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


Reply
 
Thread Tools Search this Thread
Old 5th April 2015, 16:34   #1
BHPian
 
90Horses's Avatar
 
Join Date: May 2014
Location: Bangalore
Posts: 108
Thanked: 37 Times
Angry Air-con: Center vents throwing out warmer air than side vents?

My car is Punto 90Hp bought from Vecto Fiat Bangalore in the month of December 2013. My Punto was a great car until its 1st Year service which happened at a mileage of 12000 Kms. Later that from 14K onward, the HVAC was faulty. I have mentioned the problem in detail along with the service history in the below link from page 30 onwards.

http://www.team-bhp.com/forum/techni...-punto-30.html (Some quality niggles & Issues in Fiat Punto)

Problem:
The passenger side Central AC vent throws warm/less-cool air than other AC vents. Except that vent, all other vents are working alike. I did all experiments, but this behavior was consistent. Vent temperature difference was about 5~7 degrees. This degree variation is found when temperature was set to >24 C. As a result, the car does not cool down, you will feel chill on your front side and drenched with sweat on your back, long drives will make your condition worse.

Investigation from FIAT started on 19-Feb-2015, initially they told me no such issue exists with the car, later after comparing the vent temperature with other cars, they got into a conclusion that an issue exists. In my attempt to resolve the issue, I drove the car 5 times to Vecto Fiat, which was 25 Kms from my place. From 19th February to now Vecto Fiat replaced High Pressure, Low pressure AC pipes and HVAC unit, still issue is not fixed yet, now they are guessing Compressor .

I doubt the quality of the car, it has been mere 1 Year of ownership and 16K on the ODO, now car is sitting duck in dealership as FIAT does not understand why my car behaves in this way and does not understand itís loyal customerís pain.

My takeaways from Vecto Fiatís/FIATís diagnosis:
One word - Sloppy. FIAT & Vecto Fiat communicate over emails, dealer sends his investigation report to FIAT tech team and they respond, this chain of events go on and on until both come to a common understanding. They do not understand customerís pain and suffering, I am a FIAT fan and I do not deserve this. I have demanded FIAT engineers to come and see my car in person, but it did not work out.

It has been a month and a half, but FIAT could not know where the issue in the car is, all they did is to change the parts without proper investigation. I strongly believe, no one in the dealership had own this problem, they are just wasting their and my time. Moreover, replacing so many parts in a new car is simply outrageous. I thought to take matters in my own hands and diagnose by my own and provide my findings to FIAT.

My diagnosis:
I believe issue could be with the actuator flaps that control the hot/cold air mixture. So my theory is the actuator that controls the passenger central vent has gone kaput and it is stuck at a point where it allows more hot air and does not respond to ACCís input. Please see the youtube link ​.

If high-low pressure pipes, HVAC or compressor fails, the cooling system in the whole will not work. If evaporator coil fails then I would get hot air in all vents. But in my car, only 1 vent is throwing less cool/warm air.

It would be great if you folks could help me diagnosing better and resolve this peculiar issue with my car and put a stop to my sufferings.

Thanks,
Sai
90Horses is offline   (1) Thanks Reply With Quote
Old 5th April 2015, 18:20   #2
Distinguished - BHPian
 
dhanushs's Avatar
 
Join Date: Oct 2009
Location: Bathery/BLR
Posts: 3,445
Thanked: 4,054 Times
Default re: Air-con: Center vents throwing out warmer air than side vents?

Quote:
Originally Posted by 90Horses View Post
My diagnosis:
I believe issue could be with the actuator flaps that control the hot/cold air mixture. So my theory is the actuator that controls the passenger central vent has gone kaput and it is stuck at a point where it allows more hot air and does not respond to ACC’s input.
IMO, your diagnosis is correct.

I have a friend who's Thar has had the exact same issue, and it still has. Whenever you come back from from hot setting to cold setting, the driver side vents starts acting up. However, in the Thar, turning the knob few times back anf forth, does the trick, and he hasn't visited the service center (Well, there's no point ).

Please ask the A.S.S guys to sort out the diverter valve issue.
dhanushs is offline   (2) Thanks Reply With Quote
Old 5th April 2015, 21:12   #3
BHPian
 
90Horses's Avatar
 
Join Date: May 2014
Location: Bangalore
Posts: 108
Thanked: 37 Times
Default re: Air-con: Center vents throwing out warmer air than side vents?

Quote:
Originally Posted by dhanushs View Post
Please ask the A.S.S guys to sort out the diverter valve issue.
Thanks for your insight dhanushs. I have updated Vecto Fiat CRM about this finding, will see how much they would understand and fix the issue. I will keep the thread updated.
90Horses is offline   Reply With Quote
Old 6th April 2015, 02:22   #4
BHPian
 
VCheng's Avatar
 
Join Date: Jan 2011
Location: New York
Posts: 175
Thanked: 245 Times
Default re: Air-con: Center vents throwing out warmer air than side vents?

Your diagnosis is along the correct lines. It may be the actuator(s), or the flap(s) itself which could have corroded hinges or disintegrated insulation along its edges that allow leaks. The problem will be finding the parts, otherwise the whole subassembly may need to be changed.
VCheng is offline   (2) Thanks Reply With Quote
Old 6th April 2015, 05:51   #5
Senior - BHPian
 
Join Date: Apr 2008
Location: Dombivli
Posts: 2,626
Thanked: 1,191 Times
Default re: Air-con: Center vents throwing out warmer air than side vents?

Why don't you imitiate a written correspondence with the dealer as well as Fiat India? They might move faster if they realize you are building a case for delay in repairs and faulty diagnosis resulting in the car becoming unusable. Do consult a lawyer practising in a consumer court, if you can.
honeybee is offline   Reply With Quote
Old 6th April 2015, 06:04   #6
Senior - BHPian
 
rajeev k's Avatar
 
Join Date: Jul 2009
Location: Emerging Metro
Posts: 3,306
Thanked: 1,730 Times
Default re: Air-con: Center vents throwing out warmer air than side vents?

Show your car at another Service Center and inform about your diagnosis. Perhaps, someone there with gray matter would be able to sort the issue out.
rajeev k is offline   Reply With Quote
Old 6th April 2015, 09:38   #7
BHPian
 
90Horses's Avatar
 
Join Date: May 2014
Location: Bangalore
Posts: 108
Thanked: 37 Times
Default

Quote:
Originally Posted by VCheng View Post
Your diagnosis is along the correct lines. It may be the actuator(s), or the flap(s) itself which could have corroded hinges or disintegrated insulation along its edges that allow leaks. The problem will be finding the parts, otherwise the whole subassembly may need to be changed.
Thank you VCheng, it is good to know that my investigation is on right line. Until now FIAT has replaced parts without proper investigation. I will coordinate with them to make sure this time they change the right part. Customer is fixing his car's problem, sounds funny.




Quote:
Originally Posted by honeybee View Post
Why don't you imitiate a written correspondence with the dealer as well as Fiat India? They might move faster if they realize you are building a case for delay in repairs and faulty diagnosis resulting in the car becoming unusable. Do consult a lawyer practising in a consumer court, if you can.

Thanks honeybee, I have kept this option as my last. They are doing the job, but it is not upto customer's satisfaction. I have got their attention and I hope they would solve my case. I will see for few weeks on how they proceed and take action accordingly.




Quote:
Originally Posted by rajeev k View Post
Show your car at another Service Center and inform about your diagnosis. Perhaps, someone there with gray matter would be able to sort the issue out.
Thanks rajeev, in blr fiat has 3 service centers, Vecto Fiat have the best service men. From 2 months case is with them, if i go to another service center then it could take more time and effort, which i am unwilling to spend.
90Horses is offline   Reply With Quote
Old 7th April 2015, 11:35   #8
BHPian
 
90Horses's Avatar
 
Join Date: May 2014
Location: Bangalore
Posts: 108
Thanked: 37 Times
Default Re: Air-con: Center vents throwing out warmer air than side vents?

Quote:
Originally Posted by dhanushs View Post
Please ask the A.S.S guys to sort out the diverter valve issue.
Quote:
Originally Posted by VCheng View Post
Your diagnosis is along the correct lines. It may be the actuator(s), or the flap(s) itself which could have corroded hinges or disintegrated insulation along its edges that allow leaks. The problem will be finding the parts, otherwise the whole subassembly may need to be changed.
Guys, yesterday I visited Vecto Fiat and had a discussion with Service Executives and Divisional Manager. They have shown me the replaced HVAC unit, it was huge and it had actuators, evaporator, blower and other components bundled into one unit.

They have expected the issue to get resolved after replacing the HVAC unit, but unfortunately it did not happen. So, the chances of issue with HVAC unit is ruled out, they are now concentrating on Compressor, Condenser and pipes connecting them. I have demanded to get the FIAT engineers on board, if none of their diagnosis yield positive results, they have agreed on that.

I will keep you posted.

-Sai
90Horses is offline   Reply With Quote
Old 7th April 2015, 12:23   #9
Senior - BHPian
 
Captain Slow's Avatar
 
Join Date: Mar 2010
Location: Bangalore
Posts: 1,256
Thanked: 649 Times
Default Re: Air-con: Center vents throwing out warmer air than side vents?

Quote:
Originally Posted by 90Horses View Post
Guys, yesterday I visited Vecto Fiat and had a discussion with Service Executives and Divisional Manager. They have shown me the replaced HVAC unit, it was huge and it had actuators, evaporator, blower and other components bundled into one unit.

They have expected the issue to get resolved after replacing the HVAC unit, but unfortunately it did not happen. So, the chances of issue with HVAC unit is ruled out, they are now concentrating on Compressor, Condenser and pipes connecting them. I have demanded to get the FIAT engineers on board, if none of their diagnosis yield positive results, they have agreed on that.

I will keep you posted.

-Sai

Was a leak test very done?
You have a pressure leak somewhere in the Aircon system.
This issue is related to the low pressure aircon pipe. The one that runs between the evaporator coil and the compressor.
Captain Slow is offline   (1) Thanks Reply With Quote
Old 7th April 2015, 14:03   #10
BHPian
 
90Horses's Avatar
 
Join Date: May 2014
Location: Bangalore
Posts: 108
Thanked: 37 Times
Default Re: Air-con: Center vents throwing out warmer air than side vents?

Quote:
Originally Posted by Captain Slow View Post
Was a leak test very done?
You have a pressure leak somewhere in the Aircon system.
This issue is related to the low pressure aircon pipe. The one that runs between the evaporator coil and the compressor.
Thanks for your insight. The high & low pressure pipes that go from condenser to expansion valve were replaced, but issue was not solved. As you have rightly pointed out, the pressure pipes between expansion valve - compressor and condenser are the suspected culprits.

Yesterday, they have replaced high & low pressure pipes between expansion valve and compressor, I am yet to know the results. They are doing a trail and error by replacing these parts one by one from the dealer's car, hope I will get to know which part was the culprit.
90Horses is offline   Reply With Quote
Old 7th April 2015, 14:38   #11
Senior - BHPian
 
sandeepmohan's Avatar
 
Join Date: Feb 2010
Location: Wellington
Posts: 1,938
Thanked: 1,616 Times
Default Re: Air-con: Center vents throwing out warmer air than side vents?

The flaps should work based on instruction sent from a sensor in the car, that is linked to the automatic climate control. If the sensor is kaput or isn't able to detect with accuracy, the car's cabin temperature may not be stable nor will it operate the flaps, thermostat properly. I am not a car air conditioning expert. I think it is best to try and replace the front control unit of the automatic climate control with another car's unit and check. If you notice, there is a tiny vent on the control unit. I do not know about its function but there must be a reason why it is there. It is worth a try as this should be more a plug and play thing than dealing with something a lot more complex like a compressor unit.

I drive a Fiat Linea and have observed the exact same thing on my car. However; it all depends on the temperature setting combined with ambient temperature. Well past sunset or early morning, 23-24 degree setting is sufficient. At this setting, my car behaves exactly as yours. I don't find it a fault. The central ducts blow lukewarm air and the side vents blow cold air after a certain period of the aircon operating. I feel this is being done to maintain the set temperature. When I fire up the aircon, hitting the star button on the right side of the control unit (I don't use full auto), air direction set to Face only, all vents throw cold air, blower operates at a high speed initially and gradually drops as set cabin temperature is reached. After this, I have observed lukewarm air from the central vents. This won't be the case though if the car has been out, parked in the sun. Even at 24-25 degree, all vents are blowing cold air, all the time as it does take a lot longer to cool the cabin.

I am wondering if you really have a problem or if the system is working as it should.

Try a lower setting such as <23 degrees and see what happens.

Last edited by sandeepmohan : 7th April 2015 at 14:39.
sandeepmohan is offline   Reply With Quote
Old 7th April 2015, 15:32   #12
Distinguished - BHPian
 
Join Date: Oct 2012
Location: Delhi
Posts: 3,056
Thanked: 6,171 Times
Default Re: Air-con: Center vents throwing out warmer air than side vents?

Reading through all of this I can understand your frustration. My initial thought, based on similar experience would have been as per your original diagnosis. These mechanism do fail occosianaly. The suggestion made by Sandeepmohan about the various sensors and it might work as advertised should not be ruled out.

The fact that Fiat cant trouble shoot this is more trouble some, because it should not be so difficult. Those that follow my posts will know I'm a huge advocate of diagnosing first before replacing.

Here is what I think should have done;

To Sandeepmohan's point, first make absolutely sure, you understand how the AC system, ventilating and all of the various knobs and levers are supposed to work. Unfortunately it might not be as straightforward as you would hope or expect. The only way to do so is to take the owner manual and go through it line by line of instructions and observe if you are getting the right response (i.e. cool and warm air) from the various ducts and openings at the appropiate settings.

If that all works out well:
The OBD systeem of your Fiat has a whole bunch of codes related to the working of the AC. (At least western variant do. So the first thing, alwasy, hook it up to an OBD analyser and see if it throws out any error codes. If it does, that would be your first port of call.

If there are no codes, I would proceed as follows:

Based on the symptons you describe I cant think why anything would be the matter with the AC System itself, ie the compressor, condensor, valves etc. It does provide cool air, just not where you want it.

So you still need to figure out if the various valves open and close appropiately. A properly kitted out workshop migh have a little endoscoop they can stick into the various airducts to see what goes on. (e.g. something like this https://www.machinemart.co.uk/shop/p...s-inspection-c )

If they dont have one, I would try and have the complete HVAC unit hooked up to the car, but try and remove the various air ducts. You want to try and see the various actuaros/flap and so move, open, close. that might give further indication what goes on.

Good luck and let us know what they find.

Jeroen

Last edited by Jeroen : 7th April 2015 at 15:33.
Jeroen is online now   (1) Thanks Reply With Quote
Old 7th April 2015, 16:55   #13
BHPian
 
90Horses's Avatar
 
Join Date: May 2014
Location: Bangalore
Posts: 108
Thanked: 37 Times
Default Re: Air-con: Center vents throwing out warmer air than side vents?

Quote:
Originally Posted by sandeepmohan View Post
The flaps should work based on instruction sent from a sensor in the car, that is linked to the automatic climate control. If the sensor is kaput or isn't able to detect with accuracy, the car's cabin temperature may not be stable nor will it operate the flaps, thermostat properly. I am not a car air conditioning expert. I think it is best to try and replace the front control unit of the automatic climate control with another car's unit and check. If you notice, there is a tiny vent on the control unit. I do not know about its function but there must be a reason why it is there. It is worth a try as this should be more a plug and play thing than dealing with something a lot more complex like a compressor unit.

I drive a Fiat Linea and have observed the exact same thing on my car. However; it all depends on the temperature setting combined with ambient temperature. Well past sunset or early morning, 23-24 degree setting is sufficient. At this setting, my car behaves exactly as yours. I don't find it a fault. The central ducts blow lukewarm air and the side vents blow cold air after a certain period of the aircon operating. I feel this is being done to maintain the set temperature. When I fire up the aircon, hitting the star button on the right side of the control unit (I don't use full auto), air direction set to Face only, all vents throw cold air, blower operates at a high speed initially and gradually drops as set cabin temperature is reached. After this, I have observed lukewarm air from the central vents. This won't be the case though if the car has been out, parked in the sun. Even at 24-25 degree, all vents are blowing cold air, all the time as it does take a lot longer to cool the cabin.

I am wondering if you really have a problem or if the system is working as it should.

Try a lower setting such as <23 degrees and see what happens.
My car has this problem always at all times of day. The temperature difference from both central vents was noted as 7 degrees. Usually in all linea and punto it is 1-2 degrees. HVAC unit was replaced under warranty, still this problem was not rectified. Before this issue, my car was a chiller. With this problem, even if I set 21 degrees, with left central vent does not throw cool air, its taking a lot time than usual to cool the car, making me sweaty.

Yes problem exists, other Punto's & Linea's vent temperatures are compared to my car with every test they do.
90Horses is offline   Reply With Quote
Old 7th April 2015, 17:14   #14
Senior - BHPian
 
sagarpadaki's Avatar
 
Join Date: May 2010
Location: Bengaluru
Posts: 2,632
Thanked: 1,256 Times
Default Re: Air-con: Center vents throwing out warmer air than side vents?

Quote:
Originally Posted by 90Horses View Post
My car has this problem always at all times of day. The temperature difference from both central vents was noted as 7 degrees. Usually in all linea and punto it is 1-2 degrees. HVAC unit was replaced under warranty, still this problem was not rectified. Before this issue, my car was a chiller. With this problem, even if I set 21 degrees, with left central vent does not throw cool air, its taking a lot time than usual to cool the car, making me sweaty.

Yes problem exists, other Punto's & Linea's vent temperatures are compared to my car with every test they do.
Does punto/linea not have a mechanism/slider switch which will block the air coming from that particular vent? If the vent has that option keep it closed till the problem is rectified. At least it will solve the sweating problem
sagarpadaki is offline   Reply With Quote
Old 7th April 2015, 18:25   #15
BHPian
 
VCheng's Avatar
 
Join Date: Jan 2011
Location: New York
Posts: 175
Thanked: 245 Times
Default Re: Air-con: Center vents throwing out warmer air than side vents?

Quote:
Originally Posted by 90Horses View Post
Guys, yesterday I visited Vecto Fiat and had a discussion with Service Executives and Divisional Manager. They have shown me the replaced HVAC unit, it was huge and it had actuators, evaporator, blower and other components bundled into one unit.

They have expected the issue to get resolved after replacing the HVAC unit, but unfortunately it did not happen. So, the chances of issue with HVAC unit is ruled out, they are now concentrating on Compressor, Condenser and pipes connecting them. I have demanded to get the FIAT engineers on board, if none of their diagnosis yield positive results, they have agreed on that.

I will keep you posted.

-Sai
Okay, now it is getting interesting.

Let us step back. Has anyone actually put in a thermometer in the different vents to see the actual readings of the air coming out with AC at full blast?
VCheng 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
DIY: Rear Air-Con Vents wanderernomad DIY - Do it yourself 73 23rd February 2015 10:17
Odd sound from Air-con vents mvaidy Technical Stuff 15 19th January 2015 07:45
Mid Range in A/C Side vents ? Mi10 In-Car Entertainment 3 7th December 2010 09:15
Hot air vents out under the dash of my alto! please help sunil.nv Technical Stuff 7 26th February 2009 10:54


All times are GMT +5.5. The time now is 01:28.

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