I replaced 100% of my cooling system in my 2004 330ci Convertible before driving it 4000 miles from Alaska to TN. After the rebuild, took it for a 600+ mile test drive, from Delta Junction to Anchorage and back. Had, and continue to have, ZERO leaks or other issues over 20K miles later.

I got this thermostat back in August, and it is September and I spotted the thermostat leaking really weirdly. I've noticed I have vacuum in my cooling system bc after I open my hood I see the upper coolant hose deflated. Yes my cooling system is bled. I believe the thermostat could have also failed due to the plastic coolant leaking. Lets see if it lasts longer after warranty swap.

Replaced thermostat 6 months ago. Still runs well and had no issues.

perfect fit , good price and took cafe of engine light

This part cleared my engine "map cooling" code, fit perfectly, and has been great ever since, car warms up much faster aswell. Remember to take a razor blade and gently scrape the block to clean any corrosion so you get a good seal. And go in a circular pattern tightening evenly around the housing so you do not crack it.

Perfect fit, little over 1k miles no more overheating no more leaking.

Perfect fit, little over 1k miles no more overheating no more leaking.

Good quality replacement. Been installed for over a year now with zero problems.

Mine leaked after about a year

Mine leaked after about a year