[Silver Knight]

It will be mostly a radiator fan issue. It May appear to be a simple issue, however, get it sorted out immediately. Else complications due to engine overheating can create other issues.

[Ravi Parwan]

The Radiator fan should come on as soon as the AC is switched on. once the car is at running temperature, the fan should run continuously to cool the condenser. If the fan is switching off despite the AC being on, then the Fan circuit has a problem.

Your pipes being moderately cool and proper cooling at speed are mixed signals. One can't be happening with the other, if the refrigerant is low. I believe this is again linked to the radiator fan speed.

[greenhorn]

My Indica has an RPM sensitive AC cutoff - It works only within a certain range of RPM's - too low and too high and the AC will cutoff.

Sometimes when the lower cutoff is too low or the idle rpm is too low, this leads to no cooling. I would add that as a potential step - try running the car at idle at higher RPM and see if there is still cooling

[sureshkishore]

Had same issue in my old 2007 SX4, was easily diagnosed as a faulty condensor fan. Got it replaced at dealership. Part was quite pricey at 18k.

[virage]

Originally Posted by dhanushs

I think you are referring to the engine fan. How many fans does the fluidic Verna have? One for AC and one for Radiator? Or One is common?

Verna has only one fan, this fan does come on by itself as soon as the ac is turned on. I followed the advice from all the previous comments and did inspect the fan thoroughly.

So I took the car to an AC specialist, He hooked up the gauge on the low-pressure line and let the AC run. After about 10 minutes, the garage owner said the pressure looks fine and was doubtful that the AC was faulty at all. I insisted that the AC was indeed faulty and it would stop blowing cold air after a few minutes. He put a temperature probe into the AC vent and let it run for 20 minutes and I was watching the Temperate like a hawk.



Do you see the issue? . The AC worked like a charm.

The AC guy and I were trying to figure out how to get the problem to show up and thats when we realized that the place we were testing; it was pretty cool and was relatively shady due to a lot of trees and on top of that, we had the bonnet open to hanging the gauge. We finally honed in on the condenser not being able to dissipate heat effectively with the bonnet closed.

So we took the car to a car wash and we pressure washed the condenser.
The AC guy advised me to take the car home and use it for a few days. If the issue Pops up again he asked me to bring the car in when the sun is at its highest.
Paid 150 for the pressure washing, the AC mechanic refused to take any money since he didn't do anything ( People like this are a rare few !)

In the 24 hrs since cleaning the radiator, the Cooling performance has improved dramatically. I Turned on the AC and left the car under the sun in an area without airflow and the cabin did cool down in 10 minutes.


Thank you for your helpful comments, this turned out much simpler than I expected.

Now I have a question, is there a service interval for car AC, is there anything specific to be done during an oil change service?

Cheers

[sagarpadaki]

Good to hear that cleaning the AC condenser solved the problem. There is one thing that you can do as a DIY to help keep your AC in good condition, ie, Check the condition of the cabin air filter every 6 months and replace it if dirty. The AC filter is the best insurance to your car's cooling system. They are cheap and easy to replace. I think for Verna, it is behind the glovebox or in the passenger footwell.

Also, if you have access to water outlet, wet and spray the condenser with a soap solution, like a dish wash liquid and let it sit for a minute or two before rinsing of with running water from a pipe or pressure washer if available.

Do this along with the AC filter check and the AC will work flawlessly even in peak summer.

[Annibaddh]

Originally Posted by virage

I could not find a thread that has the same problem hence creating a new thread. Mods please feel free to move it to an appropriate thread.

I own a 2014 Fluidic verna Petrol 1.6; I am noticing an interesting behavior with the air conditioner.


The AC cooling does not improve with engine speed, I revved the engine at a standstill for a few minutes and it did nothing.

The Engine temperature is normal and the car does not overheat.

I've a whole thread on this exact same problem in my Vento. Here's what you need to do:

1. Get the radiator cleaned. Most likely this is the culprit.
2. Get the following parts checked: Radiator-fan - you can do this yourself. After any particular longish drive check if the fan is working when you park the car on the side. Get the water pump and coolant levels also checked. Ask the FNG to check if the coolant is circulating well, levels can look ok but coolant circulation may not be efficient.
3. If the above steps don't solve the problem (my hunch is they would) the final step is to get the head faced.

Bests. For reference, I had to go through multiple stupid steps at VAG ASS (pun unintended) and the asses could not assess (this one and the alliteration IS intended) the problem. Changed water pump, radiator fan, timing kit, temperature control sensor and set me back a cool 60K before an FnG mechanic (World of Service, Noida) with experience at VAG told me they only claim to clean the radiator but never really do. One visit and voila!

[Sarinkrc]

I had a similar issue with Honda City. When the ac is on and when car goes slowly or in traffic or is in standstill idle position the ac doesn't cool and the engine heating starts blinking. The car was around 2 years old that time and run 17000km. I took to the dealer and they said compressor and condenser needs to be replaced for an estimated price of Rs 1 lakh. Well after a few months took the local mechanic and they cleaned up the clogged coils and topped up ac gas and i never faced the issue for around Rs 3000. The reason was that the car was lying unused for around 10 months before that so waste had accumulated in the system . Best thing to do is to check up with a trusted mechanic i would say.

[PSM_360]

I am very thankful that this thread came up and the symptoms are very similar to what I am facing with my Dad's 2014 Honda City VX iVTEC CVT (4G) for years now.

Symptoms: OP + my add-ons:

Originally Posted by virage

-The AC does not blow cold air at standstill during the daytime.
-When the car gets up to speed, the AC starts blowing cold air and stops immediately when the car stops moving.
-When the car starts for the first time in the morning the first few minutes are cold.
-The cooling is very good during the night and long drives.

-Being a CVT car, if I drive on D within city traffic (1000~1800 RPM) cooling is poor. If I drive on S within city traffic (>2100 RPM), cooling is better (similar car speed). Means cooling is proportional to engine rpm.
-At standstill (on N), if I rev the car to >2000rpm and hold, it cools better than at idle. Again, cooling seems to be proportional to engine rpm.

Two years back I got it checked at Honda ASS during a service. They serviced the AC (not by opening the dashboard). The service advisor revved and hold the engine at >2000 RPM and showed that AC is blowing cold air. I said okay and realized later that why he revved the engine to show cooling. Most probably he was aware of this behavior.

Last year, during service at Honda ASS, they pointed it to the compressor and asked to get it replaced. Later, got checked outside by a car AC service specialist. He plugged in the pressure gauges and stated that the blue pressure gauge is fluctuating, again pointed towards a faulty compressor. Later came to know from several people that he works for an adjoining shop that sells car AC systems, so always convinces on replacing expensive parts.

Still, I have not got it fixed as no one could provide me a convincing solution. After reading various suggestions in this forum, again had a look at the behavior of AC, especially fan-related.
-The car has two fans behind the condensor+radiator setup.
-At idle, when AC is off, both fans turn on at a fast speed when the engine is hot and turn off automatically.
-At idle, when AC is on, both fans always turn on but at a slow speed. Speed remains slow. Compared this scenario with my cousin's 2017 Honda City iVTEC V MT and found something different. On his car in this condition, fans kept on switching between slow and fast speeds.
-At a standstill, I revved the car around 3000±500 rpm for some time. Cooling became good compared to idle rpm. Repeated the same after 2 minutes, it didn't cool at all, even at high RPMs. Wierd inconsistent behavior.

I am yet to check for fuse/relay-related stuff for fans which I will do this evening.

Hoping for your useful suggestions. Thanks.

[pixantz]

Originally Posted by PSM_360

the blue pressure gauge is fluctuating, again pointed towards a faulty compressor.

-At idle, when AC is off, both fans turn on at a fast speed when the engine is hot and turn off automatically.
-At idle, when AC is on, both fans always turn on but at a slow speed. Speed remains slow.
I am yet to check for fuse/relay-related stuff for fans which I will do this evening.

Hoping for your useful suggestions. Thanks.

Your observation of the Low-side pressure(blue) FLUCTUATING is a tell-tale sign of compressure Malfunction provided it FLUCTUATES AT A STEADY ENGINE RPM which should be noted, importantly. If it moves a bit in tandem with RPM whichever ways, it's ok. It shouldn't move around more than about 10-15 psi max, whichever ways.

Further, your observation about the fans is confusing. AFAIK, cars with two fans, specially Hondas don't have variable fan speeds except in cases of older Hyundai like the older Accents etc. Also,
TATA cars, mostly older models work that way. Maybe you was listening to the fans with a closed bonnet and judging by sound?

As far as I know, Hondas have the chunkier Radiator fan doing the job, either alone or with the other one, for engine cooling in event of Ac being Off. When Ac is On, both fans work continuously and cut Off in tandem with Compressor. All this at Full speed or fixed speed.

Cars with single fan, which is the style in all newer cars, have a thermostat controlling the fan speed. This thermostat gets input for speed commands from the ECU/BCM as to what speed at what time. The ECU in turn works its algorithms with inputs from various sensors like the pressure sensor in the Ac lines, thermostat valve temperature sensor/s, ambient temperature sensors, etc. It's a different ballgame. Hope this helps.

Your issue doesn't seem fan related If that pressure fluctuation holds any truth. If thats not the case it could be anything from insufficient/overcharged refrigerant, clogged Condensor, dirty cabin filter/evaporator, etc.

[sagarpadaki]

Originally Posted by PSM_360

I am very thankful that this thread came up and the symptoms are very similar to what I am facing with my Dad's 2014 Honda City VX iVTEC CVT (4G) for years now.

.

Can you check if other Honda City of your model has the issue?

Did you try cleaning the condenser with soap and pressure water? If yes, did it make any difference to cooling? If no, you can give it a try.

Was the car AC gas refilled anytime before? High or low gas quantity than the recommended also can lead to insufficient cooling. Not to mention, it can also damage the compressor. Every car model has a specific quantity of refrigerant that has to be present in the system. Typically, this is between 400-500 grams for the most mass market cars. The exact quantity info can be got from the service center or from any of those AC shops that have the automatic AC gas charging machines.

[pawank]

There can only be two problems with your car.
1. Bad AC compressor
2. Faulty temperature sensor of the evaporator

As the AC is cooling fine at night, the most probable cause would be the faulty temperature sensor of the evaporator.

[pixantz]

Originally Posted by pawank

There can only be two problems with your car.
1. Bad AC compressor
2. Faulty temperature sensor of the evaporator

I don't think it can be the thermistor(evaporator sensor) because that guy is pretty distinctive and causes mainly two problems:
1)Compressor doesn't turn on if it's stuck open. So complete cooling shut-off.
2)Compressor doesnt cut off causing icing in the evaporator leading to subsequent air flow blockage and less cooling if it's stuck closed circuit.


That said, I think the best way to pinpoint Ac issues is with a proper hands-on diagnosis because the problems here are pretty much common and that is insufficient, erratic or no cooling. But the causes could run into thousands of different component malfunctions depending on vehicle or a combination or correlation of them.

Further, according to different manufacturers and the way they build their cars differently, the problems and symptoms vary accordingly. Sometimes the Ac itself doesn't have a problem but it can malfunction because of an issue that is OUTSIDE of the Ac system altogether.

Like the case of Audi/VW/Skoda where their Ac system are very robustly built but are very sensitive to the engine cooling systems and whenever the Ac malfunctions,
more than 90% of the time the culprit is the engine cooling system. And here the components are many like Primary Water Pump, Auxillary Water Pump, Coolant Controller Valve/s, Sensors, so on and so forth. Any irregularity in the working of these or a combination causes the Ac to Malfunction first thing. That's the way its built. Ask the VW owners and they will be nodding in approval. So the proper diagnosis is of prime importance.

Its all so interesting. And varied.

[AntPaul]

AC vent temperature of 12.4 Celsius is quite high AFAIK. Last week when I went to get my 15 year car for its regular ac gas top up, the vent temperature dipped to 3.5 Celsius in 5 minutes.

The trick AC service center does to reduce vent temperature is to pour out water on the condenser to cool it faster. You could also try it, Let you AC run in stationary car till you feel unsatisfied with the coldness of air, let the condenser get warm, now pour water on to the condenser. If AC starts blowing colder air again that means the condenser is not able to dissipate heat. Could be a weak radiator fan /ac fan, or clogged fins.

If the same fan does duty for both AC and radiator, then there must be 2 stages in which the fan operates. I hope you have verified that the fan does go to higher speed when engine begins to get hot after prolonged idling.

[samitjain]

Guys, I have a 4th gen honda city and the ac cooling is not up to mark. I have taken my car to ASS 2 times, but they say all the parameters are within range and cooling is ok.

I know I am comparing cooling of city with other cars I own it’s worst of the lot. It just manageable with ac. It never chills.

As per ASS, it’s the car ac system which is just this much capable. The grill temp touches minimum of 6.5 degrees and it takes awful time to reach it.

As per ASS they have changed compressor from 3rg gen city which had excellent ac to a cost effective in 4th gen., hence inferior cooling. Also everything controlled by ECU they can’t do much.

Suggestion to improve cooling. Relatively new car , under warranty and about 20000 km done . Mails also written to honda buy ASS says that since everything is within parameters nothing much can be done. Even the parameters are so wide that almost every ac will fit within those .

Sat in other cars of same generation and cooling was similar, not great.

Suggestions required.

My suggestion - Don’t go for Honda City