Jason Hughes says the coolant is not even flammable, only if it is distilled.
After we published our article questioning why Business Insider did not present documents to support a serious accusation it made about Tesla, the LA Times published a piece that affirms these documents exist, but also did not post them. While we were trying to contact the National Transportation Safety Board and National Highway Traffic Safety Administration for more details, Jason Hughes had a say in the whole situation. According to the well known Tesla hacker, "this is one of the most ridiculous things I've seen pushed about Tesla in a while."
If you are not following the situation, an article from Linette Lopez at Business Insider said Tesla knew the Model S had a cooling coil issue that could lead to fires, but it sold the car anyway. Two engineering reports would confirm that, but she did not present evidence in her article that these documents actually exist.
On July 1, an article from Russ Mitchell at LA Times said he had access to the same documents. The author also claimed that a federal safety probe would focus on the cooling system of the Model S, which probably had the defective part until 2016.
According to the article, NHTSA said it is "well aware of the reports regarding this issue and will take action if appropriate based upon the facts and data." NTSB said it is about to finish "a Special Investigative Report based upon its investigations of several crashes involving electric vehicles and the resultant battery fires/thermal events.” The NTSB confirmed that statement to InsideEVs.
There are no reports of fires in crashes happening due to the cooling coil issue Business Insider described. We asked NTSB about that and Christopher T. O'Neil, its chief of media relations, said he could not discuss any documents at this point because the SIR is still ongoing. The results will be presented in the Fall of 2020.
We also asked NTSB if there were any chance that the FBI would be involved in the investigation. We wanted to confirm if hiding a safety defect is a crime.
According to O'Neil, "if any NTSB investigation reveals evidence of a crime or violation of a regulation, that information is shared with the appropriate law enforcement agency and/or regulatory agency." In this case, that agency would be NHTSA.
We also got in touch with NHTSA. While we were waiting for NHTSA to reply, Jason Hughes, from HSR Motors, tweeted about the situation with the knowledge he has accumulated from dismantling Tesla over many years.
Soon after we saw the tweet, we got in touch with him to learn more about what he meant.
"The funniest thing about this is that the coolant is not even remotely flammable. If you distill it, sure, it has components that can be. But a coolant leak is not going to cause a fire."
There's more to this than just what composes the coolant. Hughes sent us pictures and explained what that coolant loop is, as well as the end pieces mentioned by Business Insider. The place in which the leak could happen would not allow for the coolant to reach the cells, according to Hughes.
"Even if they did leak at the loop end pieces – I've never even seen one out of thousands leak – this would drip onto the bottom casing of the pack. That's several millimeters below the lowest point of the battery module itself. There would be no contact between it and the cells. Even if it leaked into the plastic tray under the module, it would have to basically fill it to get anywhere near the cells."
You can see the end loop pieces right above and on the other pictures posted before it. We had the impression it was connected to a cooling coil, considering the description given on the articles we already mentioned. Hughes corrected that idea and said the end pieces are connected to locking fittings with rubber seals, which you can check right below.
The coil, or loop, is the ribbon-like aluminum component that touches all the cells. You can see it below, on the left side of the dismantled module. It is similar to a white ribbon.
Hughes has seen many accidents with Teslas – including one in which, unfortunately, he was affected – and he gave us his perspective on if something like this could happen, which NTSB will certainly investigate.
"I've seen accident vehicles where a side impact ruptured the main coolant line on a side, leaking it all into the pack. Even that much coolant wasn't enough to actually even touch the cells. This is just so much of a stretch it's baffling. Interestingly, similar coolant is used in some fire sprinkler systems."
If there is no risk of fire involved, does it mean the cooling coil did not present issues? The Tesla hacker does not spare words when Tesla does not act right, such as when the company cut fast charging from salvaged EVs. But he also does not stay silent when something is unfair, as in the sudden unintended acceleration claims. This is his take on the documents Business Insider and LA Times claim to have checked.
"I could definitely see Tesla having R&D issues with the coolant loops initially. They're new tech, nothing like it out there. Seems certain there would be some R&D pains there. I feel like the issues in whatever data these news agencies are getting their hands on is reflecting that – not leaky loops being put into production cars. I've torn down packs from several early Signature vehicles. If anything, it seems far more human attention was paid to aspects of those cars than later ones.
That said, nothing is 100 percent perfect. I'm sure there's probably a car or two out there that have a coolant leak somewhere. But even if that's the case, this just doesn't translate to battery fire. That's a jump in logic that doesn't make a lot of sense."
We wish Tesla had the same willingness to answer and clarify such allegations as Hughes has. If these documents exist and are real, the company should explain in which context these coolant leaks happened. If they do not pose a fire risk, why hasn't Tesla defended itself? NHTSA and NTSB may have more information for us soon. What is fundamental is to get the facts straight, and Hughes may have made an invaluable contribution to that.