Eliminating the Eyesore. Mishimoto 2016 Camaro Expansion Tank R&D, Part 1: Stock Tank and Initial Design

While we were deep in development of various new components for the 2016 Camaro, we received numerous requests for a replacement for the coolant expansion tank. While an upgrade here won’t net any horsepower gains or drop fluid temperatures, a replacement tank can certainly improve the appearance of your engine bay.

Since we are experts in producing innovative aluminum replacement expansion tanks, we decided to tackle the Camaro unit as one of our new projects.

Stock 2016 Camaro Expansion Tank

The stock 2016 Camaro expansion tank is quite a unique piece. GM has combined the expansion tank and overflow tank into one unit. If you’ve ever peeked under the hood of a Cadillac ATS, this unit should look familiar.

Before designing our own aluminum counterpart, we needed to inspect the stock 2016 Camaro parts and evaluate each of the features.

Stock 2016 Camaro coolant expansion tank
Stock 2016 Camaro coolant expansion tank

The split tank design is pretty slick and reduces the number of areas for potential coolant leaks. The upper portion of the unit is the pressurized chamber, which attaches to the rest of the cooling system. The cap regulates internal pressure by pulling fluid from the overflow cavity when fluid levels are low and pushing fluid back into the overflow portion when temperatures and pressure rise excessively. The small tube you see running vertically connects from the radiator cap housing down to the base of the overflow cavity.

Stock 2016 Camaro coolant expansion tank
Stock 2016 Camaro coolant expansion tank

The rear portion of the 2016 Camaro coolant expansion tank reveals a few more features. We see the two lower mounting points that utilize a rubber bushing for flex. The two arrows in the image above are pointing to bleed holes in the upper portion of the overflow cavity. This is where air will purge from the cooling system during filling.

The rear portion of the tank is also a busy area and features a coolant line port and the fill tube for coolant.

Stock 2016 Camaro coolant expansion tank
Stock 2016 Camaro coolant expansion tank

Below is an image of what Camaro owners see under the hood.


The engine bay on this new model is quite sleek, yet most components are black and subtle. The standout feature is the pink coolant tank, which gets its color from the coolant inside. An aluminum counterpart in either a polished or black finish will be a bit more presentable for folks who are style-conscious.

Mishimoto Design

We need to incorporate many of these features into our tank design.

  • Dual cavities for both expansion and overflow
  • Stock cap fill neck
  • Air purge ports
  • Fluid level indicator for overflow tank
  • Fluid level indicator for expansion tank
  • Appropriate connection between cavities
  • All mounting points
  • All ports for coolant lines

This is a tall order for an expansion tank and will likely be one of our more intricate designs.

3D Models

With all measurements from the stock tank on hand, our engineering team set to work designing our 3D model in Solidworks. Check out a few shots from our early iteration.

Mishimoto 2016 Camaro expansion tank model
Mishimoto 2016 Camaro expansion tank model

Here you can see our tank beginning to take shape. The overflow portion of the tank features a machined fill neck, a glass sight tube to check fluid level, and a port running into the overflow cavity.

2016 Camaro parts
2016 Camaro parts
2016 Camaro parts
2016 Camaro parts

The front side of the 2016 Camaro expansion tank model shows some branding ideas we are working on. You can also see this branding on the front port that runs to the thermostat housing.

Get a closer look at our initial model below! Use your mouse to spin the model and check out the different features on our first iteration.

Mishimoto Camaro Expansion Tank Prototype
by mishimoto
on Sketchfab

Coming Up – 3D-Printed Prototypes

Once we have a couple designs solidified, we will be using our 3D printer to create some prototypes. Check back next time for a neat update. Let us know if you would like to see any additional features or finishes for our project!

Check out our blog for updates on other upcoming 2016 Camaro parts.

Thanks for reading!