Zeke21

1992 SC400

Can anyone tell me what the part circled in red is? This is located towards the firewall on the passenger side of the car, just to the side of the plastic air intake pipe.


I noticed today that I'm leaking some coolant from a hose going to it. Also in the second pic, there is a hissing/air sound coming from the red circled portion of the photo. Both photos are of the same part just a top and side view.


I didn't notice the hissing sound before so not sure if it is normal. If not, I wonder if I have a bad part, whatever it is, or if it is acting up due to the leaking hose connected to it. If i cover the 4 holes (circled in red) the noise is muffled.

Thanks for the help!

TweakTech

iTrader: (2)

It's a water vacuum switching valve related to the HVAC system

Zeke21

After doing some research the part I'm looking at is the heater control valve. After drving a day ago I notice I was leaking some coolant from where the hose connects to the valve. I wipe the excess coolant and tried to push the hose up some and clamped it down again. It seem to stop if from leaking although I do notice a drop or two around the hose but nothing like it had been leaking.

What I'm pretty concerned about is the hissing noise I'm hearing. It turns out this is coming from the solenoid. Does this mean it is bad or should the whole thing be replaced, the control valve unit? I'm not having any problems with heat or AC at this time but I know the hissing noise is new.