Cooling
3 article(s) on «Cooling». Most serious issues first.
Model S/X: LDU problems (the large rear motor), seal leak and failure
A typical 2012-2020 defect: coolant leaks past the rotor seal into the stator/inverter, an insulation fault (BMS_w172) follows, and the motor dies. Tesla itself dropped rotor cooling in the revision-U motor. What to check, and repair options from $50 DIY to a $7000 reman.
Radiator health in Service Mode: where the percentage comes from and why it falls
Firmware from the 2026.20.* branch added a radiator health percentage to Service Mode. In the summer of 2026 it sagged across the fleet: 79% on a refreshed Model 3, 83%, 76%, and for one owner 100% turned into 65% in three weeks. The number comes back to 100 neither after cleaning the stack nor after fitting a new radiator. What sits behind it, and when it really is about dirt.
Coolant bleeding: removing air after repair
After coolant system repair the coolant doesn't circulate due to an air pocket. How to bleed it via Service Mode, and why after removing the HV battery the system may only be refilled under vacuum, with the procedure per the Tesla manual (Coolant Fill/Drain, vacuum, Coolant Air Purge, top up to norm).