Thermostat Heater Bypass Hose, BMW - E30 318i/325e/325i/M3

This part is listed by BMW as BMW part number 64218367834 (64 21 8 367 834) and is described as the drain/bypass hose that runs from the heater thermostat to a T-connector in the main heater return hose. This may be found on all E30 318i, 318is, 325e, 325es, 325i, 325is, 325iX, and M3 if BMW or the dealer installed the heater core thermostat on your car. This hose bypasses the heater core if the thermostat is closed and dumps hot coolant back into the main heater return hose along the frame rail. BMW added the T-connector to this return hose to take this bypass hose.

This is a Genuine BMW E30 heater hose with a two year warranty. Buying a Genuine part will usually be more expensive than an OEM or aftermarket brand but you are assured that it meets BMW's designs for fitment, performance, and longevity. It will also be the very latest design, incorporating any updates or revisions that an aftermarket brand typically will ignore. 

For full BMW fitment information or for assistance from one of our BMW experts, we recommend calling us at 877-639-9648.