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Gary, Technician
Category: Car
Satisfied Customers: 17023
Experience:  GM master tech for 15 years/ASE master tech for 20 years
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1990 isuzu: changing..a bolt that screws into the housing..sits

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I have a 1990 isuzu with the 2.3 engine and I was changing the thermostat and there is a bolt that screws into the housing the thermostat sits in and it has a port coming from it that has 2 lines coming from it. I broke it off the bolt and was wandering what it is for. Is is a ported vaccuum for something?
is that vaccum switch in area of the thermal vacuum valve in this picture? that should have 2 vacuum ports off itgraphic
Customer: replied 5 years ago.

That doesn't look anything like what I'm talking about. The thermostat sits inside and the bolt screws into the housing the the thermostat sits in


those 2 ports on that bolt where connected to vacuum lines correct?
Customer: replied 5 years ago.

yes that is correct


ok that is an emiisons control that uses the coolant tempature to either open that vacuum port or close it to operate vacuum to an emissions devise.or course it needs to be changed.but you are able to plug off those vacuum lines and be able to drive it to the parts store to order a new one.
Customer: replied 5 years ago.

ok well will it make the truck run hot? I changed the thermostat and it was running hot, but I took the thermostat out and it is fine. I tried to replace this part, but they didn't know the name of it at the parts store. The catalytic converter has been taken off so do I even need thes lines anyway?


no that thermal switch will NOT effect the engines coolant tempature at all.
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