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


Reply
 
Thread Tools Search this Thread
Old 29th November 2011, 12:35   #1
BHPian
 
TaurusAl's Avatar
 
Join Date: Mar 2011
Location: Mumbai - MH 01
Posts: 521
Thanked: 315 Times
Default Air-con compressor in a diesel car does not trip?

I own a Ritz VDI and this is my first diesel car. Initially i owned a Santro petrol and Wagon R petrol. I used to notice that whenever I kept the blower on 1 or 2 position, the compressor used to cut-off automatically. I'm sure this has a positive effect on mileage too.

But off-late i have noticed that the A/c of my Diesel Ritz does not trip even when the blower is on 1 position. I took the car to the service station, and the service person confirmed that the A/c does not trip in diesel vehicles as opposed to petrol.

Can the experts please comment if this is true and in this case, is there any point in keeping the blower on minimum to improve the FE ?
TaurusAl is offline   Reply With Quote
Old 29th November 2011, 13:33   #2
BHPian
 
mtnrajdeep's Avatar
 
Join Date: Feb 2006
Location: Bangalore
Posts: 648
Thanked: 88 Times
Default Re: Air condition in a diesel Car does not trip

Yes, in the Swift and Ritz diesels, the compressor does not trip. Found this out when my car was a year old and got it checked from the service center in Bangalore. They confirmed that this does not happen for diesel vehicles. The only use of keeping the blower at minimum is that the air gets cooled more but it doesnt save any fuel.
mtnrajdeep is offline   Reply With Quote
Old 29th November 2011, 13:36   #3
BHPian
 
falcon009's Avatar
 
Join Date: Dec 2009
Location: Bangalore
Posts: 88
Thanked: 4 Times
Default Re: Air condition in a diesel Car does not trip

Does ac cut-off happens in petrol? I have a ritz petrol but i never noticed cut-off happening.
falcon009 is offline   Reply With Quote
Old 29th November 2011, 14:26   #4
Senior - BHPian
 
mayankjha1806's Avatar
 
Join Date: Jan 2011
Location: BLR/Gurgaon
Posts: 2,133
Thanked: 820 Times
Default Re: Air condition in a diesel Car does not trip

Quote:
Originally Posted by falcon009 View Post
Does ac cut-off happens in petrol? I have a ritz petrol but i never noticed cut-off happening.
Yes it does cut off for various reasons. In my old Indica it used to cut off AC when the driver needs more power from engine (i.e. while accelerating hard it used to cut off AC). In my Baleno it cuts of AC after some time when the cabin get cooler (Climate control).
mayankjha1806 is offline   Reply With Quote
Old 29th November 2011, 14:26   #5
BHPian
 
TaurusAl's Avatar
 
Join Date: Mar 2011
Location: Mumbai - MH 01
Posts: 521
Thanked: 315 Times
Default Re: Air condition in a diesel Car does not trip

Quote:
Originally Posted by falcon009 View Post
Does ac cut-off happens in petrol? I have a ritz petrol but i never noticed cut-off happening.

Yes Falcon,

I have driven a Petrol Ritz and the A/c does cut-off if the blower is on 1 or 2 position and if the cabin cooling has reached decent levels.

Sad to note it does not happen in Diesel. But why not is the question ?
TaurusAl is offline   Reply With Quote
Old 29th November 2011, 14:56   #6
Senior - BHPian
 
anilisanil's Avatar
 
Join Date: Jun 2010
Location: Pune
Posts: 1,435
Thanked: 288 Times
Default Re: Air condition in a diesel Car does not trip

I did not realize this until I drove my diesel figo continuously for 400 odd kms with a/c on. It so happened that the a/c unit started forming ice or something and clogged the blowers because of which the a/c had to be stopped, I though it was some issue and visited the service center and they dismissed it as a normal occurrence and that the a/c would be back to normal once i switch off and switch it on after say 5 minutes.

But not too sure why the a/c does not cut off!
anilisanil is offline   Reply With Quote
Old 29th November 2011, 15:31   #7
BHPian
 
TaurusAl's Avatar
 
Join Date: Mar 2011
Location: Mumbai - MH 01
Posts: 521
Thanked: 315 Times
Default Re: Air condition in a diesel Car does not trip

Ok, so now we have reached a conclusion that the A/C does not get cut-off in Diesels, when i asked the same to the service guy of Maruti, he said something like 'The Pump will work less if your keep your blower low'.

I really did not understand what he said. Can anyone put a light on this ? If there is any point in keeping the blower low in a diesel car, and will it save anything at all ?
TaurusAl is offline   Reply With Quote
Old 29th November 2011, 15:46   #8
Team-BHP Support
 
Jaggu's Avatar
 
Join Date: May 2004
Location: Bangalore
Posts: 17,748
Thanked: 7,466 Times
Default Re: Air condition in a diesel Car does not trip

Yes DDiS does not have compressor cut off based on temperature. It just stays ON all the while. I feel this is to avoid the jerks when a compressor kicks in and out. When you switch ON the AC the ECM changes the fuelling in DDiS and compensate for the power loss, also at idle you will see compensation of about 500 rpm.

Long back i had checked with one of the service advisers and they also did not have anymore info than this.
Jaggu is online now   (2) Thanks Reply With Quote
Old 29th November 2011, 15:56   #9
BHPian
 
Figopian's Avatar
 
Join Date: Jul 2010
Location: Pune
Posts: 351
Thanked: 98 Times
Default Re: Air condition in a diesel Car does not trip

Quote:
Originally Posted by anilisanil View Post
I did not realize this until I drove my diesel figo continuously for 400 odd kms with a/c on. It so happened that the a/c unit started forming ice or something and clogged the blowers because of which the a/c had to be stopped, I though it was some issue and visited the service center and they dismissed it as a normal occurrence and that the a/c would be back to normal once i switch off and switch it on after say 5 minutes.

But not too sure why the a/c does not cut off!
Didn't we discuss the "thud" sound that sometimes we hear in Figo is the sound made by the A/C compressor start/stop in the Figo thread? I think this is happening because of the mounts being used in Figos? Now, if that is not A/C compressor being turned on/off what that sound is?
Figopian is offline   Reply With Quote
Old 29th November 2011, 16:00   #10
Senior - BHPian
 
anilisanil's Avatar
 
Join Date: Jun 2010
Location: Pune
Posts: 1,435
Thanked: 288 Times
Default Re: Air condition in a diesel Car does not trip

Quote:
Originally Posted by Figopian View Post
Didn't we discuss the "thud" sound that sometimes we hear in Figo is the sound made by the A/C compressor start/stop in the Figo thread? I think this is happening because of the mounts being used in Figos? Now, if that is not A/C compressor being turned on/off what that sound is?
I think that is the evaporator/radiator fan turning on. But yeah you could be right, but I am clueless on why there was "ice" formation if there was a thermostat, I've read other members facing the same issue. But then again, this is my "assumption" and I might very well be wrong.

Edit: I stand corrected. looks like Figo does have a thermostat to cut off the compressor. So this issue is specific to Maruti/DDiS!

Last edited by anilisanil : 29th November 2011 at 16:04.
anilisanil is offline   Reply With Quote
Old 29th November 2011, 16:00   #11
GTO
Team-BHP Support
 
GTO's Avatar
 
Join Date: Feb 2004
Location: Bombay
Posts: 47,729
Thanked: 89,228 Times
Default Re: Air condition in a diesel Car does not trip

Quote:
Originally Posted by Jaggu View Post
Yes DDiS does not have compressor cut off based on temperature. It just stays ON all the while.
Wouldn't that wear out the compressor significantly faster? Also, the air-conditioner might result in lower FE, relative to other diesel hatchbacks (not that anyone complains about the Swift's FE).
GTO is offline   (1) Thanks Reply With Quote
Old 29th November 2011, 16:06   #12
Distinguished - BHPian
 
libranof1987's Avatar
 
Join Date: Sep 2010
Location: All over!
Posts: 3,728
Thanked: 2,829 Times
Default Re: Air condition in a diesel Car does not trip

This is news!

Is this across all diesels? What's in a diesel car that prompts the compressor to not cut-off ?

And how come it's coming as a surprise to most of us - in the sense, never discussed earlier.

Quote:
Originally Posted by falcon009 View Post
Does ac cut-off happens in petrol? I have a ritz petrol but i never noticed cut-off happening.
A/c cut-off definitely happens in petrol; I've noticed it in all the 3 petrol cars I have.
libranof1987 is offline   Reply With Quote
Old 29th November 2011, 16:09   #13
Team-BHP Support
 
Jaggu's Avatar
 
Join Date: May 2004
Location: Bangalore
Posts: 17,748
Thanked: 7,466 Times
Default Re: Air condition in a diesel Car does not trip

Quote:
Originally Posted by GTO View Post
Wouldn't that wear out the compressor significantly faster? Also, the air-conditioner might result in lower FE, relative to other diesel hatchbacks (not that anyone complains about the Swift's FE).
Wear tear part is debatable.

A constantly running compressor will wear out sooner than occasionally run compressor, but the part which is most prone to failure aka the compressor clutch will last more if the ON and Off's are less.

FE again, one theory says due to more load it will go down. Another one says cut off will result in temp drop, which in turn results in more work from the compressor when it kicks in. Instead have a compressor which runs constant but in relative lower load (read as temp setting is low), draw back being AC cooling will take more time. So too many theories.

But fact is it (cut off) is not there, why? well the suzuki guys have hit some road block at design that they designed it this way.

Always wanted to know if the same engine in the Fiat also has same quirkiness. Also the vehicle with automatic climate control, how do they work along with DDiS?

Will ask the SA again all these questions next time around.
Jaggu is online now   (1) Thanks Reply With Quote
Old 29th November 2011, 16:16   #14
Distinguished - BHPian
 
libranof1987's Avatar
 
Join Date: Sep 2010
Location: All over!
Posts: 3,728
Thanked: 2,829 Times
Default Re: Air condition in a diesel Car does not trip

Quote:
Originally Posted by Jaggu View Post
FE again, one theory says due to more load it will go down. Another one says cut off will result in temp drop, which in turn results in more work from the compressor when it kicks in. Instead have a compressor which runs constant but in relative lower load (read as temp setting is low), draw back being AC cooling will take more time. So too many theories.
But the thing is - when you have the A/c compressor running all the time, it just keeps getting cooler in the cabin which could/would lead many to actually switch the A/c off - effectively having the same end-result, if not worse, that the auto cut-off compressor has.

Also, given the wear and tear part - A/c units with the ACC feature should wear out much earlier than those without, right?
libranof1987 is offline   (1) Thanks Reply With Quote
Old 29th November 2011, 16:25   #15
BHPian
 
Figopian's Avatar
 
Join Date: Jul 2010
Location: Pune
Posts: 351
Thanked: 98 Times
Default Re: Air condition in a diesel Car does not trip

Quote:
Originally Posted by anilisanil View Post
I think that is the evaporator/radiator fan turning on. But yeah you could be right, but I am clueless on why there was "ice" formation if there was a thermostat, I've read other members facing the same issue. But then again, this is my "assumption" and I might very well be wrong.

Edit: I stand corrected. looks like Figo does have a thermostat to cut off the compressor. So this issue is specific to Maruti/DDiS!
If you stand outside the vehicle with A/C switched on, you could hear one hissing sound, I am assuming that is A/C compressor sound and it does go away for a while intermittently, that is the reason for me to consider that the A/C compressor goes on/Off in my diesel Figo. Could it be the evaporator/radiator fan? I don't know, if that fan will make this kind of hissing noise.

Also, I don't get why this facility would be there for petrol engines and not for diesels? Interesting to know though!
Figopian 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
Air-con: Center vents throwing out warmer air than side vents? 90Horses Technical Stuff 82 7th July 2015 16:03
Terrible Chevrolet Beat Diesel experience: Problems with engine, suspension & air-con GTO Technical Stuff 19 8th June 2015 07:40
Air-con Blower not working silver_shadow Technical Stuff 17 27th March 2015 05:25
Air-con repair & installation - Amjad Car A/C (South Delhi) ankur_gupta10 Delhi NCR 1 10th July 2014 16:09
High pressure car washer using air compressor recshenoy Modifications & Accessories 2 1st October 2009 09:59


All times are GMT +5.5. The time now is 04:26.

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