2005 Nissan Sentra, AC blowing hot & engine overheating

Sounds like the heater - ac door actuator is not working. This part would need to be replaced, it's not repairable.

Are you talking about the engine cooling system or a problem with your Auto A/C?

Maybe your radiator is clogged.

has to be air bound.with vehicle running but before it gets too hot remove outlet hose from heater core at bulkhead.wait for consistant waterflow out of hose then reinstall and top up system.now the bad ....where did the air come from?these engines are becoming notorious for head gasket failure.does it ever miss and run rough for fist few seconnds after a cold start?if so this is probably your issue.

i have a 2005 1.8 nissan sentra.i rplaced the radiator becuause it was leaking.so when i did i took it for a test drive and the needle went to hot then back down to middle ways between the C & H BACK IN FORTH.so i replaced the thermostat. now as far as i can tell it is staying in the middle of C & H. i can't feel no water though cerulating through the top or bottom hose of the radiator. so now that i told you what i done so far my question is???? ( my heater is not working in the car it is blowing out cold air & i left the car runnng for about 45 min. even took it up and down the road.still cold air.what do you think i need to do?????????? )

My 2005 Nissan Sentra 1.8s with 55,000 mi. blows cold air from the heater. Coolant not circulating in engine. Lower hose stays cool to touch. Both heater hoses cold. Changed thermostat - didn't fix it. Coolant not leaking or dirty. None in oil - no oil in radiator. Changed worn water pump belt - pump spins freely with no noise or resistance. Cooling fans come on after warm-up. Temperature gauge stays in normal range then jumps to hot and back again. Coolant good to 10 below - didn't freeze here yet. No other problems or repairs to car. Afraid to drive and make worse. Help!

Not generally, unless the engine's been run hot, if even only for a moment. If the head gasket is blown prepare for major out of pocket expenses because if the engine overheated it will bend every valve and usually warp the head beyond repair. I honestly hope this is not your problem, it's an extremely expensive fix. Hope this helps, good luck!

If all of the things you replaced are working fine I am going to say double check the thermostat. Also make sure your fan is engaging at temp. You cam check by running till warm and then running the AC. If the car does not overheat with the AC on then your fan is not running under normal conditions (with AC off) This can be caused by a couple of different things depending on how the fan is set up. I am not a nissan expert

My 2005 Nissan Sentra 1.8s with 55,000 mi. blows cold air from the heater. Coolant not circulating in engine. Lower hose stays cool to touch. Both heater hoses cold. Changed thermostat - didn't fix it. Coolant not leaking or dirty. None in oil - no oil in radiator. Changed worn water pump belt - pump spins freely with no noise or resistance. Cooling fans come on after warm-up. Temperature gauge stays in normal range then jumps to hot and back again. Coolant good to 10 below - didn't freeze here yet. No other problems or repairs to car. Afraid to drive and make worse. Help!

My 05 sentra with 79k miles heat will warm up and then get cold after a mile of driving, we have tried to get the air pocket out, the mechanic stated he thought it could be a blown head gasket, another mechanic said it was a bad heater core. Any advice would be appreciated.