Installation of inline thermostat on my 2003 DII
1. Remove the lower radiator hose
2. Remove the center hose shown below and the coolant expansion tank hose on the right.
Lower Radiator hose for 2002 BMW 330
http://www.rockauto.com $12.98
3. Cut the end caps off by cutting as close as possible to them
4. Install and make sure the hose fits square on both ends and that both clamps are positioned correctly
5. Reinstall the coolant expansion tank hose
6. Then install the coolant expansion tank hose over the new BMW hose
7. Buy this adapter and use a 1/8th NPT water sensor or petcock to bleed the system

1/8 NPT Petcock
8. Buy this thermostat housing
MEZIERE Enterprises or Summit Racing

Inline thermostsat housing, 1 1/4" hose inlet side, 1 1/4" hose oulet side
10. Buy 180 degree thermostat
11. Drill 1/8th hole
12. Use the highlighted hose and cut off to fit accordingly to fit between the water adapter and thermostat housing. This is the hose that was removed earlier from step 2.
13. Cut the fan shroud to fit the housing
14. The coolant should flow downward
15. Bleed coolant system