Exactly the same as the part from the dealership at a fraction of the cost.

I’ve heard much squawking about any expansion tank but a BMW, but this one is working perfectly for that past year and 15K miles. And the FL heat isn’t exactly kind to cooling systems. It works.

Perfect Fit

Fits and works great no complaints

They don’t seem to make these as durable as they used to. Expect a avg 1.5-3 yr life span as opposed to 3-5 yrs like years gone before.

Great replacement from my old worn out tank. Don’t forget to buy O rings for all you’re quick connectors when replacing cooling system components

Fits perfectly. Replaced the lower and upper radiator hoses, thermostat, water pump and pulley (aluminum upgrade), aux fan sensor, along with the belts, pulleys and tensioner. The upper radiator hose was a little hard to install, but a thin coat of dishwashing liquid on the hose inside o-ring did the job. Make sure to do a thorough system bleed, put enough BMW coolant, and you.re good to go. Took the car on a 3,400 mile trip (Florida-Colorado-Florida) after the cooling system maintenance and the car ran flawlessly...no leaks whatsoever.

As you might now, one of the achiles heel of the E46 Cooling System is it expansion tank, with this new part you get many more milles of trouble free driving.

The first time I installed this, I ended up experiencing a small leak at the bottom of the expansion tank. I removed it a week later and tried to reseat the o rings and whatever I did fixed it. Haven't had any problems since but from what I've heard, I wouldn't have experienced this issue in the first place if I went with Genuine BMW. Either way, for the price this was worth it.

Was surprised to see this did not come with the cap. I thought in the past expansion tanks typically included a new one. Maybe I’m wrong. However, for the price the fitment was good and it seems to be a good quality.