I have a chevy optra ,and on a long journey ,say Pattaya to BKK the air con slowely gets less effective ,after switching it off for about 15 minutes it starts working again , any ideas? ive had it checked ,cleaned the filter ect ,nothing out of the ordinary , but just cant seem to find an answer,so any help would be appreciated.

You might try setting the Temp lower to about 65%,, and the Fan on 45-50 %. Make shure the Kids dont mess with the Windows. I smoke and drive sometimes,so i just turn the compessor off.If not i get youre prob.

When you said you had it checked did they have to do anything, like gassing it up.?

If its the Evap core freezing up there "should" be a drop in airflow speed out the vents, if not then there may be some other problem, is there a rise in coolant temperature around the same time as it drops performance?

If its the Evap core freezing up there "should" be a drop in airflow speed out the vents, if not then there may be some other problem, is there a rise in coolant temperature around the same time as it drops performance?

just a drop in airflow speed and not as cold ,also my coolant was fine ,they could find no problem

When you said you had it checked did they have to do anything, like gassing it up.?

nothing it was fine.

on a long journey ,say Pattaya to BKK the air con slowely gets less effective

experienced something like this many years ago. it drove me mad as all tests showed nothing wrong. turned out that the compressor clutch was slipping and generating heat which made it slip even more. car was a Porsche 911 with a "dedicated" slip when the engine turned above 5,500 rpm. to correct the problem only a small adjustment was required.

addendum: in my case there was no ice at the evaporator.

Had similar problem.

Turned out the generator was retiring.

Had similar problem.

Turned out the generator was retiring.

About as relevant as a Flat Battery.

Had similar problem.

Turned out the generator was retiring.

About as relevant as a Flat Battery.

It is relevant if the volts arent high enough to keep the compressor clutch engaged or the condenser fan at its normal speed.

Had similar problem.

Turned out the generator was retiring.

About as relevant as a Flat Battery.

It is relevant if the volts arent high enough to keep the compressor clutch engaged or the condenser fan at its normal speed.

Yes but if you take that line eventually one could say its out of fuel. Its not Rocket Science.More likely something simple.These Air Guys are generally dam good.

Had similar problem.

Turned out the generator was retiring.

About as relevant as a Flat Battery.

It is relevant if the volts arent high enough to keep the compressor clutch engaged or the condenser fan at its normal speed.

Yes but if you take that line eventually one could say its out of fuel. Its not Rocket Science.More likely something simple.These Air Guys are generally dam good.

I have seen them work on my car now, 2 compressors later and they still wont replace the orings like i requested that are causing the leaks that are causing the compressor to fail. I think they just dont want to fix things so they keep getting work.

Had similar problem.

Turned out the generator was retiring.

About as relevant as a Flat Battery.

It is relevant if the volts arent high enough to keep the compressor clutch engaged or the condenser fan at its normal speed.

That's not likely to happen in the middle of a long trip when the "alternator" (haven't had generators for about 40 years or more) is putting out maximum voltage. It is more likely to happen when the engine is idling for long periods and not up to maximum rpm's producing maximum charge and the A/C is at peak requirement in heavy traffic....

Had the same problem with my Vigo If The aircon: was set on internal/cabin flow only, cure turn it onto outside to inside for a few min's: or the cooler control to down about half. It was iceing up. Had had it checked by Toyota report nothing wrong. I found the problem when setting fan to high speed there was icy smoke coming out of the vent's big time. Even more if I had had the window open for a short time, while I had a ciggy.

Had the same problem with my Vigo If The aircon: was set on internal/cabin flow only, cure turn it onto outside to inside for a few min's: or the cooler control to down about half. It was iceing up. Had had it checked by Toyota report nothing wrong. I found the problem when setting fan to high speed there was icy smoke coming out of the vent's big time. Even more if I had had the window open for a short time, while I had a ciggy.

Yes, I was going to suggest opening the vent to bring some hotter outside air through the evaporator but got sidetracked..

I'm rather amazed the no one has suggested the the system is overcharged. The simple test is to place a thermometer in the discharge vent. The temperature of the air coming out should be well above freezing. If the outlet temperature is too low, the humidity will freeze on the evaporator and you will end up with no cooling and your evaporator will end up being a block of ice. And yes, I had that problem. Mine leaked water all over the floor.

I suppose we have all been there, picked the Village Idiot to fix it,left a window down a little.I know a place where they still do the Old Gas Recharge,its colder,the Owner Drivers of Hinos, etc no them too, and its cheaper..

Sorry haven't read all the replies but don't dismiss a thermostat failure on the aircon system or a temperature sensor covered with something. Had a ride with two sensors, one in the roof and one on the top of the dash that were not noticeable.

Sorry haven't read all the replies but don't dismiss a thermostat failure on the aircon system or a temperature sensor covered with something. Had a ride with two sensors, one in the roof and one on the top of the dash that were not noticeable.

Excellent Point. But i would guess you had Air Conditioning, not just "Fridge" as Americans call a basic system as is most common here. A big difference.

Sorry haven't read all the replies but don't dismiss a thermostat failure on the aircon system or a temperature sensor covered with something. Had a ride with two sensors, one in the roof and one on the top of the dash that were not noticeable.

Excellent Point. But i would guess you had Air Conditioning, not just "Fridge" as Americans call a basic system as is most common here. A big difference.

Don't understand your point.

Sorry haven't read all the replies but don't dismiss a thermostat failure on the aircon system or a temperature sensor covered with something. Had a ride with two sensors, one in the roof and one on the top of the dash that were not noticeable.

Excellent Point. But i would guess you had Air Conditioning, not just "Fridge" as Americans call a basic system as is most common here. A big difference.

Don't understand your point.

Climate Conroll is a different issue if it goes wrong, there are many sensors,A Lincon Town Car with a Glass Division, for example,would be harder to fix than a Jazz. The Sprinter Trains never been fixed since its first run here.

Sorry haven't read all the replies but don't dismiss a thermostat failure on the aircon system or a temperature sensor covered with something. Had a ride with two sensors, one in the roof and one on the top of the dash that were not noticeable.

Excellent Point. But i would guess you had Air Conditioning, not just "Fridge" as Americans call a basic system as is most common here. A big difference.

Don't understand your point.

Climate Control is a different issue if it goes wrong, there are many sensors,A Lincoln Town Car with a Glass Division, for example,would be harder to fix than a Jazz. The Sprinter Trains never been fixed since its first run here.

Not a yank so..........

Have a friend with the same car and same problem, they replaced the compressor and that fixed it. Hate to say it but that car is a turd, many problems and he bought it new.

Have a friend with the same car and same problem, they replaced the compressor and that fixed it. Hate to say it but that car is a turd, many problems and he bought it new.

Hes not alone,why they buy them is beyond me when theres Toyo and Honda.Its a Korean Based Cheapy with a Chevy Badge

Have a friend with the same car and same problem, they replaced the compressor and that fixed it. Hate to say it but that car is a turd, many problems and he bought it new.

Hes not alone,why they buy them is beyond me when theres Toyo and Honda.Its a Korean Based Cheapy with a Chevy Badge

Absolute rubbish,i have had the car now for five years ,from new ,its been terrific, never had any problems and it drives and still looks like new ,by the way its made in Rayong,not Korea.

Have a friend with the same car and same problem, they replaced the compressor and that fixed it. Hate to say it but that car is a turd, many problems and he bought it new.

Hes not alone,why they buy them is beyond me when theres Toyo and Honda.Its a Korean Based Cheapy with a Chevy Badge

Absolute rubbish,i have had the car now for five years ,from new ,its been terrific, never had any problems and it drives and still looks like new ,by the way its made in Rayong,not Korea.

Luckey You, but my Neighbours Wife, says the same as Thunder, it is a first Re Badge before Rayong admitedly,shes cant afford to change.its Second Hand with long re payments, she cold have been better advised.So ill stick by my Comment.

as far as testing the AC, one of these little thermometers placed in the center duct

should be reading 50-60 F outlet temps. is the system adequately charged/undercharged/

overcharged? well a manifold gauge set connected to both the high side and low sides

of the system will tell you that. also is the compressor cycling on/off often

because the pressure switch is shutting it off or a mechanical problem with clutch?

there are ways of checking for leaks in the system? draw down a vaccuum with said type

pump and then close system and see if it will maintain vaccuum. use a dye along with

refridgerant/oil and minute leaks will oftens show themselves. i mean what i'm saying is

you can approach it with a scientific method. crossing items off your list until you

arrive at the culprit. and comparing it with other similar make/model is a good idea. on the older systems (and probably true even today) there was an "expansion valve" at inlet of evaporator core. this, along with a "sensing bulb" would control the flow of refridgerant. so begin with measuring outlet duct temps so you have and actual number range, not just "a feeling". then you can attempt to isolate a probable cause. and find your discrepancy.

^ Thats the correct way to diagnose the ac system def.

Have a friend with the same car and same problem, they replaced the compressor and that fixed it. Hate to say it but that car is a turd, many problems and he bought it new.

Hes not alone,why they buy them is beyond me when theres Toyo and Honda.Its a Korean Based Cheapy with a Chevy Badge

Absolute rubbish,i have had the car now for five years ,from new ,its been terrific, never had any problems and it drives and still looks like new ,by the way its made in Rayong,not Korea.

Luckey You, but my Neighbours Wife, says the same as Thunder, it is a first Re Badge before Rayong admitedly,shes cant afford to change.its Second Hand with long re payments, she cold have been better advised.So ill stick by my Comment.

So what your saying is that its a different car to what i have ,its an old model made in Korea that she has ,unlike a newer model made in Rayong like i have ?

ever heard of Skoda ,the old style and the new one ,different cars same name.

i should have said "electro-magnetic clutch" with manual adjustment. if you have someone else turn the air on.

while standing alongside the engine bay and observing the compressor. you will hear a loud "clack" as the clutch

engages, and also see the compressor start to turn, as part of the clutch remains stationary when not

engaged. per the 911 porsche example, often these cars were gray-market overseas versions with AC installed

after leaving factory. the clearance between contact surfaces is adjustable with shims (usually) if incorrect

you will have slippage and an inefficiently functioning system. also today i believe they have refridgerant

sniffer testers to detect escaping gas. it's not always an easy thing to diagnose problems with these systems.

it's not unheard of to have problems with new cars leaving manufacturing plant that have nothing to do with

the vehicle operator, or age, or anything that could be described as normal re a maintenance schedule. and i'm

certainly no authority. cars are so difficult today you almost have to specialize in one specific make.