Observe the pressure gauges. Is there any resistance? I need shims to increase the 'air gap'; where would purchase the shims ? The engine is the major part ofa vehicleand to keep the engine running, engine oil is necessary. Typical faults of air conditioning systems and fault detection by ARX model and extended Kalman filter. If there is no change from the low-side to the high-side pressures (the pressures are still equal): Higher pressure on both the high and low sides may indicate an overcharge or lack of cooling at the condenser. The car is a 2006 Hyundai Accent. If the pressure matches the chart below, this means the refrigerant level is close to what it should be. JavaScript is disabled. 3) Partial blockage of the orifice tube/expansion valve and the evaporator. The dirt on this evaporator has restricted the airflow and caused a lack of cooling. 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. My mechanic says any bypass belt still will use the pulley or pass through the area of the compressor pulley. 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. Like something it trying to engage and then doesnt. If youre tracking down a wiring issue, Eautorepair.net is the better choice. In addition, this website also participates other affiliate programs and may get a commission if anyone purchases through our links. Replace expansion valve, flush and install in-line filter. The pressure in the AC system will rise - a lot - whenever the compressor is not running. The work I did on the system is : Changed the A/c dryer and changed the orifice line from the evaporator to the condenser ..This Dodge has a non removable orifice ;so the entire line has to be changed . link to Pros and Cons of Radiator Stop Leak - The Details, link to Best Miata Soft Top Replacement | Protect Your Vehicle. Alldatadiy.com, on the other hand, uses the factory diagrams. 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. yes, the electric fan closest to the radiator. U.S. Patent 6,324,854, issued December 4, 2001. High side of gauge reading zero, but the cab is cool. - improper routing or support of the piping or 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 However, it is always better to consult a mechanic before deciding to replace any part. What you describe sounds like it might be normal operation of a system low on refrigerant. Readings higher than the chart indicate an overcharged system while lower readings confirm a low level of refrigerant and a possible leak. For a better experience, please enable JavaScript in your browser before proceeding. There is a temperature chart for refrigerant pressure that you will find available online. Apologies for the delay. Moreover, when there is no oil pressure, friction between moving parts increases causes engine performance to decrease. When the fan becomes damaged, airflow through the condenser is This filter is often overlooked until it is entirely plugged up and allows very little airflow into the cab. Why would they call it a bypass belt if that is the case? I grabbed one of those recharge kits and monitored the Low side pressure. when you have abnormally high refrigerant pressure on the low side or suction side I suspect blockage in the refrigerant line or failed thermostatic expansion valve, What happen the low side very high pressure, Anon If the oil pressure is zero, then there will be metal to metal contact between machinery parts. The system is probably leaking. Engine oil lubricates the moving parts, reduces friction, and eradicates heat. Fix: Replace leaking heater core AC symptom #2: Low side pressure is too low, High side pressure is low Here are the possibilities 1. 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. Is compressor bad? When you shut off the AC you hear a hissing noise. However, Alldatadiy.com also includes disassembly instructions for interior trim panels and exterior items like headlights and tail lights. Any thoughts? 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. Fix: Remove excess refrigerant or evacuate and recharge with the correct amount. How are you going to do that? 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. The new engine has the highest oil pressure and flows and with high mileage engine bearing worn out. Question: I charged the A/C system. Fix: Clean condenser fins and check for dented condenser tubes. Yoshida, Harunori, Tatsuhiro Iwami, Hideki Yuzawa, and Masami Suzuki. 1. Fix: None needed. This is the reason you can't add refrigerant. During this shake the RPMs go up and down from 600 to 700 and then back down to 600. its hard to make a guess. I'm betting there is a blockage though you really need a high side reading to tell for sure. 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? The orifice tube has too large of an opening or the o-ring sealing the outside of the orifice tube is not sealing. Bad txv or tev. Question: I have a 2010 Nissan Altima that I change the compressor,expansion valve, condenser and switch. It is better to consult a mechanic. A low pressure cut-off will prevent the 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. PHI Learning Pvt. - omission of coiled slack to avoid tension or stress on the piping Low on r143a refrigerant, as this is a sealed system there is a leak some where. The air inside cab is down to 50 degrees. Any suggestions? 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. Oil pressure drops to zero when engine starts then goes to 60,while driving after warm,pressure drops down 4.3 V6 vortec engine The 4.3 engine should have 20 to 30 psi at idle cold and around 50 to 60 psi running down the road. The filter looks like a small air filter from a car. Why would my Dodge's AC pressures be so different? Doors control the direction of the airflow created by the electric blower motor. What should be my next step? Usually, the high side is really high and low side really low. They include wiring diagrams and technical service bulletins. Question: What causes the hig side pressure to be low? What makes the coupler not to stay secure? I vacuumed the system and put new refrigerant. 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. Come join the discussion about MazdaSpeed performance, modifications, classifieds, troubleshooting, maintenance, and more! The A/C gauge reads zero pressure on the "low side." 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 The switch is located near the expansion valve. Then, since no more refrigerant is flowing, the evaporator warms up, the ice melts and you get warm air. Fix: Replace a bad blend door actuator or faulty heater control valve or repair a faulty blend door or blend door linkage. Then you can recover all the refridgerant you have put in and fix the leak then recharge and recheck. The high- and low-side pressures should be equal. I tried recharging the A/C today and found out another thing. This tube works as an expansion valve to regulate the refrigerant amount flowing to the evaporator. If the problem exists, it needs engine replacement. 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. Before deciding to replace the compressor, other components that you may check are the pressure switch, expansion valve, and the compressor clutch. 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. I have to bypass with the belt. Evacuate and check for blockage. Ambient temperature 30 degC. You can measure the refrigerants pressure at a given temperature. High side reading is normal but low side immediately pegged the gauge and didnt move. Ltd., 2010. 1. A clogged filter is due to leaks therefore needs replacement. 1. Eautorepair.net redraws factory wiring diagrams in color and includes the component, splice and ground locations right in their diagrams. Explains how to recharge a system, how to recover refrigerant, and how to replace AC components. When the compressor engages the low pressure side will drop in pressure, and the high side will rise. An oil pump is an essential part of the lubricating system. "Static pressure" is measured when the system is not running. Charge with DYE and retest with a black light. JavaScript is disabled. Electronic actuators with position sensors are very popular to move the doors to direct the airflow and control temperature. Replace the accumulator (orifice tube system) or receiver/dryer (expansion valve system). Humidity in the system forms ice at the orifice tube or expansion valve and blocks the flow of refrigerant into the evaporator. I also agree with the others that you might consider getting an A/C shop to look at this as A/C work can be a bit dangerous on top of causing even more damage to the system. @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 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 systems with rear ac hold more refrigerant, usually about 3.8 pounds. Your Car Is Losing Coolant But No Leak: What Should You Do? Ling, Jiazhen, Yunho Hwang, and Reinhard Radermacher. If you missed part I, start here. Start the engine and turn on the air conditioner. No hot water valve is needed because in cool mode the door closes off airflow through the heater core. Which switch are you referring to?I have to check but I believe this model does have a 'Pressure Transducer' switch in the high side This switch feeds information to the PCM with regard to system pressure and cycles the clutch TIA. The compressor clutch stays engaged and the pressure readings stay the same. 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? - Causes of a refrigerant pipe leak due to cracking, Causes of a refrigerant pipe leak due to cracking might include Pressure Low: 0. 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. 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. Also, check if the compressor clutch engages and rotates the compressor when the AC is on. A/C was working great and then suddenly stopped.Low pressure side is around 40psi until the clutch kicks in and then drops to If there is any liquid refrigerant present (and there is in a normally charged system) then the pressure goes to the saturation pressure. The filter may be located under the dash or on the heater box in the engine compartment. Twice I have tried to charge the A.C. system to the proper pressure. This could be normal if outdoor temperatures are very high. Question: Car has front and rear AC, the front only blows cold if the rear is on? Tried adding refrigerant, the low pressure needle does not move. Keep a check for external oil leaks; it can cause oil drops. The blockage or stuck expansion valve restricts the flow of refrigerant into and out of the evaporator. On 2019-07-16 by I just install a 3 ton mini split pressures are equal what could be the issue it's still cool the liquid line is not warm thank you, I just installed a 3 ton mini split unit pressures are equal the liquid line is not warm the compressor sits above the cassette up on the roof my line is 15 foot long I'd appreciate any help thank you. Install an in-line filter to prevent re-occurrence. Answer: Sounds like poor airflow across the condenser. 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 old systems used a sight glass to charge the systems. Getting no guage pressure on York heat pump in cooling mode but compressor is running. 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. How To Fix Sagging Headliner Without Removing In Less Than 10 Minutes! In most cases, their diagrams are right from the factory manuals. Bad AC Compressor. This could be normal if outdoor temps are very low. Actual readings will vary according to ambient temperature. Oil pressure turning to zero can cause damage to the engine. There are several constraints that cause this state. Question: Why does the ac cut off every time I make a turn? ", The Fora platform includes forum software by XenForo, Amazon.com: Mastercool (81490) R134A Valve Core Remover Installer: Automotive, VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada, driveaccord.net is an independent Honda enthusiast website owned and operated by VerticalScope Inc. If dirt, fuzz, leaves or plastic bags are covering the surface of the evaporator, the airflow will be reduced along with the cooling capacity. If the system is continuing It was 85 outside and I'm guessing about 40% humidity. Route checkups prevent major problems. AC Low Side High, High Side Low: Why Does This Happen? Turned off AC, and it climbed to what looks like 75PSI well off. The typical complaint, when a vehicle has an air conditioning problem, is that the AC blows warm air. I just hooked up a set of gauges a few moments ago. The TXV is stuck open or the thermal bulb is not sensing the temperature correctly. Evacuate the system and recharge with the correct amount of refrigerant. 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.. 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. Fan turns on when the A/C is turned on and turns off when the A/C is off. When I switch it off it still blows semi cool air. In most cases, their diagrams are right from the factory manuals. What are the effects of low refrigerant pressure at the compressor or in the system? When running, but AC turned off, it had full pressure. 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. Refrigeration and air conditioning technology. There are tools that will replace the valve cores with no r134a refrigerant loss. - defective or mechanically-damaged copper tubing Low side is way to high. It can lead to engine failure. What was the ambient temp? For a better experience, please enable JavaScript in your browser before proceeding. You will not receive a notification when a response to your question has been posted. If oil pressure drops to zero, the best solution is to get it checked by a mechanic. To gauge the pressure, hook up a gauge set to the AC system and record the pressures of both low and high sides. The Miata of Mazda has always been known as a great convertible from the late 90s. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta, GA (United States), 1996. Clutch plate air gap between the plate and the pulley in specs. Does that make sense? Fix: Check for leaks and repair. Eautorepair.net redraws factory wiring diagrams in color and includes the component, splice and ground locations right in their diagrams. Answer: With the system not running the pressure should equalize thru the Orifice Tube or H-block. Does the pressure go up? This could be normal if outdoor temps are very low. 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. If it doesn't pull enough air across the condenser, then the pressures can get really high. Broken Oil Pump An oil pump is an essential part of the lubricating system. But the high side is extremely low. 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 system must be evacuated before charging. Cooling fan problem, plugged or blocked condenser are the probable causes. If the liquid line is not warm on your system you may face these problems. Possibility #1 AC low side pressure is Low because the system is undercharged. The effects of poor oil return to the compressor include first reduced cooling capacity and later damage to the compressor motor. Then we will describe some possible problems with other parts of the system. The solution to this problem is changing the bearing. For cooling to take place, air has to flow freely across the evaporator. This likely means you're low on refrigerant. 2. It works but, the next day doesnt work. Pressures are 120headover 118 suction low side. Riffat, S. B., C. F. Afonso, A. C. Oliveira, and D. A. Reay. Could it be the hi pressure switch? The problem is that the defective oil sensor gives a false reading. If the reading is normal, replace the sensor. Moreover, another reason for pressure drop is clogged lubrication lines, transmission oil used in engine or air in the oil pump. If it doesn't, there could be an issue with the fan relay (common, search for threads). 5. Adj. 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. Is voltage being applied to the clutch coil? This article is accurate and true to the best of the authors knowledge. 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. I would do an evacuate and recharge first, then do a pressure check. That saves a lot of time because you dont have to refer back to the component locator or circuit locations. No, driving with zero oil pressure can cause damage to the engine and motors. Not-so-cool air is being blown out. However, theres also the possibility that the system has gotten overcharged with too much refrigerant. This is the second part of a series on AC pressure gauge readings. Note: appearance of your Comment below may be delayed: if your comment contains an image, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Air Conditioning (AC) System Operation with TXV or Orifice Tube. 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. The system is overcharged. Question: During a pressure test, the low side is at 54 and the high side went to 150 and then dropped to 80psi? The Reasons for AC Low Side High, High Side Low Pressure, A Safe and Secure Way to Flush AC System After Compressor Failure. The high side reads 65 psi. Thanks. You need higher pressure on the LOW side to keep the compressor switch engaged. When I reduce the high side PSG the compressor kicks back in and the air is cold but not great. 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 Refrigeration & Air Conditioning Technology. 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.