Car air-con

[Apple-Tree]

Since you asked about it.

 

A OK car aircon, like your home aircon or refrigerator, do not need to "Top Up Gas" or "Add what oil" one lor.

 

First 5~6 years of my car usually nothing done except change filter every CNY lor.

 

My papa mama home aircon 17 years never do servicing or top up gas or whatever. Just vacuum and wash filter every 6mth ba.

My home 10 years never do servicing or top up what one.  

 

 

Then, for car, 6~7 years .......  things start lor :

 

a) Discharge pipe is USUAL the first issue lor as it experience the highest pressure lor.

b) Then the Evaporator lor, leaking lor (Also Change Expansion valve and suction pipe) Change suction pipe because of the dryer.  If dryer not integrated, then no need to change lor 

c) Then ownself do lor

 

 

Gas Thermodynamics 101 - Gases pressure a strong function of temperature lor.  Looking at that fancy gauge has not much meaning one lor without checking the temperature lor.  Mechanics usually anyhow turn and turn, then suddenly aircon cold liao lor.

 

In the gauge, there is a pressure scales and in one of the inner scale show temperature lor.  The scale should read like lower blue line pressure lower temperature lor.  So actually, just before your aircon about die, you should suddenly feel that the aircon is much cooler then normal one and then it suddenly blow hot air lor.  

 

If you want to top up, make sure the mechanic check temperature and check gauge, and after 15mins max aircon.  The temperature at blower is 8~10C lower than ambient and the pressure gauge blue line (Low P side), NEVER touch 0C.  Touch 0C for that amount of gas means your evaporator is frozen with ice lor - May damage evaporator and not cold as the effective surface area is reduced - You get a feeling like the air is damp and cold lor.

 

OK.

 

Gas need to be in the exact amount in grammes.  My new carens need 550g of R134A.  So how to know you have 550g ? Either do very detailed measurement of the supercool state of the aircon vs pressure OR empty all gas, top up gas with a weighing machine lor.

 

So troublesome, no need to top better.  Only my first car, I kuku don't know, top until die lor.

 

OK,

 

Aircon Oil, also need to be exact one.  I also never top what oil one lor.  Does it matter the mechanic top up 15~20CC of oil ??

You ONLY need to top up oil when you CHANGE AIRCON component.  For every car, you can get a table for it one.  For example, if you change Discharge pipe, you need to top up 20CC of Oil for a Kia Carens III (UN), change evaporator add 50CC, change compressor another volume one. Usually or always, change compressor no need to add oil because the manufacturer would have added for you.

 

Too much oil, not cold. Too little oil, compressor die.  

 

So how, No Change No Add best.

 

OK

 

Vacuum Pump, How long to evac air ?  45mins, the vac pump need to run for AT LEAST 45mins to suck as much as air as possible.  Not 5~15mins OK, no pressure and start adding gas.

 

Why suck for 45 mins when after 5~mins the low pressure reach the lowest point ? Because water kill aircon too, when under low pressure water become a gases state lor.  And it is a very slow process, especially water in dryer.  

 

OK

 

How to detect leak ? You can actually add about 20~30CC of fluorescent oil into your aircon lor.  If there is a leak, use a UV touchlight you can detect where is the leak lor.  Very popular in US and Europe as owner like to ownself detect first then look for mechanic lor.

 

Good aircon don't leak, if it leak, usually need to change something.  If anyhow top up, most probably ownself damage aircon due to over pressure lor.

 

OK.

Usually aircon not cold is radiator fan not running properly due to connector issue lor.

 

 

Go youtube, a lot of channel on auto aircon repair and detection.

 

Good luck.

 

 

 

 

How does the mechanic detect leak? use vacuum pump and gauges? and is there a need to top up compressor lubricant? i notice most people only bother with refrigerant only

 

it seems impossible to 100% to prevent leaks.. and those keep asking us to top up seems like con money..

 

[Ghost777]

Hi just for those who really have car air con problem you may try to look for MARK COOL at woodlands. The price is reasonable. Previously my accord also don't know what happen start engine air con not cool takes about 5min than also start to cool. End up I pay $20 for a switch inside for replacement everything back to normal. Not advertising. Just share my experience with MARK COOL. you may call up look for Jackson. Nice guy. Won't anyhow charge.

Edited August 6, 2018 by Ghost777

[Johnnylim]

Since you asked about it.

 

A OK car aircon, like your home aircon or refrigerator, do not need to "Top Up Gas" or "Add what oil" one lor.

 

First 5~6 years of my car usually nothing done except change filter every CNY lor.

 

My papa mama home aircon 17 years never do servicing or top up gas or whatever. Just vacuum and wash filter every 6mth ba.

My home 10 years never do servicing or top up what one.  

 

Just curious, u mentioned your home air con never do servicing before, just vacuum & wash filter. May I know how the usage like? Eg use  everyday or etc etc etc?

[Apple-Tree]

Oh, everyday 10pm to 4am lor. January-February whole month never on one.

 

To be more precise, if temp is 28C or higher, on aircon sys 3 all lor.  Typically, 24hours, my meter will jump about 10~15 units ba. - Everything in, Light, PC,TV, Fridge etc ..........

 

 

Sometimes, when temp drop to very cold like this year 18~22C, I also on aircon because the wall is wet lor.  Need aircon to suck up all the moist lor.

 

 

 

 

Just curious, u mentioned your home air con never do servicing before, just vacuum & wash filter. May I know how the usage like? Eg use  everyday or etc etc etc?

 

[smoothtalker]

Since you asked about it.

 

A OK car aircon, like your home aircon or refrigerator, do not need to "Top Up Gas" or "Add what oil" one lor.

 

First 5~6 years of my car usually nothing done except change filter every CNY lor.

 

My papa mama home aircon 17 years never do servicing or top up gas or whatever. Just vacuum and wash filter every 6mth ba.

My home 10 years never do servicing or top up what one.

 

 

Then, for car, 6~7 years ....... things start lor :

 

a) Discharge pipe is USUAL the first issue lor as it experience the highest pressure lor.

b) Then the Evaporator lor, leaking lor (Also Change Expansion valve and suction pipe) Change suction pipe because of the dryer. If dryer not integrated, then no need to change lor

c) Then ownself do lor

 

 

Gas Thermodynamics 101 - Gases pressure a strong function of temperature lor. Looking at that fancy gauge has not much meaning one lor without checking the temperature lor. Mechanics usually anyhow turn and turn, then suddenly aircon cold liao lor.

 

In the gauge, there is a pressure scales and in one of the inner scale show temperature lor. The scale should read like lower blue line pressure lower temperature lor. So actually, just before your aircon about die, you should suddenly feel that the aircon is much cooler then normal one and then it suddenly blow hot air lor.

 

If you want to top up, make sure the mechanic check temperature and check gauge, and after 15mins max aircon. The temperature at blower is 8~10C lower than ambient and the pressure gauge blue line (Low P side), NEVER touch 0C. Touch 0C for that amount of gas means your evaporator is frozen with ice lor - May damage evaporator and not cold as the effective surface area is reduced - You get a feeling like the air is damp and cold lor.

 

OK.

 

Gas need to be in the exact amount in grammes. My new carens need 550g of R134A. So how to know you have 550g ? Either do very detailed measurement of the supercool state of the aircon vs pressure OR empty all gas, top up gas with a weighing machine lor.

 

So troublesome, no need to top better. Only my first car, I kuku don't know, top until die lor.

 

OK,

 

Aircon Oil, also need to be exact one. I also never top what oil one lor. Does it matter the mechanic top up 15~20CC of oil ??

You ONLY need to top up oil when you CHANGE AIRCON component. For every car, you can get a table for it one. For example, if you change Discharge pipe, you need to top up 20CC of Oil for a Kia Carens III (UN), change evaporator add 50CC, change compressor another volume one. Usually or always, change compressor no need to add oil because the manufacturer would have added for you.

 

Too much oil, not cold. Too little oil, compressor die.

 

So how, No Change No Add best.

 

OK

 

Vacuum Pump, How long to evac air ? 45mins, the vac pump need to run for AT LEAST 45mins to suck as much as air as possible. Not 5~15mins OK, no pressure and start adding gas.

 

Why suck for 45 mins when after 5~mins the low pressure reach the lowest point ? Because water kill aircon too, when under low pressure water become a gases state lor. And it is a very slow process, especially water in dryer.

 

OK

 

How to detect leak ? You can actually add about 20~30CC of fluorescent oil into your aircon lor. If there is a leak, use a UV touchlight you can detect where is the leak lor. Very popular in US and Europe as owner like to ownself detect first then look for mechanic lor.

 

Good aircon don't leak, if it leak, usually need to change something. If anyhow top up, most probably ownself damage aircon due to over pressure lor.

 

OK.

Usually aircon not cold is radiator fan not running properly due to connector issue lor.

 

 

Go youtube, a lot of channel on auto aircon repair and detection.

 

Good luck.

Thanks! Bro you really professional. May I know are you in aircon business? I want give you service. Haha

 

I noticed in SG or MY 80% of mechanics scam you. Even AD there was once a Korean brand aircon AD send 1 guy to me but he smoke and smoke full of lies and said the whole industry also like that. Not happy I next time don’t buy. Very poor ethics

[Apple-Tree]

I actually ownself repair my car aircon 2 years ago.

 

And all the screwup I have encountered.  Simply, I have enough.  

 

 

http://www.mycarforum.com/topic/2699312-advice-needed-on-car-aircon/?p=5881874

 

 

Thanks! Bro you really professional. May I know are you in aircon business? I want give you service. Haha

I noticed in SG or MY 80% of mechanics scam you. Even AD there was once a Korean brand aircon AD send 1 guy to me but he smoke and smoke full of lies and said the whole industry also like that. Not happy I next time don’t buy. Very poor ethics

 

[Evillusion]

I actually ownself repair my car aircon 2 years ago.

 

And all the screwup I have encountered. Simply, I have enough.

 

 

http://www.mycarforum.com/topic/2699312-advice-needed-on-car-aircon/?p=5881874

sometime aircon suddenly blows warm air because the engine is overheating.....i kana a few times. Not sure what has overheating got to do with aircon. First time kana was due to insufficient coolant in radiator. Later kana again due to my relay box for the radiator fan had burnt at the contacts.

[Apple-Tree]

Yup, always start repair or go get mechanics or whatever, start with simple and cheap and easy to repair stuff.  Like Radiator Fan connector, check if it is oxidized or corroded, just change it and see how.

 

In my case, the evaporator kuput, at first just want to get the compressor replace lor.

 

I am just sharing with you so that you have a choice or at least in the know on what to do lor ....

 

 

Rather than let mechanic talk until got dragon got tiger lor ....

 

 

sometime aircon suddenly blows warm air because the engine is overheating.....i kana a few times. Not sure what has overheating got to do with aircon. First time kana was due to insufficient coolant in radiator. Later kana again due to my relay box for the radiator fan had burnt at the contacts.

 

[Mkl22]

sometime aircon suddenly blows warm air because the engine is overheating.....i kana a few times. Not sure what has overheating got to do with aircon. First time kana was due to insufficient coolant in radiator. Later kana again due to my relay box for the radiator fan had burnt at the contacts.

The only reason is the radiator fan has stopped turning. No air flow to both the radiator and Aircon condenser so both are hot.

[Evillusion]

Yup, always start repair or go get mechanics or whatever, start with simple and cheap and easy to repair stuff. Like Radiator Fan connector, check if it is oxidized or corroded, just change it and see how.

 

In my case, the evaporator kuput, at first just want to get the compressor replace lor.

 

I am just sharing with you so that you have a choice or at least in the know on what to do lor ....

 

 

Rather than let mechanic talk until got dragon got tiger lor ....

thats what mechanics will do......make you spend money. Good thread this as aircon is rather handy in our hot and humid climate. Last i had my aircon blowing hot air was when my main gasket failed. Hot weather engine will overheat in traffic light or jam. When jb for a top overhaul and now everything is good.

The only reason is the radiator fan has stopped turning. No air flow uto both the radiator and Aircon condenser so both are hot.

ya...thought so too but some pips were rather sceptical. Thanks for the tip.

[smoothtalker]

I actually ownself repair my car aircon 2 years ago.

 

And all the screwup I have encountered. Simply, I have enough.

 

 

http://www.mycarforum.com/topic/2699312-advice-needed-on-car-aircon/?p=5881874

Wow! Respect you bro. I am the type like to hands on and fix my own things too. Still learning the basics of car. My challenge now is hard to find technical manuals and the exploded chat listing each part and part number. Need to learn.

[Sosaria]

Could be bah, I read somewhere Mazada parts quite ex. Anyway, quite easy to find out since u oredi knows the parts to be changed & gauged from there, inclusive labour charge.

 

Yes, we can expect AD parts to be quite expensive. But then we are paying for new parts and with warranty. Having drove nissan and mazda and comparing AD repairs ... mazda is on the higher side. Luckily i not driving conti, else major     

 

Came upon this thread because aircon repaired recently. Suddenly while driving, the fan went to full blast, and subsequently only blowing hot air. AD check, told me hose leaked and compressor need to change. So      6+ year car. 

[kopfan]

Yes, we can expect AD parts to be quite expensive. But then we are paying for new parts and with warranty. Having drove nissan and mazda and comparing AD repairs ... mazda is on the higher side. Luckily i not driving conti, else major

 

Came upon this thread because aircon repaired recently. Suddenly while driving, the fan went to full blast, and subsequently only blowing hot air. AD check, told me hose leaked and compressor need to change. So 6+ year car.

This sound so familiar...

I experienced the hot air at the 9th year of my car... Very common issue to experience old weak compressor and valve leak due to wear and tear. The good thing, driving without AC, can get at least additional 150km mileage on a full tank.

[Vinz]

Anyone experience roaring or humming noise around gloves box area when air con is running?? Noise was intermittent but its not normal.. My ride toyota allion. Thks

[Apple-Tree]

Ever got noise coming from the blower.  That is after I pull out the filter to air jet it.

 

When I pull out, it is full of small small leaf (rain tree leaves) lor.  I know something sure fell into the blower.

 

Intermittent noise.

 

Took out the filter again, a week later and air jet the blower, some leave flew out and problem solved.

 

Your case could be debris like mine or a bad blower.  Start simple and free then see if problem solve lor.

 

Anyone experience roaring or humming noise around gloves box area when air con is running?? Noise was intermittent but its not normal.. My ride toyota allion. Thks

 

[awhtc]

Anyone experience roaring or humming noise around gloves box area when air con is running?? Noise was intermittent but its not normal.. My ride toyota allion. Thks

Fan bearing could be worn out.

[Vinz]

Fan bearing could be worn out.

 

Fan bearing ?  Noise is intermittent and only when speed is low and after engine is hot....noise seem to be near the centre console or glove box. was suspecting compressor clutch bearing. Annoying trying to pin point the actual source  

[Evillusion]

Correct, my aircon suddenly not cold intermittently. Went to first fraudster mechanic near my work place check and anyhow claim need to change both compressor and condenser for $1200+. I straight away run.

 

Went to another more reliable 'recommend by friend' mechanic and they found out actually radiator overheat with radiator cap purging coolant below which they showed me. Top-up coolant for test and later found radiator hose fitting leak, replaced hose set and aircon back to freezing cold.

 

But this mechanic is only half-honest. Because they also try to get some money by claiming my compressor going to spoil soon as the low pressure meter is stuck at 60psi and didn't go below. But high pressure is good at about 200-230 psi.

 

Later I went online to check youtube videos on how to read low/high pressure and release the SOP is need to rev engine then the Low pressure will drop to about 40-55 psi (good for local SG daytime ambient of about 30 Deg) after connection and setting temp to lowest, 75% fan etc.

 

So I went to 3rd workshop (supposed to be aircon specialist at Toh Guan road) and go straight to look at low gauge after they connect. The mechanic (JHK as usual) maybe realized I seem to know how to see the aircon pressure, then proceed to carry out the proper SOP and rev the engine etc.

 

True enough, the low pressure drop from 50+ psi to below 40 psi. and my high pressure side is good at around 220 psi. Then at first he says there is nothing wrong with my aircon and can use.

 

But again later he touched the freon pipes at bonnet and claim my pipes don't seemed cold enough and can be colder further by doing 'Aircon Recovery", which is something like vacuum and gas replacement. But I decline, saying I don't have time.

 

I know its nonsense because my aircon is freezing cold when I set to just 25 deg, whether in morning or hot weather and need to eventually up to 26 deg C.

 

Conclusion is, its true that about 80% of all mechanics are dishonest. For the remaining 20%, 80% are selective in their honesty which depends on whether they have enough sales for the month, LOL.

 

Like the bible says, there is non righteous on earth. All eventually become fraudster once they gain you trust, which is even worst. LOL

Thats a very good learning experience......i also learnt to troubleshoot problem from youtube first then go to ws to do the necessary. Nowadays cant trust the ws 100%....they are there to maximise their profit.