E46 3-Series Silicone Radiator Hose R&D!

E46 3-Series Silicone Radiator Hose R&D!

Interested in purchasing our E46 silicone radiator hose kit? Check out our product page linked below!

Mishimoto BMW E46 Non-M Silicone Radiator Hose Kit!

The E46 BMW has been the focus for a ton of product development here at Mishimoto. Recent projects include the Mishimoto Performance Air Intake, Aluminum Radiator, and Aluminum Expansion Tank. To continue our pursuit of supplying a full cooling solution for the 3-series, we also tackled a set of radiator hoses for this model. In typical Mishimoto fashion, we will be looking to improve the durability of the stock design.

Stock Hose Setup

The stock BMW E46 radiator hose system is unique, mostly due to the inclusion of quick-disconnect fittings at each mating point. Take a look at the stock hoses pulled from our test vehicle during radiator testing and development.

Stock E46 radiator hoses
Stock E46 radiator hoses

The upper hose features two quick-connect ports that mate to the radiator expansion tank. In addition, this piece features a bleeder screw that makes removing air from the system quite easy.

The E46 lower radiator hose is slightly less complex, though it does have an incorporated temperature sensor that clicks into place and seals with an O-ring. Below is a closer look at this sensor.

Stock E46 lower radiator hose with temperature sensor
Stock E46 lower radiator hose with temperature sensor

And here's a closeup showing the quick-connect portion of the E46 lower radiator hose.

Stock E46 lower radiator hose quick-connect
Stock E46 lower radiator hose quick-connect

Plans and Development

We mentioned earlier our intention of improving the stock design. For this kit, that means we'll be using silicone as the hose construction material. Stock hoses use rubber, but silicone provides additional longevity and is substantially more resilient to the heat and pressure seen by an automotive cooling system. Silicone hoses will remain soft and flexible over time and will not harden or swell like rubber hoses can.

To capture appropriate dimensions of the hose portion of this product, we've removed the permanent (so they say) stock clamps.

Stock BMW E46 radiator hose
Stock BMW E46 radiator hose

We also needed to address the quick-disconnect portion of the hose. For other product lines we've designed these from aluminum to improve reliability over the plastic counterparts. The result is a completely bulletproof solution; however, it does raise the price of our kit significantly. The E46 is a budget sports vehicle, so we will stick with a plastic design for the connection points. These pieces should provide years of reliable service and are a nice replacement for aged units. Check out a couple shots of our hose ends!

Mishimoto BMW E46 radiator hose quick-connect fittings
Mishimoto BMW E46 radiator hose quick-connect fittings

Mishimoto BMW E46 radiator hose quick-connect fittings
Mishimoto BMW E46 radiator hose quick-connect fittings

These fittings emulate the stock pieces perfectly. They mate up nicely with not only all stock equipment, but also with the connection points on our new aluminum radiator and expansion tank.

Prototype Kit Installed

We worked up a set of silicone hoses that matched the design of the stock setup. We then test fitted this full assembly to verify that all components fit together flawlessly.

Mishimoto E46 radiator hoses installed
Mishimoto E46 radiator hoses installed

Mishimoto E46 radiator hoses installed
Mishimoto E46 radiator hoses installed

Here's a close-up shot of the upper hose connection point at the expansion tank!

Mishimoto E46 radiator hoses installed
Mishimoto E46 radiator hoses installed

And here's a look at the Mishimoto E46 lower radiator hose in place.

Mishimoto E46 lower radiator hose installed
Mishimoto E46 lower radiator hose installed

Definitely a sure fit for this kit! All components mated up perfectly, and they successfully operated in a leak-free manner once installed. Also, the temperature sensor in the lower hose clipped into place just as it would with the stock hoses installed.

For final product assembly, the hoses will be pre-installed on the fittings and will be properly clocked for an easy out-of-the-box installation.

For color-conscious folks, the red option for this setup will be joined by our black and blue silicone hoses.

Pre-Sale Information

To complement our upcoming Mishimoto E46 aluminum radiator pre-sale, we will also be launching a discounted introductory rate for our E46 silicone radiator hoses. Check back next week for details on the pricing for both components!

Thanks for reading!

-John

Interested in purchasing our E46 silicone radiator hose kit? Check out our product page linked below!

Mishimoto BMW E46 Non-M Silicone Radiator Hose Kit!