Table 1 shows one common engine and engine cooling related problems of the 2017 Tesla Model S.
| Problem Category | Number of Problems |
|---|---|
| Engine And Engine Cooling problems |
I am reporting a suspected defect in the rear large drive unit (ldu) of my vehicle, a 2017 Tesla Model S p100d with approximately 40,815 miles. The component involved is the rear drive unit’s rotor seal, which is known to allow engine coolant to leak into the motor. The concern is safety-related. Tesla coolant is electrically conductive and can form a conduction path inside the motor and inverter, and coolant can also damage bearings. Once coolant enters the drive unit, the result can be electrical faults, loss of drive power. If the drive unit fails while the vehicle is moving, especially at highway speeds, it could cause a sudden loss of propulsion or reduced braking-related regeneration, which could lead to a crash. Other owners have reported this kind of failure without warning. I am concerned about both the loss of propulsion and the electrical hazard of coolant in high-voltage components. I have not had a drive unit failure. I have received a quote of approximately $1,500 from an independent shop to apply a preventive coolant bypass in which I am not confident that an aftermarket bypass will fully prevent the failure, and I have not seen independent long-term data on its results. I have was told that a drive unit replacement, if the leak progresses, could cost $5,000 or more. A Tesla service advisor told me on earlier in 2026 when they inspected my Tesla that Tesla will only address this issue if the drive unit has already failed, and that there is no preventive repair available for vehicles that have not failed. I believe this is a design defect in the rear large drive unit. Tesla has replaced failed units under warranty with a revised “u” drive unit that blocks coolant from entering the rotor. I request that NHTSA investigate whether the original rotor seal design is a safety defect and whether the revised design should be offered to owners of affected vehicles, including those whose drive units have not yet failed.
This is an update to NHTSA complaint #xxx with new safety information. My 2017 Tesla Model S (VIN [xxx] ) has a confirmed high-voltage isolation fault. Tesla replaced the rear drive unit under warranty, but Tesla’s own technician notes now state: “there is a risk of isolation alerts reoccurring during regular driving, use of hvac system, or DC charging. ” “vehicle may power off due to isolation faults when the air conditioning is used. ” this is Tesla acknowledging in writing that the vehicle may shut off during normal driving, even after repair. This presents a serious crash risk. The original failure occurred during supercharging, with warnings including: • “electrical system power reduced — vehicle may shut down unexpectedly” • “vehicle may not restart” • “air conditioning reduced — DC charging reduced” Tesla reproduced the isolation fault during diagnosis. Even after replacing the rear drive unit, Tesla documented that the isolation defect still exists and prevents a battery health check or DC fast-charge validation. Tesla has attempted to return the vehicle to me in this unsafe condition, while admitting the defect persists. They also stated they may charge storage fees or tow the vehicle, despite the unresolved safety issue. The defect affects the hv bus and can cause loss of propulsion, shutdown during driving, and charging failure. Tesla has not provided numeric test results (megohm isolation readings, insulation tests, or validation data) proving the vehicle is safe. This is an ongoing, manufacturer-confirmed hv isolation defect that can lead to sudden power loss. I request NHTSA review Tesla’s handling of this issue and link this filing to case #xxx. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).
While attempting to park the car in a parking space the car accelerated on it's own and crashed over a small concrete retaining wall and crashed into another vehicle. My car and the car that was struck were totaled.
2017 Tesla Model S started to accelerate on its own over 100 mph, when traveling on highway around 70 mph, without autopilot engaged. As soon as it started to accelerate, the car took control over the steering wheel and drove into the guardrail on the left of the lane, then quickly steered to the right lanes and steered to the left again. Slammed on the brake but did not work at all, and steering wheel did not respond. The car completely took control over traveling over 100 mph going zig-zag on three lane highway, finally came to a stop after hitting number of trees in the woods on the right side of the highway. The car is completely totaled.