Thermostat housing Question.

**viking3099** · 07-12-2003, 04:27 PM

I was wondering if anyone knew what the little vacuum sensor does that is screwed into the back of the thermostat housing does, and has lines 3 and 12 running into it. I'm curious to see if a malfunction with this would cause problems with idling.

**Immeraufdemhund** · 07-13-2003, 04:36 PM

umm. I broke mine and it doesn't have any problems with idle. Does your check engine light come on? How long has it been since a new tune up? Normally that doesn't mess with your idle.

**AccordEpicenter** · 07-13-2003, 06:41 PM

i think its a vacuum thermoswitch but i cant remember what it does... its like some kinda wax valve

**McNick** · 07-14-2003, 01:03 AM

This is thermovalve of evaporation system. This valve open, when engine temp is above ~55 Celsium and allow manifold vacuum (line #12) open purge control valve ( by #3 line).

**viking3099** · 07-14-2003, 09:38 AM

Would a malfunction with this valve cause problems with idling. i.e. : Rolling idle, High idle...

**cruznz** · 07-14-2003, 11:57 PM

by-pass the thermo-valve and connect the 2 hoses together to see if theres a difference

**McNick** · 07-15-2003, 01:08 AM

... or block both hoses to see if theres a difference.

**BITESIZE** · 07-15-2003, 01:13 AM

It might cause high idling. I believe if you take off the egr valve hose the idling will go higher, so it could make a difference. You'd have to use a vacuum tester and see how much psi is going through the lines. good luck.