mi car just started to heat up yesterday and just cool air will come out of the ac, i took it to the mechanic that did the work on before because he just change the thermostat no more that 2 weeks, it seen that the thermostat was bad again, he change again but no heat will come off ac, will idle the car,and after 3 hrs of try to get the heat to work it seen that it did, just went a was taken it home the car started to heat again and no heater and stuck any suggestion guys

 

the mechanic was supposed to get it fixed, he hasn't.

Take it back and have him FIX IT.



Sounds to me like the system wasn't properly bled.

 

did he use OEM thermostat? 99% of the time no heat means the cooling system needs to be bled correctly...

 

i think the first he bought it in oreallys and i dont know were he got the second one, and yeah he has it right that why im because i love my max and i not drive it, yeah i was there yesterday with him for 3 hrs as far i know he did every we try some suggestions from the forum to get the heat to work, we bled itwe use around 2 gallon of coolant and i know it not leaking anywhere we check everything, but after it seen that it was working , i drove home i notice that the needle started to rise good thing that it was cold and didnt allow to overheat the engine all the way, maybe i do need a oem thermostat.

 

yes you do need OEM thermostat.

 

How is the blend door motor ? or the controls to it ?

 

I've noticed that if you sit in the driveway on a cold day, you will never get heat. You actually have to drive the car. Same for the A/C. If it is a **** of a hot day and you pull over to the side of the road, you won't get cool air if you sit too long

 

if the system is bled, the heater core is probably plugged up, you can try flushing out the system with a pressure washer, but you probably need a new heater core

the heater core is a big job, gotta take out the whole dash etc

 

If you don't get a/c while sitting you have a problem with your a/c - most likely one of your fans is bad.

I live in Florida and frequently sit idling in my car while on the phone. My a/c works just fine.

 

C'mon man. Use some punctuation.

As for your problem . . . almost certainly he didn't bleed the system properly. You can do it yourself.

Open the radiator cap and check the coolant level (my bet is that when you open the cap, the radiator will not be full). Fill with 50/50 mix of coolant and water.

Leave the cap OFF, turn the heat on full blast and run the car until it gets to normal operating temp. Rev the car just a little to force air out. If you rev too much you will lose coolant. You can also squeeze the hose on the drivers side to get out any air bubbles. Again do it carefully so you don't lose too much coolant. Let the car cool.

Repeat until you can no longer add coolant.

 

This is true, in both the Max and the Z this happens to me.

 

I can sit parked and soon as the coolant temp gauge starts to climb, I'll have heat. But I do notice the air isn't as warm as it is if you get the engine into the 4-5k RPM range, at least once while driving.

 

The key to bleeding the Maxima (and most other cars) is to have the car at an incline (either find a steep drive way or jack the front of the car up). Put car into on position (but don't crank), set climate control to MAX heat, wait 10 seconds then turn the car off. Open the rad cap (ensure the motor has cooled down before doing this), start car and let it warm up (15-20 mins if its cold), add coolant as the level drops.

Let it run for a while, rev a tad bit once in a while, make sure blower is on high and heat is on hottest setting. Eventually it should start to warm up.

OEM thermostat or aftermarket thermostat, heat should still work. What I found with aftermarket thermostat was that it was not opening up at the factory spec temp.

 

Just a thought from another angle...

Do you have the electronic climate control in your car? You may be barking up the wrong tree if so.

Last year around this time, the cabin temp sensor in my I30 failed, and for some reason decided that it was 135 degrees inside my car and was constantly trying to cool the car down. (like, even if I set it at 85, it would crank the AC since 85 is cooler than 135.)