2017 T6 - Excessive coolant usage and "Engine System Reduced Performance'

I have had my 2017 T6 Inscription with Polestar Performance Package for under one year and have just over 30,000 miles on it. During that period of time I have had the following issues:

  • Replenished coolant several times totaling almost 2 gallons. There has never been any sign of engine fluids on parking surfaces. The dealership has done a pressure testing and said everything was fine.

  • Engine fan runs fast and loud like a jet engine after climbing a hill to my parents' home and turning off vehicle upon arrival

  • Recently received "Engine System Reduced Performance" message with the vehicle barely able to move and coming to a stop
Has anyone encountered any of the above issues?

No. You are the first one I know that has been on here reporting issues like that.

It has to be a leaky gasket or a crack that opens up during load. It wouldn't show during a normal pressure test. The engine is defiantly consuming the coolant somewhere.

Has your dealer checked the transmission fluid? most modern cars utilize the lower part of the radiator for a transmission cooler. there was quite a mess for Nissan a few years ago as the barrier between engine coolant and the transmission oil cooler got compromised on many vehicles. The two fluids mixed and nobody knew it for a long time. Then all sorts of issues started to manifest. One was coolant consumption.

Best of luck and keep us informed on what they find as the issue.

Rob: As it turns out, there indeed was a leak when the car was under load as you mentioned. When sitting still the dealer found nothing. They subsequently identified the leak when the car was in motion. Good call!!!