Safety Series – Redarc Gauge System

There is a little secret that I haven’t really let many people in on. It’s funny how a car guy’s brain works – they never want to publicise any type of vehicular failure for fear of being judged! Today, I’m letting one out of the bag.

So 3 years ago on the way home from the Big Red Bash the little turbocharger on the ZD cried enough and packed it in about 300kms from home. We were heavily loaded as we were carrying a lot of gear for the event, but also supplies as we were travelling in a convoy on an 11 day trip. Loaded as we were, the weighbridge down the road from the office said we were within bounds. The tell tales were increased soot from the tailpipe, dropping performance and warning lights on the dash. Pulling up and adding some fuel conditioner (I thought it was a bad batch of fuel) as well as checking all the intake-side hoses, pipework and intercooler for leaks (I had replaced the air filter before I left Birdsville as it was caked), funnily enough gave me about 100kms of relief.

Then it came back and worse than ever. Backing off the Steinbauer to minimise over-fuelling and taking it very easy in the left lane, I was still giving my brother-in-law Shane who was trailing me a nostril full of soot all the way to my mechanic in the Blue Mountains. Whilst I was monitoring the vitals on the various gauges available on the dash, in the absence of a scan-gauge I was relying on the warning systems built into the factory Nissan ECU – not ideal.

Upon tearing down the intake side of the old grenade, the verdict was a warped intake manifold (a common issue for these motors) and an intake side turbo shaft that had too much play. The icing was a motor that had oily dust right through it.

A new factory spec huffer and a machined manifold with a couple of new studs, along with a good EGR clean and the old four pot was back up and purring. It was at this point that we decided to attend to the issues inherent in the ZD30 – power, or lack thereof. We bolted on a Cross Country Intercoolers ultimate intercooler to keep the intake temps down, as well as their catch can kit to minimise oil mist running through the engine and making a mess. On the exhaust side we decided on a Redback 3inch Heavy Duty exhaust system from the turbo back. These two mods helped the asthmatic ZD breathe a little easier and improved driveability markedly.

Most importantly, the Redback Dump Pipe had a bung to mount a pyrometer probe – critically, something we didn’t have before. The key is to measure Exhaust Gas Temperature (EGT). Now I’m not a mechanic and there are plenty of smarter, more technical people out there that have unpacked this subject, but basically it is a turbo diesel engine’s kryptonite. A turbocharger is driven by exhaust gas, now if that exhaust gas is too hot for the various metals used in this complex intake system, then there is potential for warping and other damage that leads to failures such as the ones diagnosed in our case.

The ZD30 is known to run hotter EGT’s than most engines – but they also are known for falling on their own sword. Having on-demand access to EGT’s and Boost pressure using the Redarc gauge system we put in as part of this repair has been an integral safety addition to MobileHQGU. Having these gauges on hand may have helped diagnose or manage the situation better – or at least have another line of information to help ascertain that things were going wrong.

Running pride of place on the A Pillar along with the voltage gauges for MobileHQGU’s dual battery system – the gauges are linked and use an enhanced lighting controller to allow for dimming control. Perhaps the most impressive feature of these gauge systems is the ability to set customer alarm points. Adjustable to the complete range of the readout, once limits you set are triggered, a combination of an audible buzzer along with a change in the colour on the backlit LCD screen will alert the driver. Our MobileHQGU is often driven by various members of the team, as such setting alarms for EGT, battery charge and boost has been a good way to ensure any chance of damage or issues are minimised.

The last 75,000 kilometers of driving has been completely uneventful, with the odometer now reading just north of 150,000 and I have no reason to believe that the ZD would not keep spinning for another 100,000 with no issues. Anyone who is doing any sort of serious remote touring needs to have access to quality information about the performance of their engine – the old saying prevention is the best cure rings true – cheap insurance if you ask me.

Happy Touring


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Comments 13

  1. What temp have you set your EGT alarm for and what do you consider the max temp you will accept before backing right off?

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      Hi Iain

      I’ve got the alarm to come on at 550, which is very conservative for this engine. They do run a little hotter than most, but i’d rather err on the side of caution. Generally i just back off, or flick off the overdrive once i’m above that number and things come back into control. But sometimes when overtaking or in sustained inclines you really can’t help it – i release the right foot when i see 700, but again, that might only happen once every 3 months



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  2. Howdy. A very interesting read.
    You did however leave a bit out.
    An EGT gauge will also allow you to find your vehicles sweet spot – that point where speed, power are up with temp and consumption down.
    I would consider this a must for any mid size 4×4 towing a van or other heavy load. I have one fitted to my 2010 triton and its amazing what you can learn about your vehicle just by watching the gauges.
    Happy travels.

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  3. Could not agree more fully! Based on years of driving trucks, I have always installed additional gauges in my vehicles so I know what is going on, and more importantly, what might be about to go wrong before it does.
    Temperature and oil pressure gauges helped to save a S3 Land Rover from seizing from coolant loss, detect a blocked radiator in a GQ Patrol and allowed us to keep moving on days of over 40 degrees towing a caravan Against the Wind in the West.
    I prefer direct reading gauges, but the electronics and design of more today’s vehicles makes this impractical as I found out with my GU Patrol. I did fit a ScanGauge to it in fear of the reputation of the engine to self combust, but it was early days and there wasn’t the number of readings I wanted available for the Patrol.
    When a 200 Series Land Cruiser replaced it, I moved the ScanGauge over and all seemed well. However, the ECUs started to throw up all sort of errors and wild readings, so I had two multifunction REDARC electronic gauges fitted with the light controller instead. (Turns out that the connector cable had been damaged and repaired by someone working on the vehicle, which you can not do according to the distributor Ample Outdoors, and this was the cause of the problems. The things you learn after the fact.)
    It was a costly exercise fitting these gauges, and quite a challenge as modern vehicles are not designed for extra bits like this to be added to the dash area. I wanted to mount them on the A pillar like yours but was concerned about interfering with the operation of the air bags and the the legalities of restricting forward visibility for the driver once a rear view camera monitor and phone cradle were in place.
    So a place was made in the console, but the face of the gauges can become difficult to read in direct sunlight, especially as the ‘needles’ are quite thin. (I can send a pic of the installation spot if you like). I am experimenting with hoods over the gauges to shade them at present and have been talked to REDARC about the need to be able to adjust the contrast of the dials etc. At night time they are brilliant.
    Even so, as we tow a big van, the gauges have paid for themselves time over as even the Land Cruiser feels the weight and I can adjust speed and gears accordingly.
    What intrigues me are the people, often with heavily laden vehicles, who just ‘push on’ without considering or knowing what their engine or transmission are up to. With the extraordinary costs today of repairing or replacing a engine or trans, it seems to me to be like playing ‘Russian Roulette’ with all chambers loaded!

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      G’day Mark,

      A great snapshot of how such a simple thing as a gauge can make a world of difference – thanks for sharing.

      With the alarm and colour changing process of Redarc’s gauges though, being able to read the numbers isn’t as important??


  4. Agree totally I have just fitted the Redarc 3 way gauge and it is amazing just how much is revealed about what the engine is doing particularly when towing a 3ton van around the top end. Has been money well spent and combined with a Scan Gauge has helped give engine saving information. My only advice is make sure that the EGT probe is fitted onto the manifold not further down the exhaust system for more accurate temperature readings. Thanks for the great overview. Gary

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      Hey Gary,

      There are many different views on where to put the probe – ours is on the dump pipe – which some people say is not as accurate and i know the reasons why.

      For me, our Redback Exhaust System came with the pre-welded bung so we just went with that. I think as long as you are conscious and are monitoring things either way is better than nothing.


  5. Fitted EGT guage to our 2004 Patrol 3L some years back and it completely changed the way I drive. Vehicle has now done over 334000klm of trouble free touring and runs like a dream. Should be the first accessory fitted to any diesel especially if towing

  6. I have been using the Redarc gauges for several years. They may not be cheap but believe me when I say they are well worth the investment and an investment is exactly what they are.
    I have the dual EGT/boost and water temp/oil pressure as these to me are some of the most important things to watch, if these go wrong in the middle of nowhere you need to know about it immediately to avoid catastrophic engine failure.
    The other thing about Redarc is the back up support. I had a gauge fail outside of warranty and it was replaced without fuss, you don’t get that support from the cheapies.

    Highly Recommended!

  7. I have a Redarc dual volt/amp gauge fitted to the pillar of my 4WD and as nice as it is I find it very hard to see those pale grey digital pointers during daylight hours. I can read the Amp numbers just fine however. I have tried all the colour combos but no joy, the pointers are and always have been a bit too faint to make out with a quick look. Because of this I feel my gauge is actually a driving hazard if I try to use it while on the move and am considering either fitting a hood to it or replacing it with something less digital.
    I must admit I am somewhat surprised that such an expensive gauge from such a reputable company has this kind of weakness.

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