My 2005 Kia Sorento makes a loud shreeching sound when I turn on the airconditioner it comes and goes as the compressor kicks in and out

Does it tick with just the ignition on but engine not running? if yes its a relay or solenoid trying to kick in. if only with engine running and its a deisel could be the injector relays. identify where the sound is coming from. if petrol could be the pump. you need to identify where the noise is coming from for a better diagnoses.

The only time i have encountered this problem it turned out to be a cracked fan wheel in the blower. fooled me until the fanwheel disengrated and locked up the blower motor.. could be trash in the blower too like leaves, plastic bag etc.

it could be a lifter or a sticky injector I would say to see your kia dealer for issues or recalls they are good about following thru with issues

pag oil for the AC compressor comes in but one weight.

Sounds like you have either a loose, worn or streched fan/serpentine belt. The lost likely reason you don't hear it all the time is the fact that there is not as much of a pull on it. When you first start the car your alternator will demand more out of it and the same goes for your air conditioner compressor when you turn it on. I would check the belt to see if it has any cracks or if it is loose. I hope this helps you and good luck.

Sounds like a vacuum leak. A lot of the stuff under your hood runs off of vacuum that your motor provides. Your brakes are no different. Your motor probably has enough vacuum to run fine but when you hit the brakes its just too much. I wouldn't push my luck. A car with a habit like that could make an accident real quick.

the lock or mechanisim is stiff, get some wd40 and spray all around the lock and around the mechanism dont be shy with it.

If the problem persists then the motor for the central locking is about to go, this will need to be replaced as they rarely are fixable.

Hope this helps

Reghards

Dan

It is either the tesnioner or the belt....easy way to find out is to spray the pulley that has no grooves....that's the tensioner. Spray it with WD-40 or equivalent, in the middle of the pulley. That is the bearing housing. Spray only that first. Start the motor...if it goes away, then you have found your problem. Try not to spray the belt.

If it still squeals, spray the belt with the engine running. If it squeals, replace the belt.

Has anything been done to the motor recenlty? If so, one of the pulleys may be a little off-centered.

Let me know what you find.

Sound like you have a bad starter solenoid or starter relay

Check the water coolant level because some of the hot water goes into the heater radiator behind the dash. Seems you have air in the system.