[Akhil@Bengaluru]

I have a peculiar problem with my Manza QJT (One year old), If the AC is ON continuously for around One to Two hours (i.e if the car is cooled for around One to Two hours ) i get a continuous clicking sound from the AC vent which is just below the front glass. This happens only if the car is moving, if the car is stand still the noise will not be present.
Once accidently i learnt how to stop the sound temporarily, i just have to switch on the heater with Full Fan speed and put the Full fan to the AC vent which is just below the front glass for five minutes.
This will stop the problem for next two hours.
I could not show this issue to the TATA guys as this sound is coming mainly on High way trips, and when the car is taken to service center car AC behaves perfectly.. (Have tried this twice already)

Have tried to see if something is fallen into the AC vent but in vein.(if something which is inside is making noise it should make the noise continuously and not only when the car is running)

It is really irritating to hear the clicking sound on long drives, Anyone please help me to get the issue resolved.

[n.devdath]

Sounds like a relay or a thermostat to me which acts up after reaching a certain temperature. Did you have that checked?
OT: Is it not a rodent which cannot bear the cold after 2 hours and starts to scream?

[nandans2005]

If the AC is ON continuously for around One to Two hours (i.e if the car is cooled for around One to Two hours ) i get a continuous clicking sound

The thermostat does give the clicking sound, which is nothing but the thermostat switching ON and switching OFF. But i doubt this continuous clicking noise. Perhaps, the thermostat goes cranky ?

This happens only if the car is moving, if the car is stand still the noise will not be present.

Thermostat works once the AC is turned ON, irrespective of whether the car is moving or stationery.

It is really irritating to hear the clicking sound on long drives, Anyone please help me to get the issue resolved.

Probably you will have to spend sometime at the service center to get into detail properly.

[pvgeorge]

It coming should be the thermostat coming on and off. My Indica also gives these clicks with AC on. Some sort of a longish clicks.

I think in Tata cars these are placed inside the cabin and hence the noise

Regards,
George V

[prince_pervez]

I don't think there is anything to worry, if it is the thermostat auto-cutting after attaining the threshold temperature. But I must admit, the noise gets to me sometimes, in both my cars.

[Akhil@Bengaluru]

Dear All thanks for the reply,

Following few are some more observations

The noise should be coming continuously if the Noise is due to thermostat, but in my case the noise is coming only if the car is moving.

If i tightly press the AC Vent below the Front glass or the Dash board as a whole the noise will reduce to a great extent which makes me think is the noise due to some two parts touching each other while the car is moving (after AC is ON for around One to Two hours) ?

[alpha1]

Probably some expansion-contraction (due to heating cooling) of not so accurately machined or misaligned parts?

[Akhil@Bengaluru]

Originally Posted by alpha1

Probably some expansion-contraction (due to heating cooling) of not so accurately machined or misaligned parts?

Even i suspect the same issue, But how do i confirm or rectify that?

[SirAlec]

its normal. Its the thermostat that is shutting the compressor after sensing the predefined low temperature. Most cases its about 15 degree.

[Akhil@Bengaluru]

Originally Posted by SirAlec

its normal. Its the thermostat that is shutting the compressor after sensing the predefined low temperature. Most cases its about 15 degree.

If it is thermostat making that sound Will it be with so high frequency? (around 60 to 80 clicks per mins ?) and why it should stop making the noise if i press the AC Vent below the Front glass or the Dash board? and why it makes the noise only when the car is moving and not when stopped?
Some one help me to get the issue resolved.

[SirAlec]

and why it should stop making the noise if i press the AC Vent below the Front glass or the Dash board?

Please elaborate.

60 -80 clicks per mins, thats definitely not normal. I think you should get your AC checked with a reputed AC guy. Or you will end up burning your magnetic clutch of the compressor.

[Akhil@Bengaluru]

Originally Posted by SirAlec

Please elaborate.

60 -80 clicks per mins, thats definitely not normal. I think you should get your AC checked with a reputed AC guy. Or you will end up burning your magnetic clutch of the compressor.

Its more like some hard plastic part or metal part getting rubbed against plastic, but happens only when AC is ON for more than one hour. i suspect parts rubbing as it comes only during running the car and when i press the AC Vent below the front glass the sound reduces completely, But for sure it is related to car AC.

[Cityrover90]

Hi, can any one please tell me the best way to change the coolant thermostat? The housing unit appears to be in a very awkward position under the ignition coil pack, and the bolts are hard to get to. I have thought about taking out the air filter housing unit but is that necessary? Can I take of the ignition coil pack and get to them that way?
Thank you for any help! =)

[msaudf]

hello cityrover

a picture speaks a thousand words, giving some details of the car brand and model would also help in sugessting how you could solve the issue.
cheers.

MODS: you could move this to an appropriate thread so that the member gets more responses.

[Cityrover90]

Originally Posted by msaudf

hello cityrover

a picture speaks a thousand words, giving some details of the car brand and model would also help in sugessting how you could solve the issue.
cheers.

MODS: you could move this to an appropriate thread so that the member gets more responses.

Hi, it's ok. I've been able to change it now and it seems to be in good working order. Thank you for your interest in the matter though :-)