Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 21st July 2006, 20:53   #1
Senior - BHPian
 
kutlee's Avatar
 
Join Date: Jul 2005
Location: Hyderabad
Posts: 1,126
Thanked: 194 Times
Default 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.
kutlee is offline   Reply With Quote
Old 21st July 2006, 23:02   #2
Senior - BHPian
 
Join Date: May 2005
Location: Hyderabad
Posts: 1,099
Thanked: 157 Times
Default

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)
Buffetfan is offline   Reply With Quote
Old 22nd July 2006, 00:38   #3
BHPian
 
prasadee's Avatar
 
Join Date: Apr 2005
Location: San Diego
Posts: 564
Thanked: 246 Times
Default

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!!
prasadee is offline   Reply With Quote
Old 22nd July 2006, 03:01   #4
Senior - BHPian
 
Join Date: May 2005
Location: Hyderabad
Posts: 1,099
Thanked: 157 Times
Default

yes.. it is funny.. I said it in a lighter vain though I am perplexed about this useless design
Buffetfan is offline   Reply With Quote
Old 22nd July 2006, 07:02   #5
Distinguished - BHPian
 
jkdas's Avatar
 
Join Date: Sep 2005
Location: Thiruvananthapu
Posts: 9,661
Thanked: 1,389 Times
Default

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?
jkdas is offline   Reply With Quote
Old 22nd July 2006, 08:49   #6
ECM
BHPian
 
ECM's Avatar
 
Join Date: May 2006
Location: Somewhere
Posts: 221
Thanked: 6 Times
Default

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.
ECM is offline   Reply With Quote
Old 22nd July 2006, 08:54   #7
Team-BHP Support
 
tsk1979's Avatar
 
Join Date: Feb 2005
Location: New Delhi
Posts: 22,953
Thanked: 15,648 Times
Default

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.
tsk1979 is offline   Reply With Quote
Old 22nd July 2006, 11:00   #8
Senior - BHPian
 
kutlee's Avatar
 
Join Date: Jul 2005
Location: Hyderabad
Posts: 1,126
Thanked: 194 Times
Default

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?
kutlee is offline   Reply With Quote
Old 22nd July 2006, 11:23   #9
BANNED
 
viper's Avatar
 
Join Date: Mar 2005
Location: Mumbai
Posts: 1,769
Thanked: 8 Times
Default

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
viper is offline   Reply With Quote
Old 22nd July 2006, 14:09   #10
Senior - BHPian
 
Join Date: Jul 2004
Location: Madurai
Posts: 1,006
Thanked: 645 Times
Default

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?
jyobeb is offline   Reply With Quote
Old 22nd July 2006, 16:04   #11
BANNED
 
viper's Avatar
 
Join Date: Mar 2005
Location: Mumbai
Posts: 1,769
Thanked: 8 Times
Default

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
viper is offline   Reply With Quote
Old 25th August 2009, 19:14   #12
Senior - BHPian
 
deky's Avatar
 
Join Date: Jul 2008
Location: Jaipur
Posts: 1,192
Thanked: 1,029 Times
Default

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?
deky is offline   Reply With Quote
Old 25th August 2009, 21:06   #13
jav
BHPian
 
Join Date: Apr 2007
Location: Bangalore
Posts: 194
Thanked: 6 Times
Default

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.
jav is offline   Reply With Quote
Old 25th August 2009, 21:13   #14
Senior - BHPian
 
abhibh's Avatar
 
Join Date: Sep 2005
Location: Back in the HOOD near you!
Posts: 2,767
Thanked: 33 Times
Default

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.
abhibh is offline   Reply With Quote
Old 25th August 2009, 21:56   #15
Senior - BHPian
 
Join Date: Sep 2006
Location: zxc
Posts: 3,394
Thanked: 658 Times
Default

change the settings on the expansion valve. if found faulty replace.
SirAlec is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Long drives on my swift..left knee pain rajshenoy Technical Stuff 32 31st October 2012 22:33
How do front wheel drives and Rear wheel drives behave in a skid adrian Technical Stuff 10 29th June 2011 17:51
Esteem VXi '05 - My New Ride!! Update @ 80K Kms with a long drives & track day pics Venom_rider Long-Term Ownership Reviews 37 25th February 2011 03:47
Zen - Engine Switching off on long drives Tiger Technical Stuff 10 11th January 2008 10:28
Car or Motorcycle - for long, cross country drives ? GS300 Street Experiences 20 21st May 2006 21:37


All times are GMT +5.5. The time now is 00:26.

Copyright 2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks