[Col Mehta]

Dear members,

Our Grand i10 petrol 2015 model has this strange hissing noise issue from its early days. Thing is, everytime you increase car's RPM (regardless of car moving or being stationary) with ac on, an intermittent hissing noise is heard for a couple of seconds, which disappears and comes back again in a few seconds. Also, while driving, a minor jerk and loss of power (noting major) are felt when the hissing sound starts.

Hyundai service centers are clueless about this issue. My son, who primarily drives this car, has given up on it now and has started living with this but I'm not convinced. Last year we happened to check a brand new Grand i10 (pre-facelift) and that car also had the same irritating noise and feedback. HASS says this is how it's being designed for better performance/fuel efficiency and what not absurd stories .

AC gas level was checked which was quite low - refilled but no luck. Experts, please help. Thanks!

[naveen.raju]

Originally Posted by Col Mehta

Experts, please help. Thanks!

It's there in my wife's car. Although not loud, it's quite audible and noticeable when compared to my Creta (my wife didn't complain). It's been there right when we bought the car.

So I guess it works this way.

[pkulkarni.2106]

Originally Posted by Col Mehta

Dear members,

Our Grand i10 petrol 2015 model has this strange hissing noise issue from its early days. Thing is, everytime you increase car's RPM (regardless of car moving or being stationary) with ac on, an intermittent hissing noise is heard for a couple of seconds, which disappears and comes back again in a few seconds. Also, while driving, a minor jerk and loss of power (noting major) are felt when the hissing sound starts.

Hyundai service centers are clueless about this issue. My son, who primarily drives this car, has given up on it now and has started living with this but I'm not convinced. Last year we happened to check a brand new Grand i10 (pre-facelift) and that car also had the same irritating noise and feedback. HASS says this is how it's being designed for better performance/fuel efficiency and what not absurd stories .

AC gas level was checked which was quite low - refilled but no luck. Experts, please help. Thanks!

Well, this happens with my Santro as well. I have this hissing sound whenever the compressor kicks in. And for reasons unknown, the AC cuts off every now and then (it's prominent in 1st gear when I release the clutch). I have serviced the AC couple of times in last 4 years, but the hissing wouldn't go away. Also, the FNGs are clueless why the AC cuts off the way it does.

Next month, I'm planning to take the car to Hyundai A.S.S. for servicing. I'm planning to get it scanned (I have other issues e.g. sluggish performance), to see if they find out the reason behind this.

[Col Mehta]

Originally Posted by naveen.raju

It's there in my wife's car. Although not loud, it's quite audible and noticeable when compared to my Creta (my wife didn't complain). It's been there right when we bought the car.

So I guess it works this way.

Do you have similar issue in your Creta too? Never had it in our Creta. Thanks.

Originally Posted by pkulkarni.2106

Next month, I'm planning to take the car to Hyundai A.S.S. for servicing. I'm planning to get it scanned (I have other issues e.g. sluggish performance), to see if they find out the reason behind this.

Would be helpful if you could update once done. Thanks .

[sgiitk]

Originally Posted by pkulkarni.2106

Well, this happens with my Santro as well. I have this hissing sound whenever the compressor kicks in.

Next month, I'm planning to take the car to Hyundai A.S.S. for servicing.

afaik the ASS is as good as a Ass. Better go to a good reputed car AC guy in your city. He can do a far better job. On my Brio the compressor had packed up, after a few hours the ASS came down to the same conclusion. The Car AC guy just did a compression check and came down to it in about 5 minutes. I got a new compressor and condenser and things are Ok. I had a small problem with the blower - speed 1 is very slow. Well I am living with it, since the blower assembly is not available.

[pkulkarni.2106]

Originally Posted by sgiitk

afaik the ASS is as good as a Ass. Better go to a good reputed car AC guy in your city. He can do a far better job. On my Brio the compressor had packed up, after a few hours the ASS came down to the same conclusion. The Car AC guy just did a compression check and came down to it in about 5 minutes. I got a new compressor and condenser and things are Ok. I had a small problem with the blower - speed 1 is very slow. Well I am living with it, since the blower assembly is not available.

Sir, it's kind of tricky in my case.
As per the FNG, AC should cut off in only two cases:
1. It has reached maximum cooling
2. ECU detects wide open throttle

Now, apart from AC being cut off, my car suffers from intermittent sluggishness and random drop in FE. He thinks that the TPS might have gone bad in my case. So the TPS is sending wrong signals, hence ECU cuts off the AC. This also aligns with why there's random drop in FE.

As Santro doesn't work with OBD-II, he suggests me to visit A.S.S. once to get it scanned.

Coming back to Col Mehta's post:

Originally Posted by Col Mehta

Thing is, everytime you increase car's RPM (regardless of car moving or being stationary) with ac on, an intermittent hissing noise is heard for a couple of seconds, which disappears and comes back again in a few seconds. Also, while driving, a minor jerk and loss of power (noting major) are felt when the hissing sound starts.

I'd like to know if you floor the A-pedal when you say you increase the car's RPM. Because that would explain why it cuts off the AC (hissing stops in this case for you).

Thanks!

[Col Mehta]

Originally Posted by pkulkarni.2106

I'd like to know if you floor the A-pedal when you say you increase the car's RPM. Because that would explain why it cuts off the AC (hissing stops in this case for you).

Thanks!

The noise is heard irrespective of how hard or light the acceleration input is. Basically, directly proportional to increase in RPM. Thanks.

[naveen.raju]

Originally Posted by Col Mehta

Do you have similar issue in your Creta too? Never had it in our Creta. Thanks.

Sorry, I meant it's not there in the Creta.

[sgiitk]

Originally Posted by pkulkarni.2106

I'd like to know if you floor the A-pedal when you say you increase the car's RPM. Because that would explain why it cuts off the AC (hissing stops in this case for you).

Thanks!

Most cars (esp Auto) have a kickdown mode where if you floor the throttle the AC compressor is cut off. Natural since all resources should be available for acceleration. This must be manifestation of this.

[pkulkarni.2106]

Originally Posted by sgiitk

Most cars (esp Auto) have a kickdown mode where if you floor the throttle the AC compressor is cut off. Natural since all resources should be available for acceleration. This must be manifestation of this.

Exactly.

Originally Posted by Col Mehta

The noise is heard irrespective of how hard or light the acceleration input is. Basically, directly proportional to increase in RPM. Thanks.

By reading your original post, I thought there were two issues:
1. Hissing sound when AC is ON
2. Hissing sound disappears and comes back again

For first issue, I never found solution. Many forums say that the hissing sound is a result of AC gas being on lower side. But I never managed to get rid of it even after topping the gas and/or full AC service.

Some say that it's because of the "expansion valve". Hissing sound is generated as the gas leaves the valve, and "adjusting" or replacing the valve should solve the issue. I started to live with this noise, and never bothered to "adjust" or replace the valve.

Second issue is your AC is getting cut off intermittently.
For the this issue, I was interested to know if you floor the throttle.
Disappearance of the hissing sound (i.e. compressor is cut off) when you floor the throttle (or accelerating hard) would make sense.

If that's not the case, then could it be a problem with all Hyundai's, that even under light acceleration it cuts off the AC?

[Col Mehta]

Originally Posted by pkulkarni.2106

If that's not the case, then could it be a problem with all Hyundai's, that even under light acceleration it cuts off the AC?

Thanks for your inputs. I'm not sure if the hissing noise cuts the ac off. Saying this because it doesn't affect the cooling in any way. The cooling is quite good and we never felt ac to be insufficient or malfunctioning, regardless of how many times the hissing noise appears. And as you mentioned, we did try topping up the gas which didn't help either.

I think this is an inherent issue with most of the Hyundais. Every single grand i10 and Xcent we tried had this issue which, in my opinion, is absolutely ridiculous. Seems like Hyundai is using inferior quality parts in some of their models. Thankfully, out Creta doesn't have this irritating noise.

[pixantz]

Originally Posted by Col Mehta

I think this is an inherent issue with most of the Hyundais. Every single grand i10 and Xcent we tried had this issue which, in my opinion, is absolutely ridiculous. Seems like Hyundai is using inferior quality parts in some of their models. Thankfully, out Creta doesn't have this irritating noise.

The smaller Hyundai cars have the ecm cut off the compressor instantly for a moment if it senses the engine getting bogged down due to either sudden acceleration or a situation where the engine has the possibility of stalling. If you gradually accelerate, this will not occur, especially if the car is in ship shape.

This setting maybe helps initial acceleration and is a kind of safety mechanism but most people wouldn't realize it happens unless you really keep tabs on it.

Hissing is mainly due to low gas but the exact type of hissing will need to be heard upfront to really determine. It could be something else too.

Your Creta has the more modern type of Ac where the compressor doesn't have a clutch like the ones on an old i20 or i10 or Santro etc. So you won't hear it cut off or on, because it doesn't operate like that at all. It has an internal solenoid valve which regulates the gas continuously so there is no off/on business. It's what the home appliance people call "inverter" Ac. Hope this helps.

[Col Mehta]

Originally Posted by pixantz

The smaller Hyundai cars have the ecm cut off the compressor instantly for a moment if it senses the engine getting bogged down due to either sudden acceleration or a situation where the engine has the possibility of stalling. If you gradually accelerate, this will not occur, especially if the car is in ship shape.

Unfortunately, the hissing noise occurs even during gradual acceleration also. Thing is, as long as the engine RPM is anything above 1K mark with ac on, the hissing noise is produced for a brief moment which at times results in minor jerk and loss of power during driving.

Also happens when the car is not in motion - start the car, switch the ac on, while the car is standing, press the A pedal gradually, let the RPM cross at least 1K and there you go, the hissing noise is heard - But one important characteristics we have noted is the moment hissing noise is stopped, the RPM sort of jumps without any additional A pedal input (nothing very dramatic though, say from 1K to 2K) - as if something was holding the engine back during hissing noise. The A pedal feels - free. It again feels restricted during hissing noise and comes back alive the moment hissing noise is stopped. Not sure if I have made it easier (or more difficult) to understand.. Let me know .

Originally Posted by pixantz

Your Creta has the more modern type of Ac where the compressor doesn't have a clutch like the ones on an old i20 or i10 or Santro etc. So you won't hear it cut off or on, because it doesn't operate like that at all. It has an internal solenoid valve which regulates the gas continuously so there is no off/on business. It's what the home appliance people call "inverter" Ac. Hope this helps.

Thanks for this useful piece of information .

[Catalyst_delhi]

I have this in my Figo Diesel since day 1, AG gas is at 510 grams which is at spec, grill temp is as per spec ( 2-3 Celsius at Delhi ambient) measured yesterday. It is to do with the expansion valve. AC cuts off to prevent freezing of the evaporator or when it reaches 0 Celsius. Had this sound for 4 years now so not touching anything till it breaks. I got used to this sound as well now. Also to Add A/C cuts off when engine is overheating as well for all cars , in addition to full throttle and AC evaporator temperature reaching 0 Celsius. I did a full evacuation, vacuum and refill as well just to be safe 2 years ago.

[k88k]

I have bought a Tigor XZA and the car has hardly done 100 kms. I am seeing small pieces of foam (grey) below the glove box compartment. Since I noticed this after a good running of AC for 25-30 kms, I guess it has something to do with it. Is there any problem with the AC or is it something else?