A/C blows warm air ...

There is a good chance that it just needs freon. As far as the sealer, if there is a leak, it will help. This guide will help

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak


Please run down this guide and report back.

i had just recarged my ac at a shop, and now its two weeks later and it went out i looked for leaks could not find any, anything i should look for.

first need gagues to determine if fault is freon loss. If so then go over system with a halogen leak detector to find leak

Hello,

I own a 2001 Nissan Sentra and i have just recently had problems with my AC. It works when i drive (Not as cold as it was before it started acting up but cold enough)but when i idol or stop at a stop sign it blows only hot air. What is wrong with it and how can i fix it? Will it cost me an arm and a leg to get it fixed? I need help alot because where i live it is dry season and hotter than a desert in the summer.

Thank you,
Denise P. Guam

Hi Denise,

Check cooling fans to see if both are working when AC is turned ON.
Get the low and high pressure readings and let me know the results.

This has me puzzled. My heater works great as long as I am driving a distance. However, if I am in town to run errands it starts blowing cold. If I want to warm my car before leaving for work it only blows cold. The rmps have to be high in order for it to blow warm. It worked great last winter and it does this winter as long as I"m not in town. Example.. I left work to come home which is appx 12 mles. I have to run to the store and within 3 to 4 minutesof driving in town it only blows cold. As soon as I leave town where I"m driving 55mph it is blowing warm as it should. Any suggestions???
My car is a 2000 Nissian Sentra 1.8 engine.

Check the coolant level if okay test the thermostat and check for blockage on the heater core everything okay so far-could be door problems, vacuum/actuators and HVAC control module.

Okay thanks but.... I just replaced my thermostat and the heater core has been flushed. The door whatever you want to call it is controlled by a cable and it was also checked. Any other suggestions????

All of a sudden my a/c starting blowing nothing but hot air and there seems to be no obvious issues. the compressor was changed at the end of last summer, so it is brand new. please help with any suggestions as to what may cause this. thanks.

Could be low on freon, if they missed a leak.I would start by having the pressure checked to see if there is enough in the system for the compressor to turn on.

I have a 2000 Sentra Se 2.0, about 145K. AC worked, but took a while to get cold, and didn't get as cold as it used to. I figured it just needed a recharge.
I took it to a generic tire and auto place, and was told the low pressure line was leaking. Since the place dealt mainly with tires and suspension, I decided to take it to a place I trust.
This place didn't find the leak in the low pressure line, but when they went to recharge the AC system, they found a broken seal in the compressor and all the fluid leaked out. They told me that the compressor needed to be replaced. I normally trust this place, but my repair estimate just jumped from 250 to almost 1000. Can you tell from this info which place gave the right diagnosis?
Also, will a remanufactured compressor work as well as a new? I plan to keep the car as long as possible, so is it worth an extra $300 to buy new?
Thanks

If the car cools at all there must be some refrigerant in the system. I don't know what you have been charged so far but if it has held a charge to cool some it might leak but where is the question. You have another option to purchase a kit and try it yourself. They also have a dye that can help you determine where a leak is actually located on the system. I think any parts store has this and Walmart might even. They do carry the recharge kits. I would find the leak location and note how fast the refrigerant leaks out.

Reman or new? That is your choice. What warranty comes with each of them? That is what I would want to know.

When i turn my ac on it can cool for some times then it's stop and blowing warm air also when the ac is making that change either cooling or stop cooling the engine feels like it holds then goes or lose power i alredy change the compressor can you help me please.

Hi harold1976,

You mean the compressor keeps cutting off?

Get the low and high pressure reading and let us see if we can figure out anything.

Air Conditioning problem
1992 Nissan Sentra 4 cyl Front Wheel Drive Manual

The AC seems to work randomly. When it works, it blows cold. Worked every day for the last two weeks, then yesterday no. When turned on, the compressor engages, slight load on engine, and either blows very cold air, or slightly cool air. I had the system pressured checked, no leaks. Mechanic added more freon, but only took small amount of one can. What else in the AC system can control whether it blows cold or not? A relay? A breaker of some sort?

If the system is full and the compressor is engaging, it may be an issue with the expansion valve.The expansion valve is a temp controlled orifice that is what creates the cold air out of the line pressure.If theblend door (Temp door) works ok, the expansion valve is the only thing left.Your tech should be able to tell by the system pressures when the system is blowing warmer air

[quote:447f6f3427="2CarPros Jack"]If the system is full and the compressor is engaging, it may be an issue with the expansion valve.The expansion valve is a temp controlled orifice that is what creates the cold air out of the line pressure.If theblend door (Temp door) works ok, the expansion valve is the only thing left.Your tech should be able to tell by the system pressures when the system is blowing warmer air[/quote:447f6f3427]
The mechanic seemed more interested in selling me on the conversion idea, especially by the time that I spent the money replacing the old freon.
I don't know if this has any bering on the subject, but when I start the car and turn on the AC, it will either work or not work until the next time I start the car. It never stops working in the middle while I'm driving.

Could very well be the expansion valve.A 134a conversion will be worth it in the long run as well, the refrigerant is less expensive and more readliy available than the R12

[quote:122a802c6a="2CarPros Jack"]Could very well be the expansion valve.A 134a conversion will be worth it in the long run as well, the refrigerant is less expensive and more readliy available than the R12[/quote:122a802c6a]

Do you know how many cans of freon that system would take? Whether I do the conversion, or replace the expansion valve, it looks like big bucks either way.
When it comes to replacing the expansion valve, are we talking complicated enough to diffinently let a mechanic handle it? I guess there is no easy, or most of all inexpensive way out of it.

The exact amount that would be put back in the system would be determined by the system pressures.Since it needs to be converted, I would have a shop do it.The oil needs to be changed to a different kind and the system needs to be vacuumed down to eliminate the moisture that gathers from it being opened

I have a 95 nissan sentra. 1.6 engine, auto. When I am sitting in traffic my air condition does not blow cold air. When I am moving , my ac blows cold air. What is wrong

[quote:54c9026ca3="tedar"]I have a 95 nissan sentra. 1.6 engine, auto. When I am sitting in traffic my air condition does not blow cold air. When I am moving , my ac blows cold air. What is wrong[/quote:54c9026ca3]

Could be low on freon.

I was driving this morning and air conditioning system was working fine. Turned off car for a couple of minutes, then started the car, turned on AC and lights on dashboard for AC system didnt light up and AC didn't work, turned on heater and that didn't work either. What can I do?

Check the fuse and the relay. The fuses are located under the left side of the dash, per the picture attached. The relay is located under the hood on the left side behind the battery.

'96 Nissan Sentra
Engine 1.6, AT, 327K miles (runs great)

I live in a very hot/humid location and my compressor is a new Nissan compressor. The dryer was replaced as well as the expansion valve. The evap coil was cleaned at the same time. Fans always operate when AC is turned on. Problem is that it only blows cold air in the early morning/late night. Daytime it's just cool, but not cold like all other cars are. At idle it goes from cool to almost warm in just a couple of minutes. The AC system doesn't leak and the pressures are good, btw, and the cooling system has never come close to overheating. I cleaned the orig. condenser and it didn't help. I think it simply needs a new condenser, but my friend says if it isn't leaking then the condenser is fine. It has been like this for years with 3 rebuilt compressors and I thought a new compressor would fix the problem, but it didn't. Long freeway drives are a little cooler than city driving and much cooler than at idle. What do you think?

Hi there,

I would check that the heater tap is not leaking, as a quick first up check, and the inside / outside air vents are working as they should.

Mark (mhpautos)

i just bought the car and the compressor would not come on because there was no freon in the car so i went and got some freon and now the a/c compressor comes on and the air blows a little cold but not as cold as i expected do u have any suggestions? thanks

How many ounce's of charge have you put in so far?

25ozs

Did you convert the system from r 12 to r134 charge?

new compressor and added r 134

Hopefully you have a gauge on your charging hose if you do turn on the a/c let it idle and tell me what the pressure is to the low side.

The air conditioner will not work on fan speeds 1 & 2 but works fine on speeds 3 & 4.
What is the problem ?

check blower motor relay, if relay is OK then testing of the a/c control switch is needed. if tests OK suspect faulty blower motor resistor.

My 1994 Nissan Sentra is having an air conditioning issue. It starts out cold, then minutes later it turns cool, then completley stops sending out cool air. Does it need more refrigerant and can I do it myself? I am very mechanically incline if I just get the directions. Thanks.

Hi clay77,

If it is lack of refrigerant, then it would not start cold.

Most probably it is a system problem, clogging somewhere in the system. You need to check the operations pressure.

Air Conditioning problem
1998 Nissan Sentra Front Wheel Drive Manual 159000 miles
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I have the old air condition system that came with this car, but it is know good. The cold air comes in cycles and only when the car is running. The cold air is never ongoing, like in most cars, which is what I would like. I was told because of the engine a 1.6, manual this would be all that I could get unless I upgraded to a better system. What would be suggested to upgrade too, even though the car is a 1998? I can't afford to buy a new car right now, so I am trying to make do with what I have, and the Florida heat without air is getting to me.

Hi there,

The only thing you can do is get a retro fit for a different type of refrigerant gas, but if the A/C has other problems i would be getting a quote to fix that first as just changing the gas will not sole your problem, have this inspected first.

mark (mhpautos)

Makes really loud grinding sounds when turning corners or in reverse. Last night, after pressing as hard as I could on accelerator, the car will only drive 3-5 miles an hour. Also the AC only last 5-10minutes before shutting off & blowing hot air. I'm afraid to drive to mechanic for fear of breakdown. Can u give me an idea of what's wrong?

I feel you may have a transmission/differential problem, this will have to be checked ASAP, the A/C may have a leak and is low on refrigerant, this will cause the system to shut down.