So I received my second MTC heater control valve.

I removed the first one and what I saw was that the plunger was not centered properly in the tube, thus the reason for the hot coolant continuing to flow through the heater core.

Upon inspection of the part I was able to play around with it and get it to align back up and had it operating properly once again. However, when I started pushing at the components that hold the valve in place, in particular the pivot point, I was once again able to make the valve fail. Ugh!

With this knowledge now in had, I attempted to install the new valve back in the car in the closed position, and being careful not to touch anything around the pivot point. Even though I was careful, I did however slightly brush against it, but thought it wasn't bad, so I filled the car up and tried it out. It too failed and was letting coolant flow through the valve.

Last night I pulled the new valve out and as suspected, the valve was once again off center, and thus allowed hot coolant to flow through the heater core. Both valves are going back and I'm now purchasing a new valve that I've used before and it works very well. Not OEM, but it does work. I should have done it in the first place, but I thought I would try something that was supposed to work like the OEM one. Never again!

Matt
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1989 - 245, 1990 - 245, 1991 - 245, and 1993 - 245