EGT Gauge; worth fitting, or not?

After owning our 80 Series Land Cruiser for about 6 months, I started looking at ways we could improve reliability and longevity. With a big trip coming up, a reasonably fresh engine and a need for prevention, I decided to fit an EGT gauge, to get a better idea of how the engine was operating at any given time.

What is an EGT gauge?

An EGT gauge displays the Exhaust Gas Temperature, which goes up and down considerably depending on how fast you are going, how far the pedal is pushed down and the load on the vehicle.

This is related to the amount of fuel being burnt, and the load on the vehicle, with the harder it is being worked, the higher the temperature.

Exhaust Gas Temperature Gauge
My scintex digital EGT Gauge at room temperature

Why install an EGT gauge?

EGT Gauges are most often installed on turbo charged engines, and are used to prevent failure and help with tuning engines. In most vehicles, it takes a lot of effort to get the standard engine temperature gauge to move up from its ‘normal operating’ position. In many cases, the engine has to go up 30 degrees before you can even see it on the gauge, providing you notice it at all.

An EGT gauge moves up and down very quickly, depending on how hard the engine is working. This means that you have an accurate reading of the temperature that your engine is running at, at any given time. These often come with visual and audible alarms to let you know when a certain temperature is reached (which is usually a danger point). If you go beyond that point, you are risking damage to your engine.

It is possible to have hugely high EGT readings, resulting in damage to the head, valves or pistons without the factory engine temperature gauge even moving. For engines with their temperature probe located inside the cooling system, it is possible to lose all of the coolant, cook the engine and the temperature not even move. The second your engine loses cooling ability with an EGT Gauge, you know about it!

Using your OBD2 port

If you have a more modern vehicle, you’ll have an OBD2 port under the steering wheel, which will allow you to access a heap of information from the 4WD’s ECU. On our new 2016 Dmax, we run an ultragauge, which tells you everything from coolant temperature to battery voltage, fuel rail pressure and everything in between.

Ironically, it does not measure EGT’s as it has no probe, but if it did (like the 2017+ models) you would be able to read it without any additional gauges.

Ultra Gauge mounted on our windscreen
Our Ultragauge which reads everything the vehicles computer has access to

How does an EGT Gauge work?

EGT Gauges have a K type thermocouple which is stuck inside the exhaust pipe. The thermocouple sends a temperature signal to the gauge, which then displays it.

EGT Probe; k type thermocouple
EGT probe into the exhaust

Tuning and EGT Gauges

In many cases, people that install EGT Gauges do so because their engine has had work done to it. If you are playing with fuel/air ratio, fitting a larger turbo or running higher boost, a quality EGT Gauge is a must. Without it, you may find that the engine runs too hot and does damage.

Before or after the turbo?

In most cases, the EGT probe is recommended to be installed before the turbo, as close to the cylinder head as possible. However, this is not always the easiest installation, and a number of people go behind the turbo.

Beaudesert Exhausts have holes already drilled and tapped, to allow for the EGT probe to fit after the turbo. Providing you know what temperature the probe should run at the position you install it, you won’t have any issues.

What temperatures should the gauge run?

For the 1HDT (4.2 turbo diesel 80 Series Land Cruiser engine), anything above 500 – 550 after the turbo is dangerous. The temperatures before the turbo are obviously going to be hotter; don’t forget to take this into consideration. Different engines are designed to run at different temperatures, so make sure you look into it!

At 100km/h, my Land Cruiser sits in between 270 and 280 degrees. At 110km/h it sits in between 320 and 330 degrees celcius. This is kept relatively cool due to a good tune and the safari intercooler. Most gauges have the ability to display Fahrenheit too, if you prefer it!

Digital vs Analog EGT Gauges

I couldn’t stand having an analog EGT Gauge. They take longer to read, and for exact measurements are not ideal. However, a lot of people run them and even prefer them. For me, being able to glance at the gauge and know I have the exact reading is important; I want to watch where I am driving, not spend all day reading a gauge!

The digital gauges move around constantly. They never sit still. You can put your foot down half a millimeter and guarantee that the temperature goes up, even just a few degrees or so.

Where can you mount an EGT Gauge?

There are a few places that people mount EGT Gauges. Where you do it comes down to personal opinions, but make sure that it is easily readable, legal and that it looks half decent. Some of the more common locations include:

  • On top of the plastic behind the steering wheel
  • In the dashboard (in one of the spare switch locations)
  • At the bottom of the dashboard (around the gearstick)
  • On top of the dashboard
  • Inside one of the A pillar mounts
  • On the front of the center console
  • In an overhead console
Mounting an EGT requires a bit of thought
Under the dashboard

Installing an EGT Gauge

Installing an EGT Gauge is very simple. Firstly, look over the exhaust to see if any holes have already been drilled and tapped. The more well known exhausts come with holes already set up for EGT probes.

If you don’t have one, you need to get one installed. This can be as simple as drilling a hole and running a tap through it, or as complicated as removing the exhaust and welding a socket in place.

EGT Wiring
Wiring up the sensor cable

Once you have the EGT gauge, attach the probe (which usually has an olive to squash onto the probe) and run the wires through the firewall and into the vehicles cab. Power can come from existing accessories (like the cigarette lighter), and then you just hook the wiring up to the gauge.

I must make a note though; my Scintex EGT Gauge would not work off the cigarette lighter plug; the voltage wasn’t enough. Even at 11.5V, it just wouldn’t work. We had to run new wiring from the battery, and tee into the cigarette lighter plug via a relay to ensure maximum voltage. As my electrical skills are nothing fancy, I installed the mount, ran the sensor wiring and asked a mate to do the rest!

Setting up a buzzer

Some EGT Gauges come with buzzers already included, and some don’t. In my opinion, these are a great idea. This eliminates the need to be constantly looking at the gauge; if the temperature hits a preset temperature then you have a buzzer to notify you anyway.

Where can you get an EGT Gauge, and how much are they?

EGT kits (probe + wiring + gauge) cost in between $100 and $300 (obviously there are more expensive ones though!). I recommend getting them online; it is ridiculously cheaper, and they are delivered to your door! Some of the better known brands include: SAAS, Auber, Auto meter, VDO, Cobalt, Scintex, Drift and Defi.

EGT Gauges are well worth their money; even just as cheap insurance. I am very happy with mine, and the extra peace of mind goes a long way! I will never look at my factory engine temperature gauge the same way!

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  1. Hey Alberto,

    The temperatures limits vary based on where you have the gauge mounted. Pre turbo will always be higher than post turbo.

    You are correct about the intercooler.

    I suspect more fuel = more heat, unless you have the air flow to go with it (boost).

    All the best

  2. Hi there.
    Very nice info about the EGT gauge.
    I have 24 v 1996, I changed the turbo and with 3000 rpm ( 138 km/h ) cruise control,
    the EGT is 710 F, and climing a little on a hill on motor way it s up to 830……850 F. I think it s to high .
    I believe also that the intercooler does not put the EGT down.
    Is correct, will get more air in de cilinders and hotter burning
    I thing it s possible to run the engine more rich to lower the EGT
    Alberto ( Spain )

  3. Hey Rick,

    I made that aluminium bracket, and attached the gauge to it. That’s the bolt you are referring to. The bracket screwed into the dash.

    All the best

  4. Rick Archer says:

    Hi ,
    You seem to have bolts sticking out the side to mount on a bracket . Did you have to drill enclosure to mount Egt display surface ?

  5. “…this is kept relatively cool due to the Safari intercooler.”

    I doubt that your Safari intercooler is the reason for your cooler exhaust temperature because in its dropping the temperature of the compressed air (heated air) exiting the turbo, an intercooler increases the amount of oxygen entering the cylinders for a hotter burn when more fuel is injected to effectively use the extra oxygen.

    Cheers, Jonty

  6. It wouldn’t hurt to install one, but its probably not as important as if you had an aftermarket turbo