[newcoolgadgets]

My 2006 Zen VXi has done 22,000 kms and with this being its 3rd summer, the cooling of the AC has gone down. The flow of air from the vents is also reduced by almost 30%.

I went to Cool World at Ghat Road, Nagpur, and he looked under the dash, pointed a torch, (there is a plastic box which houses the cooling coils, I guess) and said that the cooling coils are choked with dust. He said he will need to clean and wash the coils. In addition he also said that the system needs to be flushed with Nitrogen and the gas has to be refilled. The compressor needs to be topped up with oil too. The estimate for this entire job has been given at Rs. 1800/-

My questions are:

1. Is it possible to open the cooling box under the dash and clean the dust at home?

2. I suspect the main reason for the drop in cooling and the air flow from the vents is the dust accumulation in the cooling coil box. Is it necessary to go in for a complete refrigerant gas refill?

3. Is it possible to know the level of the refrigerant in the system by looking at the small glass window in the AC system under the bonnet. If yes, how to read it?

4. Is Rs. 1800 fair for the above job?

Please let me know your views. I need the AC to work efficiently soon, as the temperature here is already 45 degrees!

[Jaggu]

Reply innline in bold.

Originally Posted by newcoolgadgets

1. Is it possible to open the cooling box under the dash and clean the dust at home?

Not recommended, its tedious and one wrong move can leave you with a nasty puncture at the aluminum grill

2. I suspect the main reason for the drop in cooling and the air flow from the vents is the dust accumulation in the cooling coil box. Is it necessary to go in for a complete refrigerant gas refill?

Yes it can be the clogged grill, but if you are dismantling the unit, you will have to do refill and along comes the comp oil also

3. Is it possible to know the level of the refrigerant in the system by looking at the small glass window in the AC system under the bonnet. If yes, how to read it?

If the gas is boiling at raised idle, gas levels are low

4. Is Rs. 1800 fair for the above job?

For complete job including labor and consumables, its ok charge.

Please let me know your views. I need the AC to work efficiently soon, as the temperature here is already 45 degrees!

[LLL]

Did you try checking with a MASS as well for a second opinion?

I had my santro AC svced for 1200 bucks from Hyundai dealer with pretty much the same issues as yours. I am sure a MASS would charge you somthing similar and give you peace of mind as well.

[newcoolgadgets]

Thanks for the response Jaggu. I saw a frantic white fog like activity through the glass when the idling was raised. Is this the 'boiling' you are talking about? If the gas is full, will the glass show a clear fluid?

[breezydrive]

For the same problem in my zen, MOTORCRAFT at NOIDA quoted Rs.2000

[anupmathur]

Originally Posted by newcoolgadgets

If the gas is full, will the glass show a clear fluid?

Yes, it will. With an optimal charge in the system, the glass will look completely transparent and you really will see no 'activity'.

[married2speed]

It's advisable to get the a/c cleaned after 16K of running but 1800 bucks appears to be on the higher side. I checked re: these charges for my city and i was quoted at 1600 Rs. at the honda service station. You'll be better of getting the car serviced at MASS or the dealer u purchased it from.

[newcoolgadgets]

OK! Well that confirms that I do need a refrigerant refill. So I guess the whole coil cleaning, nitrogen flushing, gas refill and compressor oil change routine is in order here. Will get it done tomorrow. I will go with Cool World as they did a terrific job of bringing my '87 Premier Padmini's retro-fitted AC back to life. Will post the results here when I am done.

Thank you Jaggu, anupmathur and others for your help!

[Jaggu]

Originally Posted by anupmathur

Yes, it will. With an optimal charge in the system, the glass will look completely transparent and you really will see no 'activity'.

yup maybe a teeny weenie bit when raised, thats all but no frothing business.

[newcoolgadgets]

Ok, so I went to Cool World first thing in the morning today. In fact I was there even before they had opened their shutters and had to wait for 10 minutes for the workshop to open. Their technicians got to work right away.

The technician first hooked up a machine to the AC system and flushed the system with Nitrogen. Then he disconnected the condenser unit from near the firewall. The dashboard on the passenger side had to be unscrewed partially to give access to the condenser box under it. Within a few minutes the condenser coil box was out. On opening it, we found it clogged with dust and leaves! He gave the coils a good wash under a spray of water. A little work with a toothbrush loosened the grime on the top. The cleaning product he used next just blew me away!

After washing the coils under water, the AC technician brought out a bottle of a milky white cleaning solution called 'See Shine'. He diluted it with water and then sprayed the solution into the condenser grill. Within a few minutes huge amount of foam like substance started oozing out of the condenser grill, bringing out with it all the clogged dust and grime. The foam kept on oozing for almost 3 minutes and the whole condenser grill was cleaned of dust. He then gave the grill another wash under water spray and cleaned the plastic box that houses the grill.

That done, the only thing remaining was to fit the condenser back and connect it to the system. Once connected, oil was filled in the compressor and refrigerant was filled. Within minutes I was experiencing the chills I used to when the car was new! The grill temperature was monitored and it was found that the AC compressor cut off at 6 degrees. The technician said that this is the cut-off temperature set by Maruti for the Zen. Is this true?

He said they can set it lower, but it is not advised as setting it lower may cause ice formation on the condenser grill and cause damage to the AC. Well 6 degrees is just fine by me, thank you very much!

The final cost of the entire AC servicing, cleaning, refrigerant refill, compressor oil, labour charges etc was Rs. 1800/-. As I drove away from the workshop it was already 41 degrees outside, but I was feeling the chills in my Zen! Even the air flow from the vents is back to normal and reaches the rear seats. And above all the air smells fresh. Thank you everyone for your words of advice.

[anupmathur]

Great that you have such a good workshop at Nagpur.
Now remember to NEVER open the selector to the fresh air position; always use the recirculation mode.

[newcoolgadgets]

Oh yes, I never use the re-circulation mode except on very rare occasions when I have been driving for more than an hour (which almost never happens here in Nagpur, as any place to any place in the city is 30 minutes away!)

I was surprised to see how the leaves (though there were only 2 or 3) got there along with the dust!

[Jaggu]

Glad that it is solved, and good write up will be useful for others to refer to. Grill temp usually vary from 4-6 deg, at 41 deg grill temp is pretty good and yes they are right if set low, it can cause freezing/icing which is a pain.

Enjoy the cool summer.

[Shankyz]

Any idea how to check the grill temp, a digital thermometer should do the job but where to get it and how much does it cost?

I had my M800 AC serviced last week at a MASS but they didn't do any Nitrogen Flush or cleaning the Condenser with the SEE SHINE or anything else, they just washed it with water and told that all chemical stuff used to clean the condeser by outside agencies ends up weakening the aluminium foils and will damage the condenser. Also, they didn't check the grill temp. I think I will ask them to check it for me, should I expect 6 deg too ? The AC is Subros (Stock) M800.

[newcoolgadgets]

The digital thermometer is a small device, as big as a clinical thermometer but with a digital display at one end and the temperature probe sensor at the other end. To check the grill temperature you need to insert the probe into the AC vent. Now set your cooling to maximum, blower to medium and start the engine and the AC. Keep the engine on a raised idle. As the temperature starts dropping, keep your ears trained to hear when the compressor cuts off. This will take 5 to 10 minutes depending on your AC capacity, size of the car and the outside temperature. The temperature at which the compressor cuts-off is your cut-off temperature. I guess for all cars it is set anywhere between 4 to 6 degrees.

If the temperature does not drop to 6 degrees or close to it, even after prolonged running, or if your compressor cuts off early, you will need to check your AC.

I did ask the AC technician about the chemical used to clean the condenser, but he assured me that if diluted properly, it does not harm the coils or weaken them.