Public Service Announcement, All ERay Buyers!

I was checking the oil in my just-delivered Corvette ERay, and while I was in there, I decided to look at my High Voltage Battery System Coolant Reservoir. This is the coolant system that's partially responsible for cooling the 300-volt battery pack, located in the center tunnel, which powers the electric motor that drives the front wheels, making the ERay all-wheel drive. The cap on my ERay was loose (not screwed on properly) and vibrating! It was vibrating, of course, because the V8 engine was running, which is how you check the oil in C8 Corvettes with a dry-sump oiling system. After alerting another ERay buyer whose car had been delivered at the same time, he discovered that the same cap on his ERay was not screwed on tightly either! His is a Coupe, and mine is a Convertible, but the cap is in the same location (just under an engine cover in mine, as seen below).

When I discovered the cap in this condition, I reflexively tightened it because I thought it shouldn't be loose. I didn't crank on it hard, but I did turn it clockwise by hand to snug it up. After doing that, I had second thoughts, however. Since I hadn't actually taken the cap off the neck of the reservoir, I didn't know what was inside there, and I wondered if for some unimaginable reason the cap was supposed to be that loose. This is a brand new, expensive car, so doubts crept into my mind about what I'd just done, and I decided I should take the cap back off and inspect everything more carefully, but there was a problem. When I tried to do that, the cap just clicked, and it wouldn't come loose, as seen in this video!

I have the solution to that problem, but the main point is that this is a Public Service Announcement to all ERay buyers to check this cap on their cars! I don't even want to think about the damage that could be caused if this cap somehow vibrated enough to come off the filler neck and fell down into the engine compartment.

Besides that — as you can see in the photos — it's a 5-PSI system, and with a loose cap, I drove around for 100+ miles at 0 PSI!

As seen in the Owner's Manual photo above, this is a dealer maintenance item, and directions about how to remove the cap that I'll show next are not in the Owner's Manual, so if you do any of the following, you're responsible for your own actions and your own car. I'm providing this information for educational purposes only. I don't know what reference material Chevrolet dealerships have on this matter, but when I set up an appointment and brought my ERay to an experienced Corvette service department, the Service Consultant and the Corvette technician didn't know how to remove the cap either. This being such a new model — and the first Performance Hybrid Corvette — that's understandable, but the cap should not have been loose in the first place!

Locate the slot in the top part of the cap, near one side, and insert the screwdriver gently into that slot (vertically). Now, turn the cap counterclockwise with the screwdriver inserted until you find the matching notch in the bottom part of the cap. You'll be able to feel the screwdriver go in a little further. After that, when you continue to loosen the cap, it won't click because it'll be pulling the bottom part with it. It'll actually be loosening the cap. When you come to the tube on the right side of the filler neck, you may need to pull your screwdriver up and out a little bit to allow it to pass. Once on the other side, continue to turn the cap counterclockwise. I needed to get past that little tube twice before my cap came all the way off, but it wasn't difficult.

Here's what the cap looks like and what the inside of the High Voltage Battery System Coolant Reservoir neck on an ERay looks like. You may be able to see what looks to me like a Max Fill line for the coolant, which is clearly visible. I'm not sure what the round dark spot is at the bottom of the reservoir in the third photo, but I'm quite sure it's normal (please inform me if you know differently), and any seams in the plastic tank that look like cracks, really are just seams. I inspected it closely.

One other thing to note is that once you're done (if you've taken it upon yourself to do any of this), make sure you properly seat the rubber access panel back into place. Those access panels — or "plugs" as the Owner's Manual calls them (including the one for the oil cap and dipstick on the passenger side) — have been known to interfere with the convertible top sensors right above them and cause a malfunction. You wouldn't want to get caught in the rain a long way from home and not be able to put up your top or have the car be speed-limited to 25 mph, if the top malfunctioned in some other catastrophic way, not fully up or fully down. It could take a long time to get back home!

This is the way it should look on a Convertible when you're all done, along with the warning about these access panels, which is located near the oil fill and dipstick panel.