1995 3000GT: Defi Coolant Temperature Sensor Installation

• Why Do I Want To Do This?

  • The stock coolant (water) temperature gauge is designed to tell you only a few things:
    • Engine Below Normal Operating Temperature (below 3 o'clock)
    • Engine In Normal Operating Range (3 o'clock +/- a tick or two)
    • Engine Temperature Getting Too High (above 3 o'clock)
    • Turn the Dang Engine OFF! (pegged gauge)
  • As observed in my car, the coolant temperature can vary from 75C to 100C and the stock gauge just sits there at 3 o'clock. That's a large range of temperatures for no needle movement.
  • Especially if you attend track events, you probably want to keep a closer eye on your coolant temperature as an indicator of engine health and the efficiency of your cooling system.




• How Long Will It Take Me To Do This?

  • Plan for an hour so you're not rushed.




• Anything I Should Do Prior To Attempting This Procedure?

  • Drain the coolant from your radiator, at least enough so that the upper radiator hose is empty.




• What Mitsubishi Parts Will I Need?

  • None.




• What Other Parts Will I Need?

  • (1) Defi Coolant Temperature Sensor
  • 3/8" NPT to 1/8" NPT Bushing
  • Teflon Tape




• Where Can I Get the Stuff To Do This?

  	Part	Company/Contact	Part Number
  	Defi Coolant Temperature Sensor	MVP Motorsports	Defi LinkII or BF Series Coolant Temp Gauge
  	3/8" NPT to 1/8" NPT Bushing	McMaster-Carr or any Hardware or Auto Parts Store	4429K471
  	Teflon Tape	Home Depot or any Hardware or Auto Parts Store	N/A





• What Tools May/Will I Need?

  • 8mm Allen (Hex) Wrench or Socket Adapter
  • 10mm Wrench or Socket w/ Ratchet
  • 11/16" Wrench
  • 17mm Wrench

The Procedure

	Remove Intake Pipe and Spark Plug Wires
	After draining all the coolant out of the radiator, remove the y-pipe (turbo cars) or intake pipe (NA cars) and the rear spark plug wires to make some room.
	Remove OEM Thermostat Housing Plug
	Insert you handy 8mm allen wrench into the plug in the thermostat housing. If you've never removed it, it'll probably be really hard to break loose - there's some kind of Lock-tite on there from the factory. I used a 18" cheater bar and most of my body weight. Once you remove this plug, you will loose some coolant. Be prepared to catch it in a container or with towels. Another option is to have the sensor ready to thread in immediately so that the coolant loss is minimized. Thanks to Sergey Polstyanko for confirming the size (8mm) of the wrench necessary to remove this plug!
	Gather Sensor Installation Parts
	Defi sensor and brass 3/8"NPT to 1/8"NPT bushing found at local hardware store. Schucks Auto Parts also carries them.
	Install Bushing
	Install the bushing on sensor with teflon tape for a secure conenction. An extra bushing is shown for illustration.
	Put Teflon Tape on Threads
	Put teflon tape on the threads of the bushing.
	Install Sensor
	Thread the bushing and sensor into the hole in the thermostat housing. It's that simple :-)
	Reinstall Spark Plug Wires and Intake Pipe
	Put it back the way you found it and you're done! Remember to fill up your coolant!