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


Reply
 
Thread Tools Search this Thread
Old 16th March 2009, 13:27   #1
BHPian
 
Join Date: Dec 2007
Location: mumbai
Posts: 285
Thanked: 16 Times
Default Zen AC problem

Hello everybody,
Yesterday a strange thing happen to my AC, I was driving towards Raigad and had kept my AC on MAX ( I drive Zen LXI 2002, MPFI).After driving for about 3 hrs, the AC starting giving hot air, stopped to have a look, first it looked OK for me, compressor was working fine, then pressed the AC button two to three times and check the gas for bubbles( I have read on this forum that when you start your AC bubbles are seen initially when you see through the small glass provided)well the bubbles were missing and I had given up on my AC, later after 15 mim I again started my AC just to check, and yes it started to give cold air so much so that we were freezing. This continued for rest of my journey, while returning back again the same thing happen, and after switching off for 15 min it started.

Now my question, what would be the problem? All the great brains I require your inputs before I give my car for service.
udaydesai is offline   Reply With Quote
Old 16th March 2009, 13:47   #2
BHPian
 
kannan666's Avatar
 
Join Date: Aug 2007
Location: KA-02
Posts: 939
Thanked: 69 Times
Default

Can think of a few things to check, here goes...

1, Check that the switch which regulates both hot and cold air is working properly and is not getting stuck or moved about.

2. It could be that since you had the setting for cooling (thermostat) at maximum, sometimes the unit freezes and no air can then pass through the unit resulting in no cooling. It works fine again after some time as the unit thaws out (icing melts). This has happened to me in my 800 a couple of times before I could get the exact setting for the thermostat.

3. Check the system for the correct quantum of A/C gas (refrigent). This can be done only at the workshop.
kannan666 is offline   Reply With Quote
Old 16th March 2009, 13:49   #3
Senior - BHPian
 
Join Date: Sep 2007
Location: New Delhi
Posts: 3,083
Thanked: 252 Times
Default

Quote:
Originally Posted by udaydesai View Post
stopped to have a look, first it looked OK for me, compressor was working fine, then pressed the AC button two to three times and check the gas for bubbles( I have read on this forum that when you start your AC bubbles are seen initially when you see through the small glass provided)well the bubbles were missing and I had given up on my AC, later after 15 mim I again started my AC just to check, and yes it started to give cold air so much so that we were freezing.
Uday, seems like there is moisture in the gas and it causes the expansion valve to freeze up, or get 'iced up', thus blocking all gas flow totally!
You'd have to get your AC connected to the charging station and have the gas passed through a filter/dryer to rectify this problem.
But they'll all recommend that you get the system vacuumed and put in a fresh charge of gas! They earn more that way, LOL!
anupmathur is offline   Reply With Quote
Old 16th March 2009, 13:52   #4
BHPian
 
Mr_Bean's Avatar
 
Join Date: Nov 2008
Location: Bangalore
Posts: 842
Thanked: 128 Times
Default

I too faced with same problem with my esteem carb, while driving from chennai to Bangalore the AC started pumping out hot air. I was maintaining a speed of 100 km/hr in fifth gear.

This is what MASS had to say " Sir, the temperature outside is hot & that is why the AC is pumping hot air" ..
Mr_Bean is offline   Reply With Quote
Old 16th March 2009, 14:02   #5
BHPian
 
Join Date: Dec 2007
Location: mumbai
Posts: 285
Thanked: 16 Times
Default

Quote:
Originally Posted by anupmathur View Post
Uday, seems like there is moisture in the gas and it causes the expansion valve to freeze up, or get 'iced up', thus blocking all gas flow totally!
You'd have to get your AC connected to the charging station and have the gas passed through a filter/dryer to rectify this problem.
But they'll all recommend that you get the system vacuumed and put in a fresh charge of gas! They earn more that way, LOL!
thx for your advice. But how could moisture have entered my system.
udaydesai is offline   Reply With Quote
Old 16th March 2009, 15:10   #6
Senior - BHPian
 
Join Date: Sep 2007
Location: New Delhi
Posts: 3,083
Thanked: 252 Times
Default

Quote:
Originally Posted by udaydesai View Post
But how could moisture have entered my system.
LOL, Uday, not your system! I clearly said the car's gas system!

Hard to say precisely but usually moisture gets in if there has been occasion for the compressor to have gone into negative suction pressure for some duration.
Most commonly it happens during gas charging or topping up.
anupmathur is offline   Reply With Quote
Old 16th March 2009, 16:05   #7
BHPian
 
Join Date: Dec 2007
Location: mumbai
Posts: 285
Thanked: 16 Times
Default

Quote:
Originally Posted by Mr_Bean View Post
I too faced with same problem with my esteem carb, while driving from chennai to Bangalore the AC started pumping out hot air. I was maintaining a speed of 100 km/hr in fifth gear.

This is what MASS had to say " Sir, the temperature outside is hot & that is why the AC is pumping hot air" ..
but then have you faced this problem again. Cannot trust MASS
udaydesai is offline   Reply With Quote
Old 16th March 2009, 19:01   #8
BHPian
 
Perakath's Avatar
 
Join Date: Feb 2009
Location: Chennai
Posts: 259
Thanked: 28 Times
Default

Quote:
Originally Posted by udaydesai View Post
After driving for about 3 hrs, the AC starting giving hot air
A couple of times I've accidentally moved the thermostat lever from cold to hot when what I meant to do was move the air intake lever from recirculated to fresh air! (They're parallel to each other in the Zen.) Just couldn't figure out why the a/c wasn't cooling at all
Perakath is offline   Reply With Quote
Old 16th March 2009, 19:42   #9
BHPian
 
anurag_p80's Avatar
 
Join Date: Dec 2007
Location: Hyderabad
Posts: 313
Thanked: 7 Times
Default

Seems like a ice formation problem. It shouldn't throw out hot air though, just the cooling will reduce. If you are running continuously on recirculation mode, try letting in fresh air once in a while (turn recirculate off). Try switching the compressor off for sometime, for the ice to melt, and it should cool again (just like happened with you). Check this thread where a few solutions are discussed.
http://www.team-bhp.com/forum/techni...-problems.html (Fiat Palio MJD - Known Problems)
anurag_p80 is offline   Reply With Quote
Old 16th March 2009, 19:58   #10
BHPian
 
Mr_Bean's Avatar
 
Join Date: Nov 2008
Location: Bangalore
Posts: 842
Thanked: 128 Times
Default

Quote:
Originally Posted by udaydesai View Post
but then have you faced this problem again. Cannot trust MASS
uday, my AC gas was re-filled & since then I am just not happy with the working of the AC, It has happened to me many times in peak traffic and once on highway. But does the blower fan have anything to do this problem.

Refilling the gas is little high, it come to 900-1000/- rupees.
Mr_Bean is offline   Reply With Quote
Old 17th March 2009, 00:31   #11
Senior - BHPian
 
Join Date: Sep 2006
Location: zxc
Posts: 3,394
Thanked: 658 Times
Default

@ anup! dryer is already in the system. The one has the glass window is the dryer.

Two things.
1. relay, check for loose. if so use WD40 on terminals.
2. expansion valve. can be set, but is an expert job, as it lies way inside the coil. So if mechianic is an expert he will repair this without releasing the gas. Or you will end up paying unnecessarily for the refill.
SirAlec is offline   Reply With Quote
Old 17th March 2009, 07:50   #12
Senior - BHPian
 
Join Date: Sep 2007
Location: New Delhi
Posts: 3,083
Thanked: 252 Times
Default

Quote:
Originally Posted by SirAlec View Post
@ anup! dryer is already in the system. The one has the glass window is the dryer.
I thought it was merely an accumulator and/or a vapour trap.
Even if it has a dryer, the hygroscopic material has been 'used up', or is saturated with moisture. The symptoms described are typical of exp valve icing up.
anupmathur is offline   Reply With Quote
Old 17th March 2009, 09:54   #13
Team-BHP Support
 
Jaggu's Avatar
 
Join Date: May 2004
Location: Bangalore
Posts: 17,746
Thanked: 7,449 Times
Default

Quote:
Originally Posted by anupmathur View Post
I thought it was merely an accumulator and/or a vapour trap.
Even if it has a dryer, the hygroscopic material has been 'used up', or is saturated with moisture. The symptoms described are typical of exp valve icing up.
Yup this is classic case of icing up, visit to a good car ac mech can set it right, usually happens when ac is running for long and might not show up if used for short while. So double check once the job is completed.
Jaggu is offline   Reply With Quote
Old 17th March 2009, 09:54   #14
BHPian
 
Join Date: Dec 2007
Location: mumbai
Posts: 285
Thanked: 16 Times
Default

Quote:
Originally Posted by Mr_Bean View Post
uday, my AC gas was re-filled & since then I am just not happy with the working of the AC, It has happened to me many times in peak traffic and once on highway. But does the blower fan have anything to do this problem.

Refilling the gas is little high, it come to 900-1000/- rupees.
my a/c compressor had been serviced by my trusted mechanic in the month of oct last year,after that my a/c was cooling was great. After that i did goa trip where the a/c was on for 3 days why no ice formation had taken then? I had this car for 3 years now never had this problem before. How come now ice is forming?
udaydesai is offline   Reply With Quote
Old 17th March 2009, 10:07   #15
Senior - BHPian
 
Join Date: Sep 2007
Location: New Delhi
Posts: 3,083
Thanked: 252 Times
Default

Uday, have you had the gas topped up or compressor oil topped up?
Moisture gets into an AC system through these routes.
Once there is the slightest bit of moisture, it can cause partial icing up in the expansion valve. This in turn can create a negative suction pressure in the compressor at times, for short durations. This allows atmospheric air to be sucked in, carrying more moisture. The problem gets aggravated.

Anyhow, does it matter? You've described a problem. It is almost certainly moisture related.
That's the best anyone can tell you sitting miles away!
anupmathur 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
S-Zen?(Swift engine in a Zen) raghuram.cg Modifications & Accessories 14 21st September 2008 10:52
99'ZEN carb to ZEN mpfi.... Balram Modifications & Accessories 17 10th December 2006 09:04
No more ZEN for Zen Lovers abhibh The Indian Car Scene 65 8th May 2006 17:17
Used Zen vs new Zen shuvc Hatchbacks 12 18th August 2005 19:16
E-Zen & B-Zen.... MustangMan The Indian Car Scene 3 2nd July 2005 21:27


All times are GMT +5.5. The time now is 02:51.

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