Grandma had for yearss but never used it after minor accident rear passenger side. Bought last week at 74,000, but having problems with the heater not working in car and the fans are not moving, even after the Nissan bypass function check, the fan still don’t work. At first thought was issue with gasket but now have gotten to figure out this issue after process of elimination. Possible connectors not connected or thermostat or fan motor fail and need new fan assembly. I’m not sure what to do or where to go now. (These issues were not faced during purchase of car). The video was from the night before, but everything I figured out was after the video, which is the morning following. Honestly, I just want to figure it out and get to fix it if I could but if needs new fan assembly or anything big, I’m guessing a mechanic. My first car and just want to get back on road. I spent all day trying to diagnose the car

 

It looks like your coolant is boiling and it is obviously overheating. Did coolant temp gauge peg or did you shut it down before that happened?

I'm not sure what the "Nissan bypass function check" is.

Seems to me that if the fans aren't moving and pulling air through the radiator, it is causing the engine to overheat. Probably due to failed fan motors, disconnected fan motors, or maybe some electrical fault causing the fans to not receive the proper signal to start spinning. Start with the easiest to confirm that the fans are receiving power at the connectors and then go from there. You mention process of elimination, but you haven't explained what you've actually eliminated.

If it is the fan motors, you don't need to replace the entire fan assembly. Fan motors are sold individually. This can be done with basic hand tools.

Congrats on your first car.

 

I was talking about the IPDM active test. But thank you hella brother. I’m going to start again tomorrow and take a look at the suggestions you gave me. Hopefully it’s nothing major. And thank you man, I can’t wait to get her back on the road yk? I will keep this thread updated by tomorrow night.

Happy Holidays!!

 

If the heater is not working, then you have air trapped in the heater core. There could be multiple causes for this state, but the two most probably causes are 1) The coolant level is dropping due to a leak somewhere, 2) Someone flushed/refilled the cooling system and didn't follow the FSM refill/bleed procedure (very common mistake). I watched your short video clip of the overflow bottle boiling/hissing/steaming and I think this problem might be more severe than I initially thought.

Here's what I believe is happening (two possibilities)...
1) Some air is trapped in the heater core, the thermostat is working, but your radiator fans are not kicking on when they should be. Under extended operation of the engine at low speeds (think stop and go traffic or driving in urban areas with lots of stop and go), the engine will start to overheat due to a lack of airflow over the radiator.
2) There's "some" air trapped in the heater core, however the thermostat is stuck closed and causing an overheat scenario. I think it's worth noting that if the thermostat was stuck closed, the radiator fans should still kick on if a good temp reading is being sent to the ECU. The fans should also stay on if the coolant temp doesn't drop below 195*F.
3) Someone touched the cooling system and did not properly refill/bleed it. There's a major amount of air trapped in the engine + heater core which is preventing the thermostat from opening and coolant from circulating via the water pump (air locked). Driving the vehicle like this will for sure overheat the engine and blow the head gaskets or worse.

Thermostat operation simple check:
Let the engine idle/warm-up for a few minutes. Grab the upper radiator hose it should be "hot" or getting "hot". Now grab the lower radiator hose (best done from underneath), always be mindful of sticking your hands/arms around those electric fans and accessory belts! If the thermostat is still closed, then the lower hose should be noticeably cooler. If the thermostat is opening as designed, then the two hoses (both upper and lower) should be equally "hot" to the touch.

Fan operation check:
The radiator fans won't kick on unless your engine coolant reaches operating temps (somewhere around 210*F, then cycles off around 195*F). This is by design to speed up the warm up process of the engine, also the thermostat is closed when cold, so you don't have coolant flowing through the radiator, meaning there's no point in running the fans unless your A/C is on. If you have trapped air in the system, then it's possible your coolant temperature sensor is not sending a good reading to the ECU and thus not kicking on the fans. A simple check for fan motor operation is to turn on the A/C (full cold). Both fan motors should immediately kick on (whether the engine is hot or cold). If the fans DO NOT kick on, then you have an electrical fault. Most likely a failed fan relay or fuse. In rare cases, you can have a fan motor fail, but these don't fail in pairs. I have never seen both fan motors fail together without root cause being upstream electrical problem (relay or fuse).

So...quick recap...
1) Make sure your electric radiator fans are working by turning on your A/C FULL COLD. If both fans do not cycle ON with the A/C engaged, then you need to troubleshoot the Fan Circuit (check fuses/relays).
2) Check that your thermostat is opening and allowing the coolant to flow through the radiator.
3) Re-bleed the cooling system following the FSM procedure. There is a air bleed valve on one of the heater hoses next to the battery box. This process requires the use of a spill free funnel and revving the engine periodically to push out the trapped air.

If this sounds like more than you can handle, then I would have the vehicle towed to a professional for diagnostics and repair. From what I can tell so far with the info given, the cost of repair should be minimal, but if you severely overheat the engine, then the cost of repair would pretty much total out the vehicle unless it's in pristine condition.
Good Luck!
-Icer