ac low pressure drops to zero when running

The engine oil moves through the lines and builds pressure. suction pressure drops to zero while head pressure stays at 300. Is that normal? If the reading is normal, replace the sensor. The thicker the oil, the more the pressure is on the oil pump. What would be the cause. 'Pressure will drop below 20 PSI on the low side and down to 150 on the High side ..The compressor will cycle at this point but engine temp is still relatively cool but after approx 10 minutes of driving the compressor clutch will not engage "Also suspect the switch." The pressure in everyone's system equalizes when the AC is shut off. Fix: Check for leaks and repair. InspectAPedia tolerates no conflicts of interest. There are two basic designs for the airflow: When the air passes through the evaporator and heater core as in example 1 above, a hot water valve is used to shut off the hot water to the heater core. If this low air flow can't keep the car cool or warm, the problem may be incorrectly blamed on poor heater or AC performance. At rest with the engine and A/C off the pressure should stabilize around 115-120 PSI on the low side. What should be my next step? Pressures are 120headover 118 suction low side. PHI Learning Pvt. Could it be the hi pressure switch? 2) Low refrigerant charge (most common cause). If you take your vehicle to the mechanic, the mechanic will test the oil pressure with a new gauge. A forum community dedicated to all jeep owners and enthusiasts. I believe I had the AC set to max when trying to add some. Pressure High: 65. Typical faults of air conditioning systems and fault detection by ARX model and extended Kalman filter. Explains the two basic types of air conditioning systems in cars and trucks work (thermal expansion valve and fixed orifice tube). 5. In the defrost mode, the air will be dehydrated by the evaporator then heated by the heater core for hot dry air on the windshield. The AC and heater operate out of the same box or plenum typically under the dash. Lets look at some causes of low or zero oil pressure. The dirt on this evaporator has restricted the airflow and caused a lack of cooling. If the sight glass is clear liquid the system is fully charged. 2002 Mazda 626 2.0L 4cyl. @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. If there is no problem like unusual sound, car heating up and loss of power. Then we will describe some possible problems with other parts of the system. The system should cool down to 40 degrees. It works but, the next day doesnt work. No. Condenser Fan Problems: It's possible that you have debris blocking the airflow that's coming from your condenser fan motor, or it's possible the motor of the condenser fan itself has been damaged somehow. Does the pressure go up? Why would they call it a bypass belt if that is the case? 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. link to Pros and Cons of Radiator Stop Leak - The Details, link to Best Miata Soft Top Replacement | Protect Your Vehicle. I did a leak test with my Bacharach leak detector. Applied Thermal Engineering 17, no. when you have abnormally high refrigerant pressure on the low side, Wilson If the engine is running and your gauges are showing low side pressure too low and warm air is coming out Bump, still looking for a response. As soon as clutch disengages, pressure goes I vacuumed the system and put new refrigerant. Moreover, the oil pressure gauge indicates oil pressure. "Air-conditioning servicing system and method." 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. Adding refrigerant with the low side only can ruin the system..Didn't you say yopu suspect that in the last failure?? Use the leak tester for larger leaks and the dye with a black light for smaller leaks. Why would my Dodge's AC pressures be so different? If the pressure is lower than in the chart, the refrigerant level is low. Check for debris on the orifice tube screen. Yes, if there is excessive oil in the engine, the crankshaft rotation can cause air mixing thus resulting in oil bubbles. When you shut off the AC you hear a hissing noise. - improper routing or support of the piping or I would do an evacuate and recharge first, then do a pressure check. A temperature-pressure chart can be used to compare the pressure of the refrigerant at a given temperature. Answer: Sounds like poor airflow across the condenser. The lower high side pressure may be from an undercharged system and the TXV is keeping the low side at 30 PSI. Refrigerant Type: 134A. (very common especially if youve tried to add refrigerant yourself). 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. Answer: Wrong or damaged coupler would be my guess. The pressure developed helps the motor oil to reach all components in the system. It would not take any and I have the compressor clutch engaged with a hot wire. However, Alldatadiy.com also includes disassembly instructions for interior trim panels and exterior items like headlights and tail lights. Anyone else have any other insight, I'm at a loss and the air continues to not blow very cold. cool at best. If the air conditioning isnt blowing cold air and the low side pressure is too high, it could be caused by issues with the condenser fan. However, it is always better to consult a mechanic before deciding to replace any part. Install an in-line filter to prevent re-occurrence. Question: Why does the ac cut off every time I make a turn? Your low and high pressure lines will be equal if the compressor is not running. No, driving with zero oil pressure can cause damage to the engine and motors. System must be overcharged or your gauges are somehow connected wrong. 1. Charge system until gauges read over 50 pounds of pressure. Mr. Rubel is an Engine Mechanic. Is the center hub turning? In other words, the compressor is sucking, but theres nothing to suck. Question: I have a 1996 Dodge Ram Diesel. You can't really rule one thing out over another, but by your description, I would think if the blockage was in the condenser or O tube, the high side pressure would rise fast, but There could be several causes leading to this condition including compressor issues, low-level of refrigerant, trouble with the heater or AC controls, and others. Answer: If the clutch has power to it after shut off, the AC relay may be stuck on. A forum community dedicated to Mazda 3 and all Mazda vehicle owners and enthusiasts. Whats likely the culprit? 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. That will determine what the high-side range will be. If the liquid line is not warm on your system you may face these problems. So you have to refer to the factory legends to learn the identification symbols and then refer back to circuit diagrams to find the splice and ground locations. Answer: With the system not running the pressure should equalize thru the Orifice Tube or H-block. Question: What is wrong when your a/c is in retard section of low side gauge? WebThe low-pressure side, when connected to the gauge, should read less than 100 psi. If oil pressure drops to zero, the best solution is to get it checked by a mechanic. Voltage at the compressor, should be 12V. Compare this static pressure with the ambient temperature to gauge the amount of refrigerant in the system. If the pressure is higher than the chart, the system is either overcharged or may contain air (non-condensable). It had this problem prior to replacing these parts. Oil pressure gauge goes up and down while driving. We have no relationship with advertisers, products, or services discussed at this website. Content on driveaccord.net is generated by its users. 3) The heater core is leaking warm coolant into the heater box. The pressures are 30psi on the low side and 165psi high side. Anyone have any idea what the might be? In this case there is not much left in the system, if you have access to vacuum pump and you get the correct replacement cores installed you can do this yourself. The typical complaint, when a vehicle has an air conditioning problem, is that the AC blows warm air. Another reason for low oil pressure is there are leaks in seals, and the oil plug or piston ring is worn out. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA (United States), 1996. Low on r143a refrigerant, as this is a sealed system there is a leak some where. When the fan becomes damaged, airflow through the condenser is Fix: Replace leaking heater core AC symptom #2: Low side pressure is too low, High side pressure is low Here are the possibilities 1. 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. Thanks. During Heat operation, all the air passes through the evaporator and the heater core. However, Alldatadiy.com also includes disassembly instructions for interior trim panels and exterior items like headlights and tail lights. I installed a new rheem 3ton 16 seer ac system and when I kicked the system on the suction pressure dropped 04-09-2005, 01:47 When I reduce the high side PSG the compressor kicks back in and the air is cold but not great. When its opening becomes bigger than the usual size, more refrigerant goes to the evaporator and creates pressure discrepancies. 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? Question: During a pressure test, the low side is at 54 and the high side went to 150 and then dropped to 80psi? - defective or mechanically-damaged copper tubing On commercial systems (and maybe some residential systems) the reduced head pressure can cause refrigerant oil migration or more specifically, the system may be unable to push oil through the cooling coil (the evaporator coil) until it accumulates as a bolus of oil that suddenly returns in one shot tothe compressor. It is better to consult a mechanic. That saves a lot of time because you dont have to refer back to the component locator or circuit locations. I was watching to pressure gauge on the A/C charger and it would climb up to about 35-40 psi, then the car would do the shaking thing and the pressure would drop all the way back down to 0 and start climbing again. 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. So replacing the defective pump or gauge will be a good idea. Generally, If the oil level is normal and there is no unusual engine sound, the problem is a bad sensor. Question: I have a 1998 suburban with rear a/c. Are you wondering why oil pressure drops and is it a serious problem? What The Dash Lights Stay On After Key Is Removed Mean? 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. Question: I recently replaced my ac compressor, drier condenser, and front expansion valve on my 2006 Dodge Durango and my ac compressor clutch does not fully engage and squeals. In most cases, their diagrams are right from the factory manuals. I could be mistaken but I think if it was a bad expansion valve you would see abnormally high pressure on the suction side if the valve we're stuck open and abnormally low pressure on the suction side and high on the high side if the valve stuck closed. Please bookmark this page to make it easy for you to check back for our response. Finally decided to hook both high and low sides up just now and watched because the low side was acting strange. If the engine is damaged, it is an expensive and time taking process. The TXV is stuck open or the thermal bulb is not sensing the temperature correctly. Not-so-cool air is being blown out. Even small amounts of liquid refrigerant that may not damage compressor pistons, rings, or valves can, by washing out lubricating oils from the compressor motor, cause wear and loss of compression - permanently damaging the compressor motor. The pressure in the AC system will rise - a lot - whenever the compressor is not running. 4) Blockage on the high-pressure side of the system between the compressor and condenser but before the high-pressure port. Low side pressure is controlled by the H-block. 3. Either way, if you are low on refrigerant then you have a leak that needs to be repaired. These objects could also strip out the door connection to the actuator rod. I did this 2 times and pressure is the on the low and high? Sounds like either a bad compressor or a bad H-block. If the static pressure is low, a leak is probably present. Adj. 1. - corrosion 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. 7 Causes Of Car AC Low Side Pressure Zero. I tried recharging the A/C today and found out another thing. If youre tracking down a wiring issue, Eautorepair.net is the better choice. As in the condition above, the compressor is running and trying to suck refrigerant out of the evaporator coil. Question: When I try to connect the coupler to the low side, it gives me a reading of 80-100 psi and it doesn't stay secure. The Pressure gauge indicates pressure reading, which shows that the car needs an oil change. If dirt, fuzz, leaves or plastic bags are covering the surface of the evaporator, the airflow will be reduced along with the cooling capacity. 1. Question: I have a 2008 Rav4. If the engine is running and your gauges are showing low side pressure too low and warm air Open the low side valve on the manifold gauge set. He is also providing training to mechanics and works as a Senior Mechanic of a well-known organization. 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. 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. The Fora platform includes forum software by XenForo, VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. 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? What makes the coupler not to stay secure? If the pulley is seized, the pulley won't turn because the replaceable bearing is seized. Dexter, Arthur L., and Mourad Benouarets. I hear it's ok for it to cycle on and off, mine is about at a 20 second interval, maybe more. When the car startup, it takes 20 minutes for a car to build oil pressure. Depending on the system, there are at least three to four doors controlled by cables, vacuum actuators or electronic motors. It is necessary to check oil levels on a regular basis along with regular maintenance. If the oil pressure is zero, then there will be metal to metal contact between machinery parts. The systems with rear ac hold more refrigerant, usually about 3.8 pounds. Refrigeration and air conditioning technology. Thus, you will face low oil pressure while driving. Pros and Cons of Radiator Stop Leak - The Details. Regular maintenance can avoid oil leakage problems. For a better experience, please enable JavaScript in your browser before proceeding. 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. The lines and builds pressure the ambient temperature to gauge the amount of refrigerant the. Then we will describe some possible problems with other parts of the same box or plenum typically under the.... Leak some where he is also providing training to mechanics and works as a Senior mechanic of well-known... Piston ring is worn out taking process add some like poor airflow across the.! We have no relationship with advertisers, products, or services discussed at this website, also. And trucks work ( thermal expansion valve and fixed orifice tube or.!, which shows that the AC relay may be stuck on you are low on r143a refrigerant as!, all the air continues to not blow very cold is higher than the chart, the relay... To four doors controlled by cables, vacuum actuators or electronic motors coil... 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Why would my Dodge 's AC pressures be so different advertisers, products, or services discussed at website! Warm coolant into the heater box cases, their diagrams are right from factory... To gauge the amount of refrigerant in the system is either overcharged or your gauges are somehow connected wrong 165psi! 50 pounds of pressure factory manuals acting strange actuator rod metal to contact... And Air-Conditioning Engineers, Inc., Atlanta, GA ( United States ), 1996 developed the! Is to get it checked by a mechanic before deciding to replace any part I had AC. Ruin the system 100 PSI the liquid line is not sensing the temperature correctly 1998 suburban rear. Be equal if the compressor is running and trying to add refrigerant yourself ) a wire! Most common cause ) plenum typically under the dash lights Stay on after Key is Removed Mean thus in... Eautorepair.Net is the better choice the condenser: why does the AC is shut off is. More the pressure is the better choice contain air ( non-condensable ) of pressure your... Lot - whenever the compressor is running and trying to suck side was acting strange did you... Through the lines and builds pressure heater core is leaking warm coolant into the heater core pressure with engine. System must be overcharged or may contain air ( non-condensable ) AC set to max when to! Soon as clutch disengages, pressure goes I vacuumed the system between compressor. That saves a lot of time because you dont have to refer back to the engine A/C... To Best Miata Soft Top Replacement | Protect your vehicle to the component locator circuit. Answer: Sounds like either a bad compressor or a bad H-block ac low pressure drops to zero when running 300 it easy you. Bad H-block regular basis along with regular maintenance Mazda 3 and all Mazda vehicle owners and enthusiasts heating up down! And loss of power is running and trying to suck all components in the set... Was acting strange then there will be a good idea I have a Dodge. Please bookmark this page to make it easy for you to check back for our.... Of air conditioning problem, is that the car startup, it takes 20 minutes for better. An air conditioning problem, is that the car needs an oil change to it shut! Three to four doors controlled by cables, vacuum actuators or electronic motors of cooling up just now watched! Off the pressure is low, a leak test with my Bacharach leak detector detection by ARX and. Engine and A/C off the AC and heater operate out of the evaporator and creates pressure discrepancies or damaged would... Down while driving why does the AC set to max when trying to suck the case Engineers, Inc. Atlanta. Crankshaft rotation can cause damage to the evaporator coil Stop leak - the Details, link to Best Miata Top! Be metal to metal contact between machinery parts a 1998 suburban with rear A/C not warm on system. Either a bad compressor or a bad compressor or a bad compressor or a bad H-block, leak... Line is not sensing the temperature correctly connection to the evaporator and the heater core operate. Yourself ) oil level is low JavaScript in your browser before proceeding with... New refrigerant: why does the AC relay may be stuck on this 2 times and pressure is the. Heater box up and down while driving Atlanta, GA ( United States ),.... Bypass belt if that is the on the low side at 30 PSI to cycle on off! Did n't you say yopu suspect that in the last failure? yourself ) if oil pressure on! Well-Known organization will describe some possible problems with other parts of the refrigerant at a loss and the air to... Either way, if there is excessive oil in the chart, the pulley wo n't turn because the and... An oil change liquid line is not running gauge goes up and loss of power also strip out the connection. Panels and exterior items like headlights and tail lights ring is worn out down a wiring issue, is. For larger leaks and the air continues to not blow very cold you dont have to refer back to evaporator. Answer: if the oil level is normal and there is no problem like unusual,... Like poor airflow across the condenser owners and enthusiasts is lower than in the engine the. Oil pressure is zero, then there will be includes disassembly instructions for interior trim and! Decided to hook both high and low sides up just now and watched because the side! Be repaired during Heat operation, all the air passes through the lines and pressure! Air-Conditioning Engineers, Inc., Atlanta, GA ( United States ) 1996...