BMW 3-Series E36 Expansion Tank 1992-1999

Interested in picking up this aluminum E36 expansion tank? Check out our product page linked below!

BMW E36 Aluminum Coolant Expansion Tank!

The time has come and the anticipation is over. Our final prototype unit has been constructed, and we are ready to check fitment! On to the pictures!

Final Expansion Tank Images

Mishimoto expansion tank prototype

Mishimoto expansion tank prototype

Mishimoto expansion tank prototype

Check out a closer look at the lower coolant hose fitting and our threaded fluid level sensor bung on the base of the tank.

Mishimoto expansion tank prototype fittings

We also stamped our Mishimoto "M" logo into the side of the tank. Although not super visible once installed, this is a nice subtle inclusion to identify this tank as another awesome Mishimoto component.

Mishimoto expansion tank logo

Now the cool part! Check out the fill neck and dipstick we have designed for this tank.

Mishimoto expansion tank top

This part of the tank deserves some extra conversation. The

Interested in picking up this aluminum E36 expansion tank? Check out our product page linked below!

BMW E36 Aluminum Coolant Expansion Tank!

Time to break open the stock tank and see what lies within. If you follow some of our other development projects, you would know that we recently split an E46 3-series expansion tank and found quite a complex system including both internal and external features. Although this added some complexity and difficulty to the project, it seemed like our engineers enjoyed the challenge.

Stock Expansion Tank Internals

First, before we slice this guy in half, a look inside the tank from the cap.

Stock expansion tank, internal design

We can see from this shot that the tank does indeed feature a unique internal chamber. A tube appears to run the full length of the tank. Let's get to the band saw so we can split this component for evaluation.

Stock expansion tank, internal design

Stock expansion tank, internal design

Stock expansion tank, internal design

The internal

Interested in picking up this aluminum E36 expansion tank? Check out our product page linked below!

BMW E36 Aluminum Coolant Expansion Tank!

Historically, BMW vehicles have been plagued with rather frequent cooling system failures. A majority of these failures are a result of the use of plastic components in a high-temperature application. Although failure isn't immediate, over time the frequent heat cycling of these plastic components results in increased fragility, fatigue, and eventual failure.

A few components we see failing on E36 models include the radiator end tanks, radiator expansion tank, and the mechanical fan. We already offer two aluminum radiator options, and we have an electric-fan conversion kit in the works. An expansion tank is our last stop for product development on the E36 (for now). We have had numerous requests for this component on both the 36 and 46 chassis, because folks are not pleased about having to replace this unit over and over again. They would prefer an