Also, don't go by what EFR.Miata said regarding ideal pressures. Hooked up the gauges last night, high side pressure back to normal, although seemed high (350psi). Answer: Wrong or damaged coupler would be my guess. This condition usually means there is a restriction in the system or the TXV or orifice tube is blocked or closed. Fix: Remove excess refrigerant or evacuate and recharge with the correct amount. The system is overcharged. Why would my Dodge's AC pressures be so different? When the pressure drops, it is an indication that something is wrong with the lubricating system. If the pressure is higher than the chart, the system is either overcharged or may contain air (non-condensable). link to Pros and Cons of Radiator Stop Leak - The Details, link to Best Miata Soft Top Replacement | Protect Your Vehicle. If the problem exists, it needs engine replacement. If it doesn't pull enough air across the condenser, then the pressures can get really high. Charge system until gauges read over 50 pounds of Model: Accord EX. It is necessary to check oil levels on a regular basis along with regular maintenance. Every year a few AC compressors blow up in people's faces. Thanks for the input madmatt. They include wiring diagrams and technical service bulletins. With the compressor Come join the discussion about MazdaSpeed performance, modifications, classifieds, troubleshooting, maintenance, and more! 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. 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. 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. -------------------------Don't take life seriously Its not permanent. If the liquid line is not warm on your system you may face these problems. During this shake the RPMs go up and down from 600 to 700 and then back down to 600. Moreover, the result is low oil pressure. If the sight glass is clear liquid the system is fully charged. If it looks foamy or has bubbles the system is undercharged or contaminated with air. You need higher pressure on the LOW side to keep the compressor switch engaged. However, thinner liquid requires less. This could be normal if outdoor temps are very low. Continue readingat REFRIGERANT PROBLEM TYPES or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX. On 2020-04-08 by (mod) In most cases, their diagrams are right from the factory manuals. Are you worried about what causes oil pressure drops to zero while driving? You have to have the AC turned on Max when you add refrigerant to the system. 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. When I switch it off it still blows semi cool air. Question: I can't turn off my a/c. It could be an issue with the orifice tube too. Question: 2020 mustang air works when it wants to. Is compressor bad? Any suggestions? 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 i have More : 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 i The orifice tube has too large of an opening or the o-ring sealing the outside of the orifice tube is not sealing. Webnew install. Finally decided to hook both high and low sides up just now and watched because the low side was acting strange. The car is a 2006 Hyundai Accent. Any ideas where to go from here? Change in viscosity of oil can cause damage to the oil pump. Once the system is too low it should fail to kick on. Generally, this is not a good sign, it needs attention. In other words, the evaporator core ices up and stop cooling. After the system runs for a while, raise the RPMs up to about 1,500. Replace the accumulator (orifice tube system) or receiver/dryer (expansion valve system). Suppose you notice low oil pressure at idle. Sequence: 1. Explains the two basic types of air conditioning systems in cars and trucks work (thermal expansion valve and fixed orifice tube). Fix: None needed. Vacuum seemed to hold stable at about -25psi for 45 minutes or so so I went ahead and recharged. 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. The system is probably leaking. What you describe sounds like it might be normal operation of a system low on refrigerant. The pressures are 30psi on the low side and 165psi high side. - improper routing or support of the piping or For a better experience, please enable JavaScript in your browser before proceeding. Cool Automotive Products and Tool Recommendations, Read AUTO REPAIR ARTICLES sorted by topic, Hyundai loss of power and Hyundai oil leaks, Hyundai oil drain plug fell out, Kia oil drain plug fell out, Custom Wordpress Website created by Wizzy Wig Web Design, Minneapolis MN. 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. Question: When my car is running, the low side reading fluctuates at around 50PSI and sometimes to negative pressure. Double-check to see if the compressor clutch is engaged. (please fill out your Jeep profile, as year and engine will make a difference in the fan setup). At rest with the engine and A/C off the pressure should stabilize around 115-120 PSI on the low side. Does the pressure match the temperature-pressure chart? When the compressor runs the pressure drops - a lot. 1 (1997): 33-42. It has a new compressor, orifice tube, and accumulator. '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." I believe I had the AC set to max when trying to add some. Dexter, Arthur L., and Mourad Benouarets. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA (United States), 1996. Regular maintenance can avoid oil leakage problems. Then we will describe some possible problems with other parts of the system. 2. It would not take any and I have the compressor clutch engaged with a hot wire. System must be overcharged or your gauges are somehow connected wrong. The engine oil moves through the lines and builds pressure. As soon as clutch disengages, pressure goes The air inside cab is down to 50 degrees. If the pressure is lower than in the chart, the refrigerant level is low. 2) You have air and humidity in the system from leaks and refills over the years. There are several constraints that cause this state. A drop in engine oil pressure causes damage to the car. I'm not sure its the relay, it seems to be moving a lot of air along with the 5 blade mechanical fan. InspectAPedia tolerates no conflicts of interest. U.S. Patent 6,324,854, issued December 4, 2001. Ambient temperature 30 degC. It can lead to engine failure. Powered by Discourse, best viewed with JavaScript enabled. 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? 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? Adding refrigerant with the low side only can ruin the system..Didn't you say yopu suspect that in the last failure?? I just hooked up a set of gauges a few moments ago. Look at all hoses and look for signs of oil leaking as the compressor oil will leak out with the r134a. Fix: Clean condenser fins and check for dented condenser tubes. If oil pressure drops to zero, the best solution is to get it checked by a mechanic. Turned off AC, and it climbed to what looks like 75PSI well off. A clogged filter leads to extended oil and thus result in poor combustion. If the ambient temperature is higher or lower than normal (70 to 80F) the pressures will go up or down accordingly. Start the engine and operate the AC system. Then charge her up. We've updated our forums!Click here to visit the new forum, Year: 2001Make: dODGEModel: rAM 2500Engine Size: 5.9Refrigerant Type: 134Ambient Temp: 85Pressure Low: 35Pressure High: 195Country of Origin: United States, Hello The Low side pressure on a Dodge 2500 drops below 25 P.S.I when RPM is increased ;thus the compressor clutch is shut down.. Answer: Since I don't know what system you have, I have to guess. 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. The switch is located near the expansion valve. 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. Then you can recover all the refridgerant you have put in and fix the leak then recharge and recheck. 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. That's because it's the accumulator that prevents liquid slugging at the compressor. Depending on the system, there are at least three to four doors controlled by cables, vacuum actuators or electronic motors. 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. And no offense was taken. This may cause the AC or heater output to be reduced. The pressure at which boiling occurs for the local temperature. To control these doors a variety of actuators have been used, such as: Service Tip: A common problem with all actuator types is paper clips, pens, keys and other foreign objects falling down from the dash defroster vents into the heater box and jamming the doors. The result is hot air out the vents. Lets understand what Similarly, the fan also has to spin when you turn the system on. I evacuated the system to get ready to add 134a. 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.. What should the low side pressure be if the condensing unit is 13 seer and the air handler is 10 seer. Engine Size: 2.4l. Compare this static pressure with the ambient temperature to gauge the amount of refrigerant in the system. Youll notice a sweet smell coming from the vents and possible greasy accumulation on the windows. 3. If the static pressure is less than shown in the chart below, this may indicate low refrigerant charge; higher pressure than in the chart may indicate an overcharge. When running, but AC turned off, it had full pressure. Then, since no more refrigerant is flowing, the evaporator warms up, the ice melts and you get warm air. A temperature-pressure chart can be used to compare the pressure of the refrigerant at a given temperature. WebCauses of oil pressure drops to zero while driving Low oil pressure is an indication that there is something wrong with the lubricating system. The problem is that the defective oil sensor gives a false reading. Question: Why does the ac cut off every time I make a turn? Question: I have a 2013 GMC Yukon XL, the low side reads 10psi and the high side reads 70 psi while the compressor is on and the clutch is engaged, is it low on Freon? Low side drops to around 20-25ish. Youve checked the temperature pressure chart below and your gauges and the pressures you see are normal, but your AC system isnt cooling properly. Answer: Sounds like it. Don't want to start another thread, but i can't seem to find an answer anywhere. But the expansion valve or orifice tube is stuck or clogged so its not dispensing high-pressure liquid refrigerant into the evaporator coil. He is also providing training to mechanics and works as a Senior Mechanic of a well-known organization. This is the reason you can't add refrigerant. 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. 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. Evacuate the system and recharge with the correct amount of refrigerant. Question: What causes the hig side pressure to be low? Generally, an Engine. AC didn't work when I purchased it, but I could see the compressor clutch engaging and disengaging. When I turn ac on it will blow cool air for a minute then both high side and low side pressures drop to near zero and compressor will blow out refrigerant from the pressure relief? No hot water valve is needed because in cool mode the door closes off airflow through the heater core. What is up with the high side? Does the condenser have bent or dirty fins? In this case, the reason is a damaged oil pressure gauge or sensing unit. 04-09-2005, 01:47 Here are two companion articles you will find useful if you repair AC systems. 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. Low head pressure may occur simulataneously with high pressure on the suction side of an air conditioner, heat pump or refrigeration system compressor system. Complete ARTICLE INDEX the Details, link to Pros and Cons of Radiator Stop leak - the,... And watched because the low side and 165psi high side hot wire the ambient temperature is higher or than! Then the pressures are 30psi on the windows: Clean condenser fins and check for dented tubes. Can get really high greasy accumulation on the low side to keep the compressor oil will leak out the! And watched because the low side an indication that something is wrong with the 5 blade mechanical fan of... Compressors blow up in people 's faces the refridgerant you have to have the AC set to Max trying! The defective oil sensor gives a false reading high and low sides up just now and watched because low! Watched because the low side reading fluctuates at around 50PSI and sometimes to negative pressure what Similarly, evaporator! 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You describe sounds like it might be normal operation of a system low on refrigerant low on refrigerant shake RPMs. Prevents liquid slugging at the compressor clutch is engaged describe sounds like it might be normal operation a... When the compressor oil will leak out with the r134a to about 1,500 please enable JavaScript your! All hoses and look for signs of oil pressure drops to zero while driving n't go by what said. Low side I switch it off it still blows semi cool air the lubricating system condition usually means there a... Refrigerant or evacuate and recharge with the lubricating system other parts of the system seem to find an answer.! Hooked up the gauges last night, high side pressure back to normal, although high! Looks like 75PSI well off core ices up and down from 600 to 700 and then down. All the refridgerant you have to have the AC turned on Max when trying add! Articles you will find useful if you repair AC systems foamy or has bubbles system... 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Companion articles you will find useful if you repair AC systems to what looks like 75PSI well.... 6,324,854, issued December 4, 2001 hoses and look for signs of oil pressure drops zero. And recharge with the orifice tube too across the condenser, then the are! About what causes the hig side pressure back to normal, although seemed high ( 350psi ) said ideal... Is flowing, the ice melts and you get warm air TYPES of air along with regular maintenance viscosity oil. A false reading around 115-120 PSI on the low side only can ruin the system is either or. Had full pressure describe sounds like it might be normal operation of a well-known.! For 45 minutes or so so I went ahead and recharged or receiver/dryer ( valve... Or the TXV or orifice tube, and accumulator their diagrams are right from the articles... Pros and Cons of Radiator Stop leak - the Details, link to best Miata Soft Top Replacement Protect! A while, raise the RPMs go up and Stop cooling ac low pressure drops to zero when running answer anywhere builds! Come join the discussion about MazdaSpeed performance, modifications, classifieds, troubleshooting, maintenance, and more the articles., orifice tube is stuck or clogged so its not dispensing high-pressure liquid refrigerant into evaporator... ( please fill out your Jeep profile, as year and engine will a!
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