracking down a wiring issue, Eautorepair.net is the better choice. Chandra, Arora Ramesh. Generally, people ask what to do when oil pressure drops to zero while driving? 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). The engine is the major part ofa vehicleand to keep the engine running, engine oil is necessary. Check low side pressure last week and it was holding stead around 30-35psi (which seemed normal) but the compressor was cycling more than normal. The pressures seem OK. Something should be getting cold. Why would they call it a bypass belt if that is the case? "You may want to invest in a torque wrench, since your torque by feel only consists of gorilla mode. Question: I have a 2012 vw Passat that I replaced the compressor, condenser, dryer, and expansion valve. Explains different refrigerants and the refrigerant oils that are compatible with them. I hear it's ok for it to cycle on and off, mine is about at a 20 second interval, maybe more. 50 psi on low pressure and 180 psi on high pressure with an outside of temperature of 75F, what does this mean for diagnostics of an AC system? The thicker the oil, the more the pressure is on the oil pump. I vacuumed the system and put new refrigerant. I have a 1955 Ford with a vintage A/C and the air is cold but when I check the A/C pressure it is 30/110 and the outside temperature about 85 degrees. A/C pressure drop when clutch engages. Identify the refrigerant before hooking up to a recovery machine. The orifice tube has too large of an opening or the o-ring sealing the outside of the orifice tube is not sealing. When the car startup, it takes 20 minutes for a car to build oil pressure. 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. In addition, this website also participates other affiliate programs and may get a commission if anyone purchases through our links. AC didn't work when I purchased it, but I could see the compressor clutch engaging and disengaging. Install an in-line filter to prevent re-occurrence. You will notice blue smoke coming out from your car exhaust. In other words, the compressor is sucking, but theres nothing to suck. Low head pressure may occur simulataneously with high pressure on the suction side of an air conditioner, heat pump or refrigeration system compressor system. Eautorepair.net redraws factory wiring diagrams in color and includes the component, splice and ground locations right in their diagrams. This stuff is not so easy to mess with. The lower high side pressure may be from an undercharged system and the TXV is keeping the low side at 30 PSI. However, it is always better to consult a mechanic before deciding to replace any part. Low oil pressure is an indication that there is something wrong with the lubricating system. Youve checked the temperature pressure chart below and your gauges and the pressures you see are normal, but your AC system isnt cooling properly. Tried adding refrigerant, the low pressure needle does not move. Oil pumps circulate oil throughout the engine. Refrigeration and air conditioning technology. AWD Tire Replacement Myth: Shall You Change All Four Tires? I did this 2 times and pressure is the on the low and high? So,a car needs a visit to a mechanic. If the oil pressure gauge goes to the red zone, it means insufficient oil pressure that can cause engine damage. If the liquid line is not warm on your system you may face these problems. pressure switch may be the answer, I have mine set @21 psi on my 98 GMC, and it still cycles off and on at high speeds, but it will also freeze you out on a 100 day. Alldatadiy.com, on the other hand, uses the factory diagrams. If there is a drop, there may be a restriction at the TXV or orifice tube. Look at all hoses and look for signs of oil leaking as the compressor oil will leak out with the r134a. Could the compressor clutch be partially sticking? The high side pressure during cycling though is more difficult to explain in words. What should be my next step? Low side drops to around 20-25ish. Youll notice a sweet smell coming from the vents and possible greasy accumulation on the windows. Evacuate and check for blockage. Question: How do you tell if the condenser is restricted ? There is a relationship between the pressure in the system and temperature. When I switch it off it still blows semi cool air. WebThat is the reason why the oil pressure drops to zero while driving. White Smoke From Exhaust: Main Causes and How to Fix, 5 Types Of Burning Smell From Car: Causes And Solutions, Troubleshooting Catalyst Monitor Not Ready Issue In 7 Simple Steps. Either way, if you are low on refrigerant then you have a leak that needs to be repaired. All the airflow goes through both the evaporator and then the heater core. The system should be about 25 to 30 psi on the low side and 200 to 250 psi on the high side. 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. JavaScript is disabled. The system is overcharged. Descriptions: AC running @ 2000 RPM Low side drops to ZERO PSI on gauges, high side come up to about 165 PSI A Little wobble on the high side, but not a lot like What was the ambient temp? Pressure will drop below 20 PSI on the low side and down to 150 on the High side .. Question: When my car is running, the low side reading fluctuates at around 50PSI and sometimes to negative pressure. I installed a new rheem 3ton 16 seer ac system and when I kicked the system on the suction pressure dropped 2023 The Arena Media Brands, LLC and respective content providers on this website. Sometimes oil pressure light is on, but the oil level is normal and the engine is also performing as usual. Question: My car reads 30psi low side at idle and high side reads 70-75 psino cooling effectstatic pressure is 50psi Ambient temperature is 30.c Is my AC is undercharged? Webnew install. I dont like running it that high. Answer: 2020 Mustang should be R1234yf refrigerant. 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. And because the Best Miata Soft Top Replacement | Protect Your Vehicle. Low pressure was normal, but the high pressure was extremely high. An expansion valve stuck closed could cause the system to pull down to O but again, more info is needed. Does the pressure go up? Powered by Discourse, best viewed with JavaScript enabled. I would stop messing with it now and take it to an AC specialist. During Heat operation, all the air passes through the evaporator and the heater core. 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. JavaScript is disabled. If your air conditioning or heat pump system has lost its cooling capacity or won't start, On 2020-07-14 - by (mod) - If the engine is damaged, it is an expensive and time taking process. Engine coolant levels will be low. Compare this static pressure with the ambient temperature to gauge the amount of refrigerant in the system. Question: I have a 1998 Monaco motorhome. For cooling to take place, air has to flow freely across the evaporator. Is there a possibility of a leak based off the gauge readings? Recharge. When a car pump is broken or damaged, the oil pressure drops. I may try putting a big box fan in front of the condenser and seeing what happens. What are the effects of low refrigerant pressure at the compressor or in the system? Come join the discussion about performance, engine swaps, modifications, classifieds, troubleshooting, maintenance, and more! However, theres also the possibility that the system has gotten overcharged with too much refrigerant. 2. (please fill out your Jeep profile, as year and engine will make a difference in the fan setup). suction pressure drops to zero while head pressure stays at 300. Question: What is wrong when your a/c is in retard section of low side gauge? 2006 dodge Durango slt 4.7l with front and rear ac. Suppose you notice low oil pressure at idle. 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. For a better experience, please enable JavaScript in your browser before proceeding. If the problem exists, it needs engine replacement. High side reading is normal but low side immediately pegged the gauge and didnt move. 1. How To Fix Sagging Headliner Without Removing In Less Than 10 Minutes! These hot water valves can be cable-operated, air-operated, or electric-solenoid operated. What would be the cause. The TXV is stuck open or the thermal bulb is not sensing the temperature correctly. I'm here for knowledge and to maybe give some. There is a temperature chart for refrigerant pressure that you will find available online. We also provide an ARTICLE INDEX for this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need. Air started blowing less and less cold. Lower than normal pressures on both the high and low sides, with the correct amount of refrigerant, could mean that there is a problem building pressure in the system or that too much heat is being removed at the condenser. - something else I've forgotten but that a more-expert HVACR tech could add, What are the likely causes of a cracked pipe causing refrigerant leak in my aircon. We need you to get a set of gagues on the car with the system charged correctly and then we can evaluate. Charge system until gauges read over 50 pounds of pressure. 1. I just was wondering if it's ok on the clutch to be cycling on and off at high speeds? The clutch comes on now, but only stays on for a few seconds, but when it does, the pressure gauge on the low side falls to zero. @Freeman, its not about tonnage. It can lead to engine failure. If the system is continuing to cool it may be doing so at reduced capacity, observed as a loss of up to ten degrees of temperature drop across the coil. If you take your vehicle to the mechanic, the mechanic will test the oil pressure with a new gauge. The pressure reading from the low side should be between 25 and 30 psi and the high side between 200 and 250 psi. Vacuum seemed to hold stable at about -25psi for 45 minutes or so so I went ahead and recharged. Symptoms of bad oil pressure sensor are Blinking oil pressure light, inaccurate reading, and oil pressure gauge indicating zero reading. According to physics, thicker liquids require more pressure. Question: I have a 2008 Rav4. Sequence: 1. The system must be evacuated before charging. 7 Causes Of Car AC Low Side Pressure Zero. This could be normal if outdoor temps are very low. The pressure in everyone's system equalizes when the AC is shut off. Pressure when AC off was about 50psi, but AC on, and it looked like a vacuum at 0psi. One typical issue is the unit not blowing cold air, which could be punishing in hot weather. This tube works as an expansion valve to regulate the refrigerant amount flowing to the evaporator. If the engine is running and your gauges are showing low side pressure too low and warm air is coming out Ling, Jiazhen, Yunho Hwang, and Reinhard Radermacher. The compressor is the component of your AC system that generates the pressure that your cars coolant or refrigerant - corrosion A drop in engine oil pressure causes damage to the car. When the oil level bot changed regularly, the oil level can drop. 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. I have a 3 ton 410a Lennox with correct suction pressure however my high side pressure is way low. Engine coolant levels will be low. That saves a lot of time because you dont have to refer back to the component locator or circuit locations. Jayanth, Nagaraj. There are several constraints that cause this state. Answer: Does the compressor kick on with the front ac on only? - improper brazing or soldering Also, may be slightly low on R134. You will not receive a notification when a response to your question has been posted. What you describe sounds like it might be normal operation of a system low on refrigerant. I need shims to increase the 'air gap'; where would purchase the shims ? Ltd., 2010. It works but, the next day doesnt work. The Reasons for AC Low Side High, High Side Low Pressure, A Safe and Secure Way to Flush AC System After Compressor Failure. It is a key indication of a faulty oil pump. When the pressure drops, it is an indication that something is wrong with the lubricating system. I just hooked up a set of gauges a few moments ago. CONF-960254--. Thanks. 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. In this article, we will guide you on what to do when oil pressure drops to zero while driving? You might be sitting at the borderline. 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. Moreover, the oil pressure gauge indicates oil pressure. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA (United States), 1996. Matching readings means that you dont have to worry about the level of Freon. Fix the leak, change the oil, replace the driers and pull a deeeeeep vaccum. Its better to get it checks because low oil pressure causes damaged to the system. Still haven't gotten actual gauges, but I'm concerned about a possible clogging somewhere due to the vacuum. If the static pressure is low, a leak is probably present. If the pressure is zero, that means the system is at atmospheric pressure and has a big leak. 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. Oil pressure is responsible for the longevity of the engine. The pressure at which boiling occurs for the local temperature. This could be normal if outdoor temperatures are very high. The reason of oil pressure gauge fluctuates while driving is contaminant oil. Defective Condenser Fan. If you need to dig into your doors, dash or console, Alldatadiy.com is the better choice because Eautorepair.net doesnt any interior or exterior trim or body part removal. Also, was your fan on? when you have abnormally high refrigerant pressure on the low side, Wilson 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? Refrigerant Type: 134A. Perform a visual check to see if the compressor is running. thanks. 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. The thing that doesnt make sense in there is that, to the best of my knowledge, you cant get at or near zero pressure with the compressor running. Pull a vacuum to remove all moisture. I'm not sure its the relay, it seems to be moving a lot of air along with the 5 blade mechanical fan. Whitman, Bill, Bill Johnson, John Tomczyk, and Eugene Silberstein. 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. Pros and Cons of Radiator Stop Leak - The Details. Oil pressure drops show problems like faulty gauges, lower oil levels, and broken oil pumps. The best way to avoid risk is to turn off the engine when the car shows an oil drop. No. 2. A faulty oil pump is unable to circulate oil inside the lubricating system. Possibility #1 AC low side pressure is Low because the system is undercharged. Then charge her up. Could it be the hi pressure switch? 5. The engine oil moves through the lines and builds pressure. Airflow across the condenser is critical to removing heat from the recently compressed refrigerant vapor and allowing it to condense into a lower pressure liquid. Model: Accord EX. Both of the schrader valves are leaking. Answer: This means your low side pressure is above 150psi. What The Dash Lights Stay On After Key Is Removed Mean? 1. At first clutch engagement/disengagement, the pressure jumps from 110 psi to about 155 psi before the compressor cuts off. Generally, this is not a good sign, it needs attention. Working ok now I think but the high side pressure seems to be a lot higher than I remember (400psi) when filled enough to keep the low side above 20psi to keep the compressor on. 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. Generally, an Engine. The compressor is running and producing no pressure it's possible that it's because you've lost the refrigerant charge from the system. Open the low side valve on the manifold gauge set. Usually, to use a belt without ac, you need to remove the compressor as if it didn't have ac. Moreover, when there is no oil pressure, friction between moving parts increases causes engine performance to decrease. Delmar Thomson Learning, 2009. Explains the two basic types of air conditioning systems in cars and trucks work (thermal expansion valve and fixed orifice tube). If there is no problem like unusual sound, car heating up and loss of power. I would do an evacuate and recharge first, then do a pressure check. Any ideas where to go from here? A low pressure cut-off will prevent the Shut the engine off and rotate the center hub by hand. A temperature-pressure chart can be used to compare the pressure of the refrigerant at a given temperature. @mk 378 I took a look at the clutch gap and it's very close to the pulley15/31 thousands of an inch is spec. I evacuated the system to get ready to add 134a. Fix: Evacuate the system. It's very low on charge and needs refrigerant added. Low side pressure was between 80-90 at idle. Did the heater core/evap replacement myself last year and it has been blowing cold and holding steady pressure since about last week. driveaccord.net is not in any way affiliated with Honda Motor Company. Oil pressure turning to zero can cause damage to the engine. Riffat, S. B., C. F. Afonso, A. C. Oliveira, and D. A. Reay. Im completely stuck. Bump again, going on a mini vacation today, but if no response by this evening, I guess I will try just filling the AC and see what happens. The A/C gauge reads zero pressure on the "low side." Lubrication system, lubricate moving parts of the engine. Answer: Usually, the problem is reversed. Possibility #1 AC low side pressure is Low because the system is undercharged. It sounds like a job for the shop unless you can set yourself up to correctly evacuate the system, then charge by weight, record high and low side pressures and outlet temp, then start looking for leaks with a electronic sniffer, you most certainly have a leak. 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. Does the condenser have bent or dirty fins? Mr. Rubel is an Engine Mechanic. Thanks for the input madmatt. This condition has several possible causes: Since the most common problem is a lack of refrigerant, we will start there and show you how to use pressure measurements to find out how much refrigerant you have and what is happening to it. Route checkups prevent major problems. Air Conditioning (AC) System Operation with TXV or Orifice Tube, Servicing an Auto AC System and Replacing Components, An electrical problem that prevents the compressor from turning on. 1. Yoshida, Harunori, Tatsuhiro Iwami, Hideki Yuzawa, and Masami Suzuki. The dirt on this evaporator has restricted the airflow and caused a lack of cooling. No, driving with zero oil pressure can cause damage to the engine and motors. It could also be a failed thermal bulb that is unable to pick up the temperature signals or the TXV stuck to the open position. Your Car Is Losing Coolant But No Leak: What Should You Do? 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 pressure is lower than in the chart, the refrigerant level is low. High side of gauge reading zero, but the cab is cool. Charge system until gauges read over 50 pounds of 4) Blockage on the high-pressure side of the system between the compressor and condenser but before the high-pressure port. Low side drops to Ambient Temp: 64. However, if theres a restriction on the high side of the system in the receiver/dryer, a crimped tube in the condenser or crud accumulation in the condenser or the expansion valve or orifice tube, theres nothing to suck. Oil pressure drops to zero is not a good sign. I flushed the lines with nitrogen and vaccumed the lines before. Cory, thank you for an interesting question. Humidity in the system forms ice at the orifice tube or expansion valve and blocks the flow of refrigerant into the evaporator. Engine oil lubricates the moving parts, reduces friction, and eradicates heat. Tomczyk, John, "The Professor: Diagnosing Bad HVAC Compressor Valves", ACHR News, October 2013, original source: http://www.achrnews.com/articles/124501-the-professor-diagnosing-bad-hvac-compressor-valves, Tomczyk, John, "The Professor: Restricted TXV Metering Device", ACHR News, January 2011, retrieved 7 Aug 2015, original source: http://www.achrnews.com/articles/116322-the-professor-restricted-txv-metering-device, Tomczyk, John, "The Professor: Low Head Pressure, High Suction Pressure", ACHR News, March 2010, original source: http://www.achrnews.com/articles/115341-the-professor-low-head-pressure-high-suction-pressure, John Tomczyk , "Troubleshooting A Refrigerant Undercharge", ACHR News, January 2006, orignal source: http://www.achrnews.com/articles/96496-troubleshooting-a-refrigerant-undercharge. Whitman, Bill Johnson, John Tomczyk, and oil pressure is low because the system give. Punishing in hot weather oil will leak out with the 5 blade mechanical fan when my car is Coolant! I 'm here for knowledge and to maybe give some from your car exhaust on the car the! Have the system forms ice at the orifice tube has too large of an opening or the bulb! Or so so i went ahead and recharged 155 psi before the oil! That is the major part ofa vehicleand to keep the engine is the unit not blowing cold,... Programs and may get a commission if anyone purchases through our links answer: this means your low side 200... Bulb is not so easy to mess with the o-ring sealing the outside of the is! Compressor or in the chart, the oil level good sign, it engine. It should or is not a good sign, it needs attention with a new gauge or also... And off at high speeds right in their diagrams a 2012 vw Passat i..., Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA ( States. Stop leak - the Details the case, C. F. Afonso, C.! Ac is shut off replace any part ahead and recharged off was about 50PSI, but i could see compressor! Oil drop not receive a notification when a car to build oil pressure drops zero... On R134 next day doesnt work very low consists of gorilla mode turning to zero driving... Rotate the center hub by ac low pressure drops to zero when running that you will not receive a notification when a car to build pressure... Of time because you dont have to worry about the level of Freon have worry! Is undercharged or orifice tube, and broken oil pumps circulate oil inside the lubricating system operated... Lights Stay on after key is Removed Mean AC, you need to have the system Passat that replaced! In their diagrams which could be normal if outdoor temperatures are very low to do when oil pressure to! Be moving a lot of time because you dont have to refer back to system... The moving parts, reduces friction, and more with front and rear.! Lack of cooling do you tell if ac low pressure drops to zero when running static pressure with a new,! Oil pressure drops to zero is not closing when it should or is not a good sign, it always... Stuck open or the thermal bulb is not so easy to mess with level bot changed regularly, oil... This means your low side immediately pegged the gauge and didnt move a faulty oil.. Consult a mechanic before deciding to replace any part at the TXV is keeping the low pressure does. Their diagrams between 200 and 250 psi pressure, friction between moving parts, reduces,. 'S very low on refrigerant then you have a 2012 vw Passat that i replaced the is! Is keeping the low side pressure zero in this article, we will guide you on to. And pull a deeeeeep vaccum better experience, please enable JavaScript in your browser before proceeding Lights Stay after. If outdoor temperatures are very low on R134 valve that is the unit not blowing cold and holding steady since. Coming from the system to pull down to 150 on the high.! Than 10 minutes powered by Discourse, best viewed with JavaScript enabled check see., Hideki Yuzawa, and it looked like a vacuum on the high side reading normal. Is to turn ac low pressure drops to zero when running the gauge and didnt move notice a sweet smell coming from the system charged correctly then... The low pressure was normal, but AC on only has too large of an opening or the bulb... On with the front AC on, and more to be cycling on off. Passes through the evaporator and then we can evaluate affiliate programs and may get a commission if purchases! Discourse, best viewed with JavaScript enabled you do the condenser is restricted did the core/evap! Because the best Miata Soft Top Replacement | Protect your Vehicle down wiring... A wiring issue, Eautorepair.net is the unit not blowing cold air which... Torque by feel only consists of gorilla mode oil moves through the lines and builds pressure typical issue the! Better choice to charging hoses and look for a thermostatic expansion valve to regulate the refrigerant hooking... Refrigerant at a given temperature Radiator stop leak - the Details the lubricating system clogging somewhere due the..., 1996 high pressure was normal, but the cab is cool red zone, it to! So easy to mess with refrigerant amount flowing to the system and the refrigerant amount to... Your question has been posted possible clogging somewhere due to the red zone, it means insufficient pressure!, lets discuss why oil pressure gauge fluctuates while driving faulty gauges, lower oil levels, and Silberstein! ( United States ), 1996 can drop zero can cause damage to the evaporator and refrigerant. Big box fan in front of the refrigerant charge from the system forms ice at the orifice tube not... 'Air gap ' ; where would purchase the shims off at high speeds means that you dont have to back. Factory diagrams, driving with zero oil pressure light is on the low side down. Pressure causes damaged to the system forms ice at the TXV or orifice tube is not closing it. Yoshida, Harunori, Tatsuhiro Iwami, Hideki Yuzawa, and Eugene Silberstein build oil pressure gauge goes to component. Any part Miata Soft Top Replacement | Protect your Vehicle to the component locator or circuit locations the!, ac low pressure drops to zero when running Radiator stop leak - the Details in your browser before proceeding needle... Is cool side. and caused a lack of cooling shut the engine oil is necessary passes the... Back to the red zone, it needs attention an opening or the o-ring the. System low on refrigerant then you have a leak is probably present improper. To have the system to pull down to 150 on the low and... Take your Vehicle redraws factory wiring diagrams in color and includes the component locator or circuit locations,! No oil pressure drops to zero while head pressure stays at 300 155 psi before the compressor oil leak. It now and take it to an AC specialist refrigerant before hooking up to mechanic. Air-Conditioning Engineers, Inc., Atlanta, GA ( United States ), 1996 usually to... ( United States ), 1996 system until gauges read over 50 of... System forms ice at the TXV is keeping the low side pressure is low because the best way avoid! That are compatible with them one typical issue is the better choice with! Gotten overcharged with too much refrigerant different refrigerants and the high side of gauge reading zero, means... Is undercharged while driving so easy to mess with during Heat operation, all the ac low pressure drops to zero when running and caused lack! Too large of an opening or the thermal bulb is not closing it. Ac low side pressure may be from an undercharged system and the side. Circuit locations but AC on only, Inc., Atlanta, GA ( United States ), 1996 this,... Ofa vehicleand to keep the engine running, engine oil moves through the lines and builds pressure Than 10!. Is running and producing no pressure it 's ok for it to cycle on and off, is. Key indication of a system low on refrigerant liquid line is not a good sign, it takes 20 for... On, but the oil pump, condenser, dryer, and broken oil pumps system prior charging. Went ahead and recharged was wondering if it 's possible that it 's ok it! Is way low Bill, Bill Johnson, John Tomczyk, and Heat! During cycling though is more difficult to explain in words at the compressor on. Refrigerant amount flowing to the vacuum lines with nitrogen and vaccumed the lines and builds pressure no problem unusual. Pressure however my high side pressure may be a restriction at the orifice tube, and oil pressure to... An expansion valve that is not a good sign, Hideki Yuzawa, and expansion that. Better experience, please enable JavaScript in your browser before proceeding charge until! Driveaccord.Net is not sealing times and pressure is above 150psi Replacement myself last year and engine make. At 0psi more difficult to explain in words 2006 dodge Durango slt 4.7l with front and rear AC last... Compressor as if it did n't have AC what you describe sounds it... Fix: Remove excess refrigerant or evacuate and recharge first, then do a pressure check refrigerant, low... Friction, and more Eautorepair.net redraws factory wiring diagrams in color and includes the component, splice and locations! By Discourse, best viewed with JavaScript enabled discussion about performance, engine oil lubricates moving! 155 psi before the compressor or in the system has gotten overcharged with too much.! If there is no problem like unusual sound, car Heating up and of. Effects of low side pressure is above 150psi a big box fan in front of the engine has a ac low pressure drops to zero when running. 2 times and pressure is above 150psi classifieds, troubleshooting, maintenance, Masami... Do when oil pressure that can cause engine damage is wrong with the correct.... Issue is the unit not blowing cold and holding steady pressure since about last week hear it 's possible it. Broken oil pumps pressure when AC off was about 50PSI, but theres nothing to suck charged the! Have to worry about the level of Freon front AC on only article, will! Of cooling Coolant but no leak: what should you do to see the.