[pixantz]

Originally Posted by pkulkarni.2106

The radiator has been replaced just a year back, so we can rule that out. Also, the engine did never overheat.

Overheat doesn't always mean totally coolant-spewing-steaming situation. Sometimes it partially overheats and there is a point where the Ac cuts off. Just should be sure when it cuts off that the temp needle is not higher than it should be. Even a little bit.

Originally Posted by pkulkarni.2106

My car also has this habit of cutting the AC off every now and then. I was anyway looking for a reason for that behavior, and no mechanic gave me satisfactory reason/diagnosis till now.

Ok, now this a different scenario. If the Ac cuts of "every now and then", it is a different set of possible causes. Like:
1)Weak/faulty compressor clutch electromagnet coil. This guy when faulty overheats prematurely and disengages the compressor at erratic intervals hence stopping cooling.

2) faulty compressor relay getting overheated causing cut off

3) overcharge of refrigerant which causes a high pressure situation in the system and subsequent cut off problem.

4) loose wiring electrical glitch

5) faulty evaporator core sensor causing cut off

6) inadequate air flow of condenser fan due to various reasons

7) wrong direction of air flow of condenser fan due to improper wiring

8 ) radiator and condenser touching each other physically.


These are the most probable causes but a proper hands on diagnosis is the best way to pin point the devil or as they say, "ghost in the machine" .

[Jeroen]

Originally Posted by pixantz

Firstly about the drop in cooling after 5-6 hours, I think if a properly working Ac stops properly cooling when the car has run for a considerable time that most probably points to the fact that, at that point of performance drop, your car ecm is cutting of the Ac and the only reason it would do that is that your car engine is overheating at that point. The first precaution the car takes on engine overheat situation is shutting off the Ac. It won't let the Ac turn on again until your engine is at safe temperature levels. So the problem is possibly with the cars engine cooling system/s. Not the Ac.
.

It is correct that most AC’s will be shut down if the engine cooling liquid is reaching too high a temperature.

I am not sure if that is the case here. Why only after 5-6 hours. Long duration driving does not necessarily lead to higher engine temperatures. If your car has issues with its cooling system it will show up on short drives as well. In particular city, bumper to bumper driving. High way cruising is rarely a problem as the engine and radiator are getting a lot of cooling from the drive wind.

If the car overheats, or shuts down the AC during city driving, long period of idling in the blazing heat, I would suspect the cooling system of the car.

Is the problem occurring only after prolonged motorway driving and you spend the last half hour of every journey in slow, start/stop traffic? That might be a giveaway.

Just because the radiator has been replaced is no guarantee. Why was is replaced? If somebody filled it up with water rather than undistllled water/cooling liquid it will clog up very quickly. Dirt, leaves can accumulate very quickly on radiators, what about the thermostat, the fan, and the condition of the hoses?

Jeroen

[H_Dogg72]

Would like to know should I get ac gas refilled in my polo which is 4+ years old and has never got anything ac related done apart from cabin filter changes every 4 months and a bit of disinfecting here and there.
Reason I ask is, it's the coldest ac in the house, yet the oldest car. Don't fix if it ain't broke?

[hserus]

Originally Posted by H_Dogg72

Would like to know should I get ac gas refilled in my polo which is 4+ years old and has never got anything ac related done apart from cabin filter changes every 4 months and a bit of disinfecting here and there.
Reason I ask is, it's the coldest ac in the house, yet the oldest car. Don't fix if it ain't broke?

If the AC cooling is satisfactory don't touch it.

[interc00led]

Originally Posted by pkulkarni.2106

OK, here I am again with the question regarding my Santro's AC.
This is observed while doing long highway trips. While starting the trip, AC performs quite well.
5-6 hours into the journey (typically when I'm close to my destination), the cooling drops considerably.


What could be the issue for both these cases?

The evaporator coil is clogged up with dirt and it's icing up on highways due to less airflow.
Get the coil cleaned.

[pixantz]

Originally Posted by Jeroen

Why only after 5-6 hours. Long duration driving does not necessarily lead to higher engine temperatures. If your car has issues with its cooling system it will show up on short drives as well.

He has said that OTHERWISE the Ac is working properly. So if a properly working Ac cuts of erratically it points to engine overheat.

Originally Posted by Jeroen

Is the problem occurring only after prolonged motorway driving and you spend the last half hour of every journey in slow, start/stop traffic? That might be a giveaway.

Jeroen

What I thought too. See, we can only speculate according to what has been reported. There could be inaccuracies in the reporting which would change the whole diagnosis. That's why I have also stressed on physical diagnosis for the real cause/s. We an sit in remote places and berate all day long on what MIGHT be wrong. Mr Puranik has later reported that it actually happens "every now and then" for which I have later given him completely different causes. I hope that clears it. Cheers.

Originally Posted by interc00led

The evaporator coil is clogged up with dirt and it's icing up on highways due to less airflow.
Get the coil cleaned.

That might have been a cause but the person has not reported mist coming out of the cooling vents and subsequently slowly reducing blower speeds which is a symptom of icing.

It's hard to pinpoint without a hands-on physical diagnosis as I have explained above. Sometimes many symptoms are either missed or not reported.

[JayKavadi]

I own a Honda City 2012 model. I recently went on a drive to Nasik from Mumbai and found the Air conditioning to be inadequate. It needs to be mentioned here that the temperature outside was a bit high (around 38-39 degress) and I started the drive late morning around 9. The cooling was fine initially but as we drove beyond the first 40-45 kms, the cooling started dropping progressively. As a trial and error approach, i switched off the AC for 10 odd minutes and drove with windows rolled down slightly. After this when I switched the AC on, it started cooling better but again for just 15-20 minutes. Again the cooling started to drop. I continued with this for the remainder of the journey. Also one more thing I noticed was that on my way back, once i hit city limits and the speeds dropped to usual city speeds (< 75-80), the cooling seemed to improve.

In terms of AC maintenance specifically, I had last got it serviced with Unicool in Ghatkopar, Mumbai in May last year. He had hosed down the entire radiator (after removing the front bumper) and then topped up the AC gas. Since then, Ive never had any complaints but then I never drove it out of Mumbai.

Would really appreciate any inputs as to what the possible causes of this are

[ruzbehxyz]

When I start my car AC, usually seconds after starting the car, there is a weird smell (not foul odour / rat attack etc). However this smell goes off within a minute and AC runs fine. This issue started after I got my AC filter cleaned. There is no issue in the AC running or cooling. Vehicle is Ford Endeavour and two years old. Could it be that the filter is placed upside down or is it some other issue ? Any inputs are appreciated.

[hserus]

Originally Posted by ruzbehxyz

When I start my car AC, usually seconds after starting the car, there is a weird smell (not foul odour / rat attack etc). However this smell goes off within a minute and AC runs fine. This issue started after I got my AC filter cleaned. There is no issue in the AC running or cooling. Vehicle is Ford Endeavour and two years old. Could it be that the filter is placed upside down or is it some other issue ? Any inputs are appreciated.

You sure you aren't smelling ac gas?

Don't clean the ac filter, replace it every 5k or so kilometers.

[ruzbehxyz]

Originally Posted by hserus

You sure you aren't smelling ac gas?

Don't clean the ac filter, replace it every 5k or so kilometers.

It's not AC gas. Its just a weird smell. Can't explain it. My service is due next month so will definitely get the filter changed. However till then I was think of a solution.

[sgiitk]

Originally Posted by interc00led

The evaporator coil is clogged up with dirt and it's icing up on highways due to less airflow.
Get the coil cleaned.

A nice pressure wash of the condenser and radiator often does wonders. I had this situation in my Zen and was flummoxed. This is what worked. I was told that much more than the evaporator this is often required. Then I recalled once the front end of my car was treated by the 'dump' of a cow.

[guptavis]

Hi all,

I have a maruti Alto Lx 2007 which has done 82K Kms.
Whenever i switch on the AC there is a screeching noise for a few seconds and then it goes away. I thought it was the 'AC belt'. Went to the ASS and my suscpicion was confirmed and it was said that AC belt needs to be changed (though it is not frayed).

Price of the belt was mentioned at Rs.360. However, the ASS did not have it in stock. They said they've already placed an order and will get it in a week.
It looked like it was seated deep in the engine bay and may need some components to be taken off from the engine bay. I want to know if this is a simple job that a roadside mechanic can take care of or does it require special skill. Can i buy the belt from an MGP store and let a roadside mecahanic install it or is it safer to let an ASS work on it?

If a roadside mechanic can do it, is it the kind of mechanic I give it to for engine oil + filter change or the kind of people who do AC service and fill AC 'gas'.
Asking so much cause every mechanic ive met here claims to know everything and never turns down any job. one chap i asked to replace the spark plugs and he was trying to remove the bolts on the engine head!!

[subbu567]

Fellow BHP’ians

Need an advice for a friend - who has a corolla world car sedan 2015 vintage, recently he hit a pot hole and had the tyre sheared and replaced - now the AC compressor which seems to sit right above seems to have cracked and TOYOTA is asking him to replace with a tab of 30-32 K. Is there a way to restore it by brazing and a gas refill? If yes, any one in Bangalore would you recommend ? He is a fellow car worshipper by the way but in general an ‘off line’ man!

Thanks for the help.

Subbu.

[Rshrey22]

Originally Posted by subbu567

Fellow BHP’ians

Need an advice for a friend - who has a corolla world car sedan 2015 vintage, recently he hit a pot hole and had the tyre sheared and replaced - now the AC compressor which seems to sit right above seems to have cracked and TOYOTA is asking him to replace with a tab of 30-32 K. Is there a way to restore it by brazing and a gas refill? If yes, any one in Bangalore would you recommend ? He is a fellow car worshipper by the way but in general an ‘off line’ man!

Thanks for the help.

Subbu.

Try finding a refurbished unit in the market otherwise a new Subross compressor is something that you can source for 15k easily. Then you can get it fitted from outside. It'll be 17-18k for the total work + parts.

[arindambasu13]

The AC on my Honda Brio has stopped working. That is, while the air flow remains constant, there is no cooling taking place. The car is due for its annual service and I plan to give it for service in the next few days. Typically, what could be the issue? Mechanical failure of the condenser etc, or is it more likely that the AC gas needs a top up?

If it is a mechanical failure, what kind of replacement/ repair cost am I looking at, approximately?

Any views would be appreciated.