Car AC Diagnosis of Various Symptoms Dedicated Thread

[wasim625]

Would someone please shed some light on this

No it won't.
And please don't block or disconnect your heater pipes. By doing that water/coolant is trapped inside the heater and slowly eats up the aluminium heater due to which we have to service and repair the heater on every winter season.
Secondly, No it doesnot affects AC cooling. Mechanics disconnect/block heater pipes because the air direction flap inside the HVAC cabin that lets you have hot air or cool air in the cabin doesn't sits and seals the air from heater properly due to which we get mixed hot and cool air in cabin in other words less cool air which drops AC performance. To solve this problem mechanics cut off/block the heater pipes so there will be no Hot air mixing from the heater side and AC will perform better.

[afnan.bashir]

no it wont, the heater is only active if you select the heat position on the control panel.

Well my car has a valve like stuff that is controlled by HVAC system which automatically closes . But even then i can feel extremely hot heater core when i touch it

[Xulfiqar]

Well my car has a valve like stuff that is controlled by HVAC system which automatically closes . But even then i can feel extremely hot heater core when i touch it

your car has climate control ac?

[afnan.bashir]

your car has climate control ac?

Yes with DUAL option that allows different temperatures for passenger and driver

[Xulfiqar]

Yes with DUAL option that allows different temperatures for passenger and driver

then the heater core is kept hot to provide a heated source of air, The airflow then is controlled by air flaps and guide doors to blend the heated air from heater and cool air from the evaporator to meet the requirements set by the users from the dashboard panel.

[wasim625]

By the way if a system is over charged and we want to bleed some refrigerant out whats the proper procedure for that? Compressors should be running or not we should bleed from vapour side or liqud side etc.

[Xulfiqar]

By the way if a system is over charged and we want to bleed some refrigerant out whats the proper procedure for that? Compressors should be running or not we should bleed from vapour side or liqud side etc.

there are no laws in Pakistan against venting R134a into the air, however its harmful to the environment and also a bit expensive, to reclaim it into a container you need a recovery machine that also isolates oil from the gas.

you can contact some high end ac shops to ask if they have a recovery machine - that way you also know how much refrigerant was in the unit.

If you are going hawaee fire type then vent it out from the vapour side only. not the liquid side.

Before doing such - test the run pressures and determine if the unit is actually overcharged.

[wasim625]

there are no laws in Pakistan against venting R134a into the air, however its harmful to the environment and also a bit expensive, to reclaim it into a container you need a recovery machine that also isolates oil from the gas.

you can contact some high end ac shops to ask if they have a recovery machine - that way you also know how much refrigerant was in the unit.

If you are going hawaee fire type then vent it out from the vapour side only. not the liquid side.

Before doing such - test the run pressures and determine if the unit is actually overcharged.

Lol hawai fire he chalne dien bhai pahle konsa idar europe ban gya hai :v

About the test, this what i have in my mind:
1- start the car Open windows and doors and On the AC let the system run for 5 minutes and pull atmospheric Temp. from google (my thermometer broke last night ) i have already downloaded R134a PT chart.

2- Hook the gauges up and see the readings if they are upto the spec according to PT chart (I'll allow a little above or below than specs values since my atmospheric Temp. is not accurate.
Question:
should i rev the engine?
Should engine rpm be held at a rise say 1500 or i should leave it alone at and take my measurements at idle?

3- then if needed Hawai Fire the refrigerant in air and ignore being irresponsible lol.

By the way i am thinking of discharging the system by the amount of 3-5 PSI per turn and then tight the valves again and let the system stable for 2-3 minutes and repeat the process until my PSIs are in spec to the PT chart.

And at last, feel good about a job well done.

[wasim625]

so i went to my AC wala today. Asked him to hook up the guages and check the pressures and the first thing i had to deal with was only his low side guage was working. So he hooked only the low side guage and the pressure was around 60 PSI with ambient temperature to be 37C - the chart says its should be 50-55C - so i asked him to release some gas - keeping in mind you guys comments that i might have an overcharged system - the mechanic said No your system indicates a low referigrant - based on he touching the low side pipe and high Head temp. - i insisted him to just release the gas and bring it down to 50PSI. He did. Then i noticed even decreased performance in Cabin. The mechanic told me the head pressure i am heaving is dangerous for AC compressor it should never ever exceed 55 PSI. I told him the theory - the chart - behind this PSI reading. That was ofcourse new to him he kind of took interst in what i was telling him and then said i should go to Suzuki 3S dealership and ask them to hook both guages and that i should tell them this and ask them what can be the problem. That sounded reasonable to me so i went to 3S dealers there technician was on leave. so i headed back to my AC wala he then said sir according my experience your head pressure is high due to low referigrant charge. I said ok dude do work according to your theory and we'll see what comes out. He started charging the gas and pressure began to drop. He kept on charging and stabilized the pressure at 40PSI - which according to chart should be 45-50 as temp droped - so i didnt argued with him about that - he by the way stabilized it at 40PSI cause it works for him. He would have charged it at 40 PSI even if the temp outside was 28Cs - Next the head pressure stabilized he asked me to sit in the car and check the AC which i did. He sat with me and started talking about this 134a PT chart and the theory behind it so we talked about 10 miniutes or something. Then he said lets check the head pressure if it has changed - he said, Dua karna na he change huwa ho yar ye sambhalana bht mushkil hai - we checked the pressure and it wasnt changed. i could feel cooling in the car everything seemed fine to me.

Now my questions::
the PT chart is followed is attached.

At the end it says if Both Pressures are Low then we should ADD the gas. Whereas if both pressure are High - than the specs - the we should release the gas. i had a higher valued Low side pressure still i had to ADD the gas but to release it. What am i missing here?

• He was checking the pressure while the blower speed was at 3. He said it should be at 2 or 3. I asked him How can he determine that like for example Hyundai Santro's blower speed at 3rd point will be different from the blower speed of Suzuki alto at number 3 so how can it be a set rule for that?
  He started beating about the bush and topic was changed. Clearly he could not answer that.

So, what should be the blower speed while charging the system or checking the system for appropriate pressures?

[Xulfiqar]

How was he claiming high head pressure when he did not have the high side gauge in place.

Low gas charge does come up as high suction pressure as the txv opens up maximum to flood the evaporator coil .

To test any txv system the liquid line shows the correct workings

[wasim625]

How was he claiming high head pressure when he did not have the high side gauge in place.

Low gas charge does come up as high suction pressure as the txv opens up maximum to flood the evaporator coil .

To test any txv system the liquid line shows the correct workings

Exactly bhai i was really concerned about him not using the high side gauge. Mtlb ye to jan bhooj kar khud ko andha karny wali bat hai..

Secondly, whats with this "Blower Speed" concept?

[abdkhan2]

AOA,when i spray some water on condencer cooling increases and very less cooling in evening time?
does it indicates low amount of refrigerant or low quality refrigerant

[afnan.bashir]

AOA,when i spray some water on condencer cooling increases and very less cooling in evening time?
does it indicates low amount of refrigerant or low quality refrigerant

You need to do more tests than that but considering the condenser water test, it shows your fans are not cooling well enough and condenser is not dissipating required heat

[wasim625]

AOA,when i spray some water on condencer cooling increases and very less cooling in evening time?
does it indicates low amount of refrigerant or low quality refrigerant

Hook the pressure guages and compare the readings with r134a PT chart. And see what are you having in the system.

[abdkhan2]

You need to do more tests than that but considering the condenser water test, it shows your fans are not cooling well enough and condenser is not dissipating required heat

any gas problem.as fans are doing well

[afnan.bashir]

for that i said you need to do further tests. Hook manifold gauges to high and low sides. Tell us the ambient temp and pressures of both sides

[SER_GTR]

so i went to my AC wala today. Asked him to hook up the guages and check the pressures and the first thing i had to deal with was only his low side guage was working. So he hooked only the low side guage and the pressure was around 60 PSI with ambient temperature to be 37C - the chart says its should be 50-55C - so i asked him to release some gas - keeping in mind you guys comments that i might have an overcharged system - the mechanic said No your system indicates a low referigrant - based on he touching the low side pipe and high Head temp. - i insisted him to just release the gas and bring it down to 50PSI. He did. Then i noticed even decreased performance in Cabin. The mechanic told me the head pressure i am heaving is dangerous for AC compressor it should never ever exceed 55 PSI. I told him the theory - the chart - behind this PSI reading. That was ofcourse new to him he kind of took interst in what i was telling him and then said i should go to Suzuki 3S dealership and ask them to hook both guages and that i should tell them this and ask them what can be the problem. That sounded reasonable to me so i went to 3S dealers there technician was on leave. so i headed back to my AC wala he then said sir according my experience your head pressure is high due to low referigrant charge. I said ok dude do work according to your theory and we'll see what comes out. He started charging the gas and pressure began to drop. He kept on charging and stabilized the pressure at 40PSI - which according to chart should be 45-50 as temp droped - so i didnt argued with him about that - he by the way stabilized it at 40PSI cause it works for him. He would have charged it at 40 PSI even if the temp outside was 28Cs - Next the head pressure stabilized he asked me to sit in the car and check the AC which i did. He sat with me and started talking about this 134a PT chart and the theory behind it so we talked about 10 miniutes or something. Then he said lets check the head pressure if it has changed - he said, Dua karna na he change huwa ho yar ye sambhalana bht mushkil hai - we checked the pressure and it wasnt changed. i could feel cooling in the car everything seemed fine to me.

Now my questions::
the PT chart is followed is attached.

At the end it says if Both Pressures are Low then we should ADD the gas. Whereas if both pressure are High - than the specs - the we should release the gas. i had a higher valued Low side pressure still i had to ADD the gas but to release it. What am i missing here?

- He was checking the pressure while the blower speed was at 3. He said it should be at 2 or 3. I asked him How can he determine that like for example Hyundai Santro's blower speed at 3rd point will be different from the blower speed of Suzuki alto at number 3 so how can it be a set rule for that?
He started beating about the bush and topic was changed. Clearly he could not answer that.

So, what should be the blower speed while charging the system or checking the system for appropriate pressures?

Thing Finishes Logically When He Didn't Hook High Side And Only Work on Low Side.....! Now He's On Hit And CHECK Method....!!

SO All This Logical Explaination Fails When You Don't Even Hook A High Side.....!

You Think HVAC Manifold Gauges Manufacturers Are Fool To Make High And Low Side Gauge And They Are Expert To Only Use LOW Side

Making Them Understand And Explain Is Like Teaching A Buffalo...Maybe You Can Teach A Buffalo But Not Them..This Is Why I Not Anymore Go To Any Of EXPERT Ustaads Out There

[SER_GTR]

for that i said you need to do further tests. Hook manifold gauges to high and low sides. Tell us the ambient temp and pressures of both sides

Hum Ne Logon Ko Kis Kaam Dhandhey Pe Lagadiya Just Think

[wasim625]

Thing Finishes Logically When He Didn't Hook High Side And Only Work on Low Side.....! Now He's On Hit And CHECK Method....!!

SO All This Logical Explaination Fails When You Don't Even Hook A High Side.....!

You Think HVAC Manifold Gauges Manufacturers Are Fool To Make High And Low Side Gauge And They Are Expert To Only Use LOW Side

Making Them Understand And Explain Is Like Teaching A Buffalo...Maybe You Can Teach A Buffalo But Not Them..This Is Why I Not Anymore Go To Any Of EXPERT Ustaads Out There

Exactly. Its Hit And Trail method. Lag gyya to Balley balley na laga to ALLAH ke hawaley lol.

What do you think about this Blower speed method i wrote in the post.

[Horse_rider]

My santro having toyota duet compressor and new condensor gives excellent cooling, the only problem is when the car is at signal the cooling decreases. The radiator and its fan is kabli 660cc car's. radiator is in very good condition but fan is I think not enough for the condensor. Should I change the fan? To which one if changing is required.

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