2 units in one week (Austria & Slovenia) – Both units failed shortly after being “repaired” using a coolant-delete workaround. This is exactly the reason why we never adopted that method in the last 4 years. Instead, we developed a complete, engineering-grade repair process and the LDU Holy Grail e-Drive KIT, which has proven itself with over 800,000 km of real-world road testing.
One failed motor arrived from Slovakia immediately after a coolant-delete repair, the other through Slovenia. In full transparency, we must again warn the community: avoid coolant delete.
Not only is it a more expensive service path in the long run, but there is a permanent, long-life solution—proper rotor machining combined with a graphite mechanical seal.
The two recent cases show the risks clearly:
• one unit suffered inverter overheating while driving,
• the other experienced stator overheating and insulation collapse, even though no coolant intrusion was present.
We are also seeing a growing number of similar complaints from colleagues who perform coolant-delete repairs, many of whom are now forced to install replacement LDUs to customers at their own cost.
Of course, even with our solution, out of 50 LDUs one may occasionally arrive with a new, unrelated issue—but we have never had a single case of overheating or coolant intrusion with our repair method.
The core problem with coolant delete is that when new damage appears due to overheating, the stator must be replaced, and the coolant manifold is often ruined because the pipe is cut. In many cases, the rotor shaft is shortened as well. This means that an official EVC Reman becomes significantly more expensive, as one or two major components must be replaced.
Avoid coolant delete. Do it once — do it properly.
*in nordic cold countries C-D might work
Book your appointment and save time and money:
HR: evclinic.hr
DE: evclinic.de
Technical note for the community:
Removing the rotor cooling circuit means the rotor has no path to release its heat. The trapped heat accumulates in the air gap and transfers directly into the stator, bearings, and especially the exposed end-windings in the center of the stator. Those windings have no active cooling, so their insulation darkens, becomes brittle, and develops micro-cracks — a pattern we repeatedly see on coolant-delete failures.
That heat also migrates through the rotor shaft into the bearing seats. Even a small temperature increase drastically shortens bearing and grease life, which is why coolant-delete units often show early bearing noise, vibration, or thermal discoloration.
Another critical issue: the LDU cooling system is engineered as a single, balanced hydraulic circuit. Blocking only the rotor branch disrupts internal pressure and flow distribution. In practice, this often causes both the inverter and stator to run hotter than before, even when no coolant intrusion is present. Weeks or months later, this imbalance leads to inverter derating, stator overheating, insulation collapse, or sudden shutdown under load — exactly what we see in the recent cases.
This is why restoring the rotor properly, machining the sealing surface, and using the correct graphite mechanical seal remains the only reliable long-term solution.
Our longterm sustainable solution is:
https://evclinic.hr/hr/product/evc-tesla-holy-grail-ldu-edrive-kit/?v=c4cc1a1ba567
It made 800,000km so far at the moment during post editing, read the post below:
