Thermostat OEM BMW or OEM Volkswagen

03’ E46 318ci with 130k miles and no issues with the whole cooling system. Neither the thermostat.

I was instructed by a friend who had some of m47 and m57, to buy thermostat only original from bmw, because everything else doesn't work as long or good.

I've got a 13 sport with 135k miles on it. Only ever done oil changes, spark plugs, 12v battery and a thermostat. Other than that it’s been stupid reliable.

The replacement thermostat came from BMW. No problems this time.

Noticed coolant was low and could smell it sometimes. Dealership pressure tested system and found coolant leak at thermostat housing. Thermostat replaced under warranty. Its probably been leaking slowly for a year or more.

Independent mechanic noticed leak. Dealership confirmed the thermostat was cracked and leaking. Took a week for parts to arrive. Took a day to repair. All covered under warranty.

Bypass thermostat yellow arrow Included with radiator upper hose and you should be able to find the bypass by itself.

I'll throw a lower temp thermostat see if I can get her temp to stay low as possible for now

Changed to genuine thermostat, no change. Needle tends to dip on higher load highway driving, but only occasionally. Obd temp is between 77C-88C.

mine is also a problem an my car is 1.5 yrs old. Sometimes the temp gauge acts as if it is -40C outside even if it is a couple degrees above freezing. Often the car will take 4-5minutes to get near base idle when it is cool outside, but when it's really cold, sometimes it takes 30seconds and there is no way it's warmed up. Can also smell coolant anytime I open the hood. Sad.