A/C problem in Santro on long drives

kutlee · 21st July 2006, 20:53

Hi,
I normally use my Santro for city drives. So won't last for more than hour typically. I have noticed a peculiar problem on long drives. Last time i drove for about 4 hours. after the first hour or so, the a/c effect gradually decreased. i have no problem in city drives. i usually switch it on/off every now and then since it gets too cold inside. i travel in mornings and evenings. on the drive, after i noticed the problem, i checked the a/c blower area with my hand and felt the air flow to be very low, eventhough i can feel it to be cold. also there is difference in noise from the blower with the gradual reduction in a/c effect. i switched it off and after a few minutes turned it on. it was working perfect. again after some time the same problem. on hot sunny days, i can't afford to switch it off for 1 minute even. i don't know what the problem is. is ice being formed in the evaporator area and blocking the air to flow though the coil fins or something like that? why does it work when i swith on/off frequently? is the ice getting melted and clear way for the air?

PS : the technical stuff i quoted are from my basic refreigiration knowledge

Lee.

Buffetfan · 21st July 2006, 23:02

I hate the Santro AC.. not as good as any of the Marutis.... also what I dont understand is the basic lack of insulation in the AC gas inlet pipe... nearly one meter of pipe leading to the evap grill in teh engine compartment is not insulated... it becomes ice cold in the engine compartment and (thereby helps cool the engine I guess :((( ) and reduces the AC efficiency in the cabin..
plan to get it insulated this time I give it for servicing (1st service at 1k kms)

prasadee · 22nd July 2006, 00:38

Quote:

Originally Posted by Buffetfan

nearly one meter of pipe leading to the evap grill in teh engine compartment is not insulated... it becomes ice cold in the engine compartment and (thereby helps cool the engine I guess :((( )

Thats funny! The AC itself is powered by the engine, and if someone designs a car with the AC cooling the engine, all I can say is that he is way too smart!!

Buffetfan · 22nd July 2006, 03:01

yes.. it is funny.. I said it in a lighter vain though I am perplexed about this useless design

jkdas · 22nd July 2006, 07:02

Quote:

Originally Posted by Buffetfan

I hate the Santro AC.. not as good as any of the Marutis.... also what I dont understand is the basic lack of insulation in the AC gas inlet pipe... nearly one meter of pipe leading to the evap grill in teh engine compartment is not insulated... it becomes ice cold in the engine compartment and (thereby helps cool the engine I guess :((( ) and reduces the AC efficiency in the cabin..
plan to get it insulated this time I give it for servicing (1st service at 1k kms)

can someone confirm/decode/enlighten abt this?

ECM · 22nd July 2006, 08:49

Very interesting indeed and I was unaware of this design in Santro AC.Though I never owned Santro in my life but I have seen one of my friend using Santro since long time.Only plus side of Santro I found that it is far better than Maruti WagonR when sound effect goes(!!)yes all WagonR gives us sound effects while running(internal noises like glass channel,door noise,shock absorber/strut noise etc..)but I love Santro in this subject as its hinges,Glass channels,jumpers/struts are far better designed than WagonR...slightly off topic though.

tsk1979 · 22nd July 2006, 08:54

If you are driving in the city in hot afternoon and you dont switch of the AC, does this problem come?
This looks like the AC is heating up and =shutting down for short periods. There could be several reasons for this
1. Engine overheating. When engine overheats, the AC cuts of to prevent damage. Sometimes its a faulty temp sensor which is telling the control unit that engine is overheating, when it isnt. Also check your engine fan and also when efficency decreases, where is the temp needle
2. Condenser fan. If the condenser fan of AC is not working properly, i.e. randomly running at lower rpm due to motor fault, this could be cause of the problem
3. AC idler.

kutlee · 22nd July 2006, 11:00

Quote:

Originally Posted by tsk1979

If you are driving in the city in hot afternoon and you dont switch of the AC, does this problem come?
This looks like the AC is heating up and =shutting down for short periods. There could be several reasons for this
1. Engine overheating. When engine overheats, the AC cuts of to prevent damage. Sometimes its a faulty temp sensor which is telling the control unit that engine is overheating, when it isnt. Also check your engine fan and also when efficency decreases, where is the temp needle
2. Condenser fan. If the condenser fan of AC is not working properly, i.e. randomly running at lower rpm due to motor fault, this could be cause of the problem
3. AC idler.

I went today to Talwar service center. service told the condenser might have chocked. Then i asked that in that case how will it work initially. it doesn't get chocked in the first half hour!!. I asked is there a problem with evaporator which is actually cooling the air. then the guy told you are right sir. he told that only way out is to clean the whole a/c system @ 3000rs. i think the guy just wants to make some money instead of pinning the problem out. i agree that there might be some clogging at the evaporator part. but in that case how does it work wonderfully in the first half hour or so? there is something related to time which actually aggrevates the problem. it can be a sensor, fan motor etc. i admired the a/c of santro. Can i check out the options1,2,3 at home by any means?
I have a question. if there is anything faulty with temp sensor, engine overload etc which cuts off the a/c system, how does it block the air flow? the airflow should be the same with no cooling. i suspect ice formation at the evaporator area. but that should be drained of continuously by design. can anyone help me?

viper · 22nd July 2006, 11:23

Quote:

Originally Posted by kutlee

i suspect ice formation at the evaporator area. but that should be drained of continuously by design. can anyone help me?

Hi,

that can easily be checked. When you do experience this problem just pull over and open the hood. Put your hand on the ac pipe and if it is chilled you have your answer. If your car is new then this may be the problem if not check your expansion valve.

If the problem is ICE formation you can solve it 2 ways.

1> Reduce the amount of gas in the system.
2> Reduce the thermostat a bit to a warmer setting.

Your problem should be solved. BTW a complete AC service which includes flushing the system for a santro including gas top up etc should not cost you more than RS1750/- max. Any parts to be changed extra.

Hope I have been of some help.

Viper

jyobeb · 22nd July 2006, 14:09

You actually answered your own question. The evaporator coils seem to be icing up and blocking air flow. Viper has given you the solution. However Viper, is,nt there a pressure valve that senses low pressure and cuts off the compressor? So will that option work?

viper · 22nd July 2006, 16:04

Quote:

Originally Posted by jyobeb

YHowever Viper, is,nt there a pressure valve that senses low pressure and cuts off the compressor? So will that option work?

Hi,

I suggested release some gas not all of it. There is actually a switch that will prevent the compressor from starting in the absence of gas or very little gas to prevent compresssor damage.

Viper

deky · 25th August 2009, 19:14

Sorry to be phishing out an old thread but can someone help me regarding the same problem, like the thread starter, I am experiencing with The AC of my car.

City driving is not an issue as usually the drive is not longer than 45 mnts or so. But the problem arises when we out on highways. Initially the for say 1st hr, the cooling is perfect but after that the cooling starts to lessen and even the air flow from the vents reduces. After 1.30hrs of driving the cooling is absolutely nill. But when i stopped the car and started after 20 mnts or so the AC was back to normal. I could notice a pool of water on the road below the engine, which I guess was the water that melted from the frozen pipes.

The first time i experinced this, it was an early morning drive so I guess it could be the cooler weather that could have frozen the pipes even more. But the second time it happened the outside temperature was almost 40 degrees. I was amazed that it happened in hot weather too.

Is the soloution same as what some guys have mentioned above?

Is there something more to it than excess of gas in the condenser?

Dont the cars have a thermostat which cuts of after reaching certain temperatures thus avoiding jamming of pipes?

jav · 25th August 2009, 21:06

This is mostly caused by a faulty thermostat which does not cut off when the temperature drops or can be blockage of the coils as mentioned in the above posts, Get it checked by a good A/C mechanic or service center.

abhibh · 25th August 2009, 21:13

I have the same problem in my Alto. In city drives or idling the AC wont shut off even for 2 hours, but on highways after every hour i had to turn off the blower for 10 mins and start it again.

It been 2 - 3 weeks since i have had this problem.

SirAlec · 25th August 2009, 21:56

change the settings on the expansion valve. if found faulty replace.

21st July 2006, 20:53	#1
kutlee Senior - BHPian Join Date: Jul 2005 Location: Hyderabad Posts: 1,141 Thanked: 232 Times View My Garage	A/C problem in Santro on long drives Hi, I normally use my Santro for city drives. So won't last for more than hour typically. I have noticed a peculiar problem on long drives. Last time i drove for about 4 hours. after the first hour or so, the a/c effect gradually decreased. i have no problem in city drives. i usually switch it on/off every now and then since it gets too cold inside. i travel in mornings and evenings. on the drive, after i noticed the problem, i checked the a/c blower area with my hand and felt the air flow to be very low, eventhough i can feel it to be cold. also there is difference in noise from the blower with the gradual reduction in a/c effect. i switched it off and after a few minutes turned it on. it was working perfect. again after some time the same problem. on hot sunny days, i can't afford to switch it off for 1 minute even. i don't know what the problem is. is ice being formed in the evaporator area and blocking the air to flow though the coil fins or something like that? why does it work when i swith on/off frequently? is the ice getting melted and clear way for the air? PS : the technical stuff i quoted are from my basic refreigiration knowledge Lee.
	() Thanks

21st July 2006, 23:02	#2
Buffetfan Senior - BHPian Join Date: May 2005 Location: Hyderabad Posts: 1,130 Thanked: 203 Times	I hate the Santro AC.. not as good as any of the Marutis.... also what I dont understand is the basic lack of insulation in the AC gas inlet pipe... nearly one meter of pipe leading to the evap grill in teh engine compartment is not insulated... it becomes ice cold in the engine compartment and (thereby helps cool the engine I guess :((( ) and reduces the AC efficiency in the cabin.. plan to get it insulated this time I give it for servicing (1st service at 1k kms)
	() Thanks

22nd July 2006, 03:01	#4
Buffetfan Senior - BHPian Join Date: May 2005 Location: Hyderabad Posts: 1,130 Thanked: 203 Times	yes.. it is funny.. I said it in a lighter vain though I am perplexed about this useless design
	() Thanks

22nd July 2006, 08:49	#6
ECM BHPian Join Date: May 2006 Location: Somewhere Posts: 226 Thanked: 16 Times	Very interesting indeed and I was unaware of this design in Santro AC.Though I never owned Santro in my life but I have seen one of my friend using Santro since long time.Only plus side of Santro I found that it is far better than Maruti WagonR when sound effect goes(!!)yes all WagonR gives us sound effects while running(internal noises like glass channel,door noise,shock absorber/strut noise etc..)but I love Santro in this subject as its hinges,Glass channels,jumpers/struts are far better designed than WagonR...slightly off topic though.
	() Thanks

22nd July 2006, 08:54	#7
tsk1979 Team-BHP Support Join Date: Feb 2005 Location: San Jose, CA Posts: 23,725 Thanked: 23,053 Times View My Garage	If you are driving in the city in hot afternoon and you dont switch of the AC, does this problem come? This looks like the AC is heating up and =shutting down for short periods. There could be several reasons for this 1. Engine overheating. When engine overheats, the AC cuts of to prevent damage. Sometimes its a faulty temp sensor which is telling the control unit that engine is overheating, when it isnt. Also check your engine fan and also when efficency decreases, where is the temp needle 2. Condenser fan. If the condenser fan of AC is not working properly, i.e. randomly running at lower rpm due to motor fault, this could be cause of the problem 3. AC idler.
	() Thanks

22nd July 2006, 14:09	#10
jyobeb Senior - BHPian Join Date: Jul 2004 Location: Madurai Posts: 1,010 Thanked: 704 Times	You actually answered your own question. The evaporator coils seem to be icing up and blocking air flow. Viper has given you the solution. However Viper, is,nt there a pressure valve that senses low pressure and cuts off the compressor? So will that option work?
	() Thanks

25th August 2009, 19:14	#12
deky Senior - BHPian Join Date: Jul 2008 Location: Jaipur Posts: 1,194 Thanked: 1,251 Times	Sorry to be phishing out an old thread but can someone help me regarding the same problem, like the thread starter, I am experiencing with The AC of my car. City driving is not an issue as usually the drive is not longer than 45 mnts or so. But the problem arises when we out on highways. Initially the for say 1st hr, the cooling is perfect but after that the cooling starts to lessen and even the air flow from the vents reduces. After 1.30hrs of driving the cooling is absolutely nill. But when i stopped the car and started after 20 mnts or so the AC was back to normal. I could notice a pool of water on the road below the engine, which I guess was the water that melted from the frozen pipes. The first time i experinced this, it was an early morning drive so I guess it could be the cooler weather that could have frozen the pipes even more. But the second time it happened the outside temperature was almost 40 degrees. I was amazed that it happened in hot weather too. Is the soloution same as what some guys have mentioned above? Is there something more to it than excess of gas in the condenser? Dont the cars have a thermostat which cuts of after reaching certain temperatures thus avoiding jamming of pipes?
	() Thanks

25th August 2009, 21:06	#13
jav BHPian Join Date: Apr 2007 Location: Bangalore Posts: 224 Thanked: 66 Times	This is mostly caused by a faulty thermostat which does not cut off when the temperature drops or can be blockage of the coils as mentioned in the above posts, Get it checked by a good A/C mechanic or service center. Last edited by jav : 25th August 2009 at 21:15.
	() Thanks

25th August 2009, 21:13	#14
abhibh Senior - BHPian Join Date: Sep 2005 Location: Back in the HOOD near you! Posts: 2,769 Thanked: 39 Times	I have the same problem in my Alto. In city drives or idling the AC wont shut off even for 2 hours, but on highways after every hour i had to turn off the blower for 10 mins and start it again. It been 2 - 3 weeks since i have had this problem.
	() Thanks

25th August 2009, 21:56	#15
SirAlec Senior - BHPian Join Date: Sep 2006 Location: zxc Posts: 3,395 Thanked: 727 Times	change the settings on the expansion valve. if found faulty replace.
	() Thanks