M20B25 T-Stat Housing Question

[Jon325i]

I recently purchased a t-stat housing (from IPS-Parts) as part of a refresh I'm doing. When I took the item out of the packaging, I noticed there are 2 additional threaded holes on this housing that my original doesn't. Not sure why this is....has anyone see these before and can you explain their purpose? I snapped a couple of photos to illustrate my inquiry.





The question I have is can I put in a couple of thread-matched bolts to plug these or should I return it and get a correct housing that matches the old part currently on the motor?

Thanks for your help.

Jon

[jlevie]

In the past there were two different thermostat housings. One with four ports for M20B27 (ETA) engines and one with two ports for M20B25 engines. A while back BMW dropped the two port variety and all new housing have the four ports. When used on an M20B25 engine you plug the extra ports. I don't know what the part number is off hand, but you can get the plugs and seal rings from rmeuropean.com on the same page as the housing.

[Jon325i]

^^^ Good info - Thanks!

[SpecM]

if you dont mind, look at the outlet on the bottem side... the one that connects to the throttle body heater. is it 3/8 or 1/2 in?

i repalced my t-stat housing and it had a 1/2 nipple. OE is 3/8....

[Jon325i]

if you dont mind, look at the outlet on the bottem side... the one that connects to the throttle body heater. is it 3/8 or 1/2 in?

i repalced my t-stat housing and it had a 1/2 nipple. OE is 3/8....

Just checked the used core....3/8". New one is 1/2".

[SpecM]

Just checked the used core....3/8". New one is 1/2".

right

good luck trying to get that 3/8 hose over that 1/2 nipple!

I got a 1/2-3/8 plastic hose barb and some 1/2in heater hose from NAPA that I had to make work

I would like to replaced the threaded fitting at the back of the block with a 1/2 one so I can use a plain 1/2 hose front to back