So I just swapped my old engine that had rod knock for another new VQ35DE. So it’s all swapped in and I could get it started after some coaxing, but it always goes into limp mode and spits the code P1217. I changed the engine coolant temp sensor and still no luck. I’ve reset the ECU more times than I could count and nothing helps. The thing is, I never even got it hot enough yet for it to say the engine its overheating. So I have no clue what’s going on. I was thinking of replacing the thermostat but really I can’t see that doing anything since there is no sensor there. Can anyone help? Thanks.

Car -
2003 G35 Coupe

I attached a video of the car being limited to 1750 rpm
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https://streamable.com/1ea5km

 

Is the car actually overheating on the instrument cluster temp gauge?

If so there's likely air trapped in the system, especially if you added the coolant too fast, didn't use the air purge on the heater core hose, etc. These cars can be difficult to fill, personally I use a coolant vacuum bleeder kit.

The main sign that you have air in the system is the heater won't blow hot air, if you ARE blowing hot air and still overheating then you might not be holding coolant pressure. Coolant pressure test to make sure it holds around 12psi.

Also, in that vid it sounds like you're running on 5 cylinders.

 

having same stupid issue swapped a jdm motor into my 2003 infiniti g35 6mtused orignial wire harness and im getting overheating code p1217, car turns on but doesnt rev past 2,500 rpm. changed a ton of sensors and checked grounds not sure what it could be reset the ecu so many times im so lost at this point