is it ok to put my 1999 nissan car ac on for long time?or should i switch it on/off intermittently?

Question

Also is it possible that when i drive the car i get some kind of pull when the car changes speed at 25,30 or 35(usually low speeds) that this is the result of gear change(automatic transmission).but can it be like the car was manual first and then changed to automatic or maybe engine shows the gear change even though its automatic?
i also passed my nj state inspection today without any problems,so what r the things that i should feel free for my car now.i know my car makes brake noise but then it passed insp in 5 min so i dont know if its a big concern anymore!thanks!!

i dont really think that the car has 'steering pull' rather its the car like when i change from 20 mph -30 mph the car seems like it has to do more work and kind of stops for 1/10 th of sec and then jumps on 30 with giving me a slight forward force..

Answer 1

Your A/C has a thermostat inside the plenum that controls the temperature inside the car according to your setting and it will cycle the A/C compressor clutch on and off as you drive. Not much different than the A/C in your house.

Most steering "pulling" is caused by either low tire pressure on one side of the car or the alignment is slightly off or you might have some tire tread wear that is excessive on one tire in comparison to the tire on the opposite side. Make sure your tire pressure is the same in all four tires. Make sure the tread depth and wear is even on at least the two (front) drive tires. If the two front tires have significantly different tread depths, one tire will actually turn faster that the other. If the tires are OK, then you can have an alignment done and this should take care of the "pulling".

Brakes will squeek or make noise for a variety of reasons but the most common is vibration of the pads against the rotors or drums while braking. This is remedied by using the anti-squeek compounds when installing the pads and using silicone grease on the caliper pins and the drum brake backings or rests. Too many shops and new car manufacturers neglect to use these "compounds" when installing new brakes.

If you passed inspection, you are safe so enjoy your ride. If it bothers you, most shops will do free brake inspections and let you know what they recommend.

Good Luck!

Answer 2

1) A/C- just leave it on when you need it and set the temperature so it's comfortable. The A/C compressor switches itself on & off as needed to maintain the temperature.

2) Sounds like you're just feeling the transmission shifting gears. Perfectly normal.

3) Some brake noise CAN be OK. If it's just a light 'squeek' when gently pressing the pedal then it's probably not a concern. That's probably just a vibration in the pads. It can be cured by removing the pads and installing a shim and some brake-quieting compund behind the pads, but it's not a problem if you can ignore it. If it's a constant noise, or if it turns into a 'metal grinding' noise when you push the pedal, then you need to get them fixed right away. Either way, it won't hurt to get it inspected by a reputable brake repair shop.

Answer 3

The AC cycles itself automatically, so you can leave it on all the time.