1.6 thermostat replacement...housing won't seat

[hoehn000]

Thermostat was intermittently getting stuck closed, so I decided to replace it on my 1.6 na diesel in my 85 Passat.  Purchased new from german auto parts with o ring.  This is something I've done many times on many old VWs.  Drained coolant, bolts came out no problem and with housing off I was easily able to remove old (original) thermostat and o ring.  New ring in and new thermostat in no problem....BUT...now the housing will not seat in the water pump.  No matter what I do the housing will not seat.  If I remove thermostat it seats perfectly fine.  If I put old thermostat in it will not seat...not even close.  Any ideas?? Very very weird and equally frustrating.  Thanks 

[RunninWild]

What order did you put them in? Supposed to be thermostat then ring on top.

[hoehn000]

Thermo goes into water pump first followed by ring then housing bolts up...trouble is housing is not seating.

[RabbitJockey]

are you just being confused because the new oring must be squished and the old o ring was already smashed and deformed?

[hoehn000]

That was my first assumption, but it's not seating with the new ring/thermo or old ring/thermo or any combination of the 2.  The housing is sitting crooked on the water pump.  I understand this all sounds crazy that it's not going together, but I'm at my wits end.  I've done this a dozen times and never had a problem...after a couple hours of trying I was laughing to myself figuring I finally deserve to be committed to the mental ward.

[sgnimj96]

  Not sure what to tell you
https://www.youtube.com/watch?v=KMjO727wZ9w
They sell new thermostat housings,  make of plastic now to be cheap

[ORCoaster]

Does the new thermostat have a funny indent in one particular place that must be aligned with the housing?  I noticed that on a recent redo of my Ford Ranger.  It seems to be connected with the little tab that allows water to flow if the thermostat sticks closed.  I don't know how to adequately describe it but if you look at the stat you see it is not the same all the way around.  And the housing needs it to be aligned just so to allow it to drop down into place.