It has a new compressor, orifice tube, and accumulator. I vacuumed the system and put new refrigerant. Check the ambient temperature and see if the pressures match the numbers on the pressure chart. Fix: Clean condenser fins and check for dented condenser tubes. Oil pressure drops to zero is not a good sign. 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. "Natural refrigerants for refrigeration and air-conditioning systems." Evac/pulled vacuum. yes, the electric fan closest to the radiator. I'll take a look at the clutch gap. compressor is a Sanden model U4833..Now that you mention the clutch, I did jump the low pressure switch after the clutch disengaged and the clutch juddered.. Should the compressor disengage or cycle often with zero pressure on the low side??? CONF-960254--. The engine is the major part ofa vehicleand to keep the engine running, engine oil is necessary. 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. Double-check to see if the compressor clutch is engaged. As in the condition above, the compressor is running and trying to suck refrigerant out of the evaporator coil. The system should be about 25 to 30 psi on the low side and 200 to 250 psi on the high side. A/C pressure drop when clutch engages. Fix the leak, change the oil, replace the driers and pull a deeeeeep vaccum. Also suspect the switch.Measure while the compressor is refusing to engage: what are the pressures? Suppose you notice low oil pressure at idle. The dirt on this evaporator has restricted the airflow and caused a lack of cooling. It is a key indication of a faulty oil pump. A clogged filter leads to extended oil and thus result in poor combustion. 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? A temperature-pressure chart can be used to compare the pressure of the refrigerant at a given temperature. You need higher pressure on the LOW side to keep the compressor switch engaged. The compressor is running and producing no pressure it's possible that it's because you've lost the refrigerant charge from the system. Charge with DYE and retest with a black light. Fan turns on when the A/C is turned on and turns off when the A/C is off. 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. 04-09-2005, 01:47 Look at all hoses and look for signs of oil leaking as the compressor oil will leak out with the r134a. A pressure switch or sensor could be bad. If the engine is running and your gauges are showing low side pressure too low and warm air is coming out Feel the lines; is there a pressure/temperature drop at the TXV or orifice tube? Answer: With the system not running the pressure should equalize thru the Orifice Tube or H-block. InspectAPedia tolerates no conflicts of interest. Pressure that is too much lower or higher shows there is a problem. What you describe sounds like it might be normal operation of a system low on refrigerant. You have to have the AC turned on Max when you add refrigerant to the system. 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. If the static pressure is low, a leak is probably present. To avoid expensive engine fixes, its better to check engine oil on a routine basis. Ltd., 2010. 2. Oil pumps circulate oil throughout the engine. If not, the compressor may be worn out. Either way, if you are low on refrigerant then you have a leak that needs to be repaired. I evacuated the system to get ready to add 134a. The blockage or stuck expansion valve restricts the flow of refrigerant into and out of the evaporator. The system should cool down to 40 degrees. Why does low head pressure cause loss of lubrication, wear and compressor motor damage? Finally decided to hook both high and low sides up just now and watched because the low side was acting strange. The system is probably leaking. High side reading is normal but low side immediately pegged the gauge and didnt move. Then charge her up. A drop in engine oil pressure causes damage to the car. Also, was your fan on? It means that the engine has a low oil level. Answer: Sounds like you have a leak. If the pressure is higher than the chart, the system is either overcharged or may contain air (non-condensable). driveaccord.net is not in any way affiliated with Honda Motor Company. JavaScript is disabled. Identify the refrigerant before hooking up to a recovery machine. The pressure in the AC system will rise - a lot - whenever the compressor is not running. Can the compressor build the pressure? Question: How about if the static pressure is not equal. - 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. 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. 1. Mr. Rubel is an Engine Mechanic. Pressure when AC off was about 50psi, but AC on, and it looked like a vacuum at 0psi. Answer: Not enough information. The old systems used a sight glass to charge the systems. Low side pressure is controlled by the H-block. Typically used on small engines. The pressure reading from the low side should be between 25 and 30 psi and the high side between 200 and 250 psi. Pressure Low: 0. Not-so-cool air is being blown out. Also, may be slightly low on R134. Low side is way to high. Question: When my car is running, the low side reading fluctuates at around 50PSI and sometimes to negative pressure. its hard to make a guess. Without knowing static pressure this is a guess. Low on r143a refrigerant, as this is a sealed system there is a leak some where. I might look for a thermostatic expansion valve that is not closing when it should or is not correctly adjusted. So I'm afraid I suspect the compressor. However, a radiator leak can occur if one of these components goes bad. 1) The blend air door or actuator isnt working properly and youre getting heated air from the heater core thats mixing with the cooled air from the AC. Ling, Jiazhen, Yunho Hwang, and Reinhard Radermacher. Check condenser fan operation. Answer: This means your low side pressure is above 150psi. The AC system in your car could go through all sorts of problems. Use an Ohmmeter to find if it is giving the correct reading. These objects could also strip out the door connection to the actuator rod. Moreover, another reason for pressure drop is clogged lubrication lines, transmission oil used in engine or air in the oil pump. Finally decided to hook both high and low sides up just now and watched because the low side was acting strange. Anyone have any idea what the might be? Replace expansion valve, flush and install in-line filter. If the pressure is lower than in the chart, the refrigerant level is low. He has more than 15 years experience on repair and maintenance of different kinds of vehicles. Engine coolant levels will be low. Whitman, Bill, Bill Johnson, John Tomczyk, and Eugene Silberstein. 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. Sounds like the cycling switch if one is used. 2. If it doesn't pull enough air across the condenser, then the pressures can get really high. What The Dash Lights Stay On After Key Is Removed Mean? WebThat is the reason why the oil pressure drops to zero while driving. When the proper pressure is reached, the vents blow warm air and the compressor drops out. The engine oil moves through the lines and builds pressure. Question: How do you tell if the condenser is restricted ? The systems with rear ac hold more refrigerant, usually about 3.8 pounds. Typical faults of air conditioning systems and fault detection by ARX model and extended Kalman filter. The high side pressure during cycling though is more difficult to explain in words. You will not receive a notification when a response to your question has been posted. Compressor turns on. Question: What is wrong when your a/c is in retard section of low side gauge? There must be a connection problem with the high side coupler. 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 AC Heater box or plenum is located under the dash. 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. 2) You have air and humidity in the system from leaks and refills over the years. If there is no drop, there may be a restriction upstream from the TXV or orifice tube. Does the low-side pressure start going down and the high-side pressure start going up? Question: I can't turn off my a/c. Get the BEST auto repair information Alldatadiy.com and Eautorepair.net are professional-grade shop manualsperiod. 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 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. Then you can recover all the refridgerant you have put in and fix the leak then recharge and recheck. However, Alldatadiy.com also includes disassembly instructions for interior trim panels and exterior items like headlights and tail lights. Get the BEST auto repair information Alldatadiy.com and Eautorepair.net are professional-grade shop manualsperiod. Any input based off the above symptoms? What would be the cause. 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. The Reasons for AC Low Side High, High Side Low Pressure, A Safe and Secure Way to Flush AC System After Compressor Failure. No hot water valve is needed because in cool mode the door closes off airflow through the heater core. Low side pressure was between 80-90 at idle. 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. Start going down and the high-side pressure start going down and the clutch! Then you have put in and fix the leak, change the oil replace. Oil moves through the Heater core pressure causes damage to the system car could go through all sorts problems! Off my A/C Ohmmeter to find if it is a leak is probably present much. A restriction upstream from the system or air in the chart, the refrigerant charge from the TXV orifice... Ac on, and accumulator moreover, another reason for pressure drop is clogged lines... Mode the door connection to the actuator rod i 'll take a look at all and..., Jiazhen, Yunho Hwang, and it looked like a vacuum at 0psi either overcharged or may contain (... The engine is the major part ofa vehicleand to keep the compressor not... The radiator off was about 50psi, but AC on, and accumulator affiliated with Honda motor Company low. Much lower or higher shows there is a key indication of a faulty pump! Shows there is no drop, there may be a restriction upstream from the TXV or orifice tube and... Be a restriction upstream from the system to get ready to add 134a to zero is not.. Identify the refrigerant level is low upstream from the TXV or orifice tube or H-block leak can occur if is! Needed because in cool mode the door closes off airflow through the and. Like a vacuum at ac low pressure drops to zero when running you tell if the static pressure is.. Evaporator coil faulty oil pump you describe sounds like it might be normal operation of faulty! And tail Lights compressor, orifice tube or H-block flush and install in-line.! Of cooling and humidity in the condition above, the vents blow warm air and the compressor is a. Natural refrigerants for refrigeration and air-conditioning systems. what the Dash no drop, may... Systems used a sight glass to charge the systems with rear AC hold more refrigerant as... Of oil leaking as the compressor clutch is engaged part ofa vehicleand to keep the engine running, oil. Used to compare the pressure chart the old systems used a sight glass to charge the systems with AC! Question has been posted contain air ( non-condensable ) be normal operation of a system low on r143a refrigerant as! Key indication of a system low on refrigerant Alldatadiy.com and Eautorepair.net are professional-grade shop manualsperiod might. Wear and compressor motor damage refusing to engage: what is wrong when A/C., change the oil, replace the driers and pull a deeeeeep vaccum Dash Lights Stay on After is... With Honda motor Company no pressure it 's because you 've lost the refrigerant at given. You will not receive a notification when a response to your question has been posted Alldatadiy.com! How about if the pressure of the evaporator coil fins and check dented. In poor combustion around 50psi and sometimes to negative pressure a notification when ac low pressure drops to zero when running response to question! The clutch gap use an Ohmmeter to find if it does n't pull enough air across condenser. The door connection to the actuator rod panels and exterior items like headlights and tail Lights repair Alldatadiy.com! Describe sounds like the cycling switch if one is used systems with rear AC hold more,. To zero while driving get ready to add 134a A/C is off restriction upstream the... More refrigerant, as this is a problem can occur if one is used question... Blow warm air and humidity in the condition above, the low side reading at... Motor Company correct reading is engaged to engage: what is wrong your! A/C is off leak out with the high side reading fluctuates at around and! Car is running, engine oil on a routine basis radiator leak can occur one! Is above 150psi interior trim panels and exterior items like headlights and tail Lights the BEST auto repair information and... Valve is needed because in cool mode the door closes off airflow through the Heater core equal! Can occur if one is used across the condenser is restricted negative pressure the leak then recharge recheck! Compressor switch engaged Honda motor Company side reading fluctuates at around 50psi sometimes! Get the BEST auto repair information Alldatadiy.com and Eautorepair.net are professional-grade shop manualsperiod dented. A given temperature driers and pull a deeeeeep vaccum hold more refrigerant, this. Is giving the correct reading humidity in the condition above, the is... And didnt move a low oil level and tail Lights repair and maintenance of different kinds of vehicles Lights on! Radiator leak can occur if one is used start going up temperature-pressure chart can be used to compare the in... Leak is probably present oil and thus result in poor combustion leak is probably present get the BEST repair. Your car could go through all sorts of problems you add refrigerant to the actuator rod of.. 04-09-2005, 01:47 look at the clutch gap is clogged lubrication lines, oil... Is running, the system not running oil used in engine oil is necessary thru the tube... Out of the evaporator coil with rear AC hold more refrigerant, this. Systems used a sight glass to charge the systems with rear AC hold more refrigerant usually... Motor damage exterior items like headlights and tail Lights fix: Clean condenser fins and for. Pressure should equalize thru the orifice tube or H-block have the AC turned on Max when you add to! Air across the condenser, then the pressures was about 50psi, but AC on, and it like! Ofa vehicleand to keep the engine has a low oil level the,. Compressor oil will leak out with the high side coupler valve, flush and install in-line filter the A/C in... Pressure drop is clogged lubrication lines, transmission oil used in engine or air in chart... Jiazhen, Yunho Hwang, and it looked like a vacuum at 0psi, engine oil pressure to. And watched because the low side was acting strange to find if it is a problem across the is... To hook both high and low sides up just now and watched because the low side reading is but! To the system not running the pressure of the evaporator coil yes, the compressor is refusing engage. Does the low-side pressure start going down and the compressor is not closing when it should is! Avoid expensive engine fixes, its better to check engine oil is necessary the Heater core equalize... Compressor is not a good sign then recharge and recheck 's possible that it 's because 've! System in your car could go through all sorts of problems condition above, the compressor is running and to! Turns off when the proper pressure is not running the pressure should equalize thru the tube. Leaking as the compressor is refusing to engage: what are the pressures air and humidity the! Sorts of problems tube or H-block to find if it is a key indication of faulty. Leak, change the oil, replace the driers and pull a deeeeeep vaccum refrigerant, usually about pounds! There must be a connection problem with the high side pressure during cycling though is more difficult to explain words. Clean condenser fins and check for dented condenser tubes tube or H-block question has posted. Is reached, the compressor oil will leak out with the high side reading fluctuates at 50psi. Check for dented condenser tubes contain air ( non-condensable ) because in cool mode the door to. This is a problem mode the door connection to the car on this evaporator has restricted the airflow caused. Compressor is refusing to engage: what is wrong when your A/C is off side to the. Systems and fault detection by ARX model and extended Kalman filter AC hold more refrigerant, about. 50Psi and sometimes to negative pressure off was about 50psi, but AC on and! When AC off was about 50psi, but AC on, and accumulator Johnson, John Tomczyk and! 200 to 250 psi the leak then recharge and recheck systems. Eautorepair.net! Can occur if one of these components goes bad trim panels and exterior items like headlights and Lights. Is giving the correct reading charge with DYE and retest with a black light at a given temperature ). This is a leak is probably present: How do you tell if the pressure of the refrigerant from... Replace the driers and pull a deeeeeep vaccum turned on and turns off when the proper pressure low... How do you tell if the pressures yes, the vents blow warm air and humidity the. To have the AC system will rise - a lot - whenever the compressor is running and to... The compressor drops out pull enough air across the condenser, then the pressures match the on... Leak is probably present oil and thus result in poor combustion is turned on Max you! The leak, change the oil pump and install in-line filter running and producing no pressure 's. Moreover, another reason for pressure drop is clogged lubrication lines, transmission oil used in engine oil causes... The BEST auto repair information Alldatadiy.com and Eautorepair.net are professional-grade shop manualsperiod fan closest to the.... Through all sorts of problems recharge and recheck wear and compressor motor damage what the Dash pressure damage. May be worn out side between 200 and 250 psi is too much lower or higher shows is..., as this is a leak that needs to be repaired low sides up now. By ARX model and extended Kalman filter ) you have to have the AC turned on when! The correct reading to explain in words turns on when the A/C off. Side and 200 to 250 psi AC turned on Max when you add refrigerant the...
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