Does anyone know what goes in here?

[Button]

Does anyone know what goes in to this side hole on the thermostat housing? It's an L20 if that matters? I must be going crazy because I have had the car running (not driveable) about 2.5 years ago when I bought the car so I am assuming I had something in there at one point but I can't figure it out.I have looked in all the manuals but can not find any details.

It may be worth noting that it does have the temp sender in the front of the housing.

Thanks.

Chris

[510rob]

it might have been a thermally-controlled vacuum switch for some of the old emissions wizardry

[bertvorgon]

That is where the temperature gauge sender was mounted. I made a small adapter to mount my existing temp sender there, which is mechanical. That being said, mine faces the front of the car, but that bung looks the same. You can see mine just below the rad hose with the brassy fitting.

[datzenmike]

That's the position for the thermal vacuum switch for the EGR. Vacuum (and EGR) is only allowed past when engine is warmed up. The temp gauge sender is in the front of the thermostat housing beside the water by pass fitting under the rad hose like in Keith's picture.

I see you have the triple bolt thermostat cover only found on the '79/'80 L20Bs and a water cooled intake.


EGR.... there is none at idle, when the engine is cold or at full throttle, so EGR only affects part throttle driving (if at all) on a warm engine. Has no effect on performance

[Button]

Thank you for the feedback guys. As you said Mike the temp sending unit is coming out of the front of the housing. Also thanks Mike, for narrowing the year down on the motor. It came with the car so I wasn't sure and I have been dealing with other areas of the car so never look at the engine numbers to figure it out.

Should I just get a new switch to block it off or does anyone know the size and thread pitch to get a plug?