Engine block or head temp?

Hey team, I've ordered one of these Engine Guard temperature gauges. I needed something with a small digital display and this seemed to be the only thing I could find that fit the criteria.
The one I have ordered comes with a 1/8NPT liquid temperature sensor which I will screw into the top thermostat housing, and a second bolt on sensor.
Where would be the best place to mount the bolt on surface temperature sensor? Thinking either the block or the head but even then in what position on either?
I wouldn't have bothered with the second sensor but the extra cost was negligible and may help to identify an engine getting hot from losing coolant where the liquid sensor would not.

https://engineguard.com.au/product/e...kaAtBFEALw_wcB

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Originally Posted by Winnie

Hey team, I've ordered one of these Engine Guard temperature gauges. I needed something with a small digital display and this seemed to be the only thing I could find that fit the criteria.
The one I have ordered comes with a 1/8NPT liquid temperature sensor which I will screw into the top thermostat housing, and a second bolt on sensor.
Where would be the best place to mount the bolt on surface temperature sensor? Thinking either the block or the head but even then in what position on either?
I wouldn't have bothered with the second sensor but the extra cost was negligible and may help to identify an engine getting hot from losing coolant where the liquid sensor would not.

https://engineguard.com.au/product/e...kaAtBFEALw_wcB

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Not sure on the engine but maybe on the top tank of the radiator? A low water sensor is the best for alarming you if there is coolant loss. Its real handy too when your filling up the cooling system too, it will keep going off if you haven't burped the system properly.

Chris,

I run 4 of these, dual sensor units. I have found the simple bolt on units the best. I tried their liquid sensor and it was way off the mark to be honest, confirmed with both an IR gun and one of their bolt on units side by side and also a totally different unit. I made contact with the owner and he was great, however wanted a couple of 'swap this for this' and they were reasonable except for the amount of junking I had to do, so I discarded the liquid unit for a purpose made unit for the application. I use the unit for water simply as a bench mark rough temp indicator for under bonnet temps and it seems to be quite accurate for that.

I have clamp on ring connectors on the gearbox and transfer case, insulated thermally. I also have sensors clamped on the in and out of the oil cooler and the same for the radiator on the actual spigots. The minute difference between direct contact and the metal on metal contact with conductive paste is not worth thinking about in my view.

There are actually 2 revisions of these sensors and the latest ones, which i would presume you have a wider range of options than the earlier ones. I have 3 earlier units and one current unit. I am very happy with the performance and the only thing you need to pay attention to is the very thin sensor cable - its easily crushed or crimped or cut. You will know if this happens as the sensor will tell you.

For water i use the Redarc low water sensor alarm. Its a bit sensitive especially on a hill, but just another instrument. I tried the Engine guard for the intercooler water circuit as wanted to measure IN and OUT temps, but thats where it failed so went with a special unit out of the UK that looked better, and then a different set of instruments for the IN and OUT of the air temps as engine guard only offered the same water fitting for air as well.

If the connection is a good clean firm one then I don't think you can beat the ring electrical version. If you already have the unit with a screw in, i would try to validate its accuracy - i did this with a cup of boiling water and mine was 40 deg off, but I think this is an execption rather than the rule.

If you are putting it in a liquid stream, find somewhere that is bubble free, as this will be an insulation zone, and preferable at the bottom of the pipe, not the top.

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Originally Posted by PeeBee

Chris,

I run 4 of these, dual sensor units. I have found the simple bolt on units the best. I tried their liquid sensor and it was way off the mark to be honest, confirmed with both an IR gun and one of their bolt on units side by side and also a totally different unit. I made contact with the owner and he was great, however wanted a couple of 'swap this for this' and they were reasonable except for the amount of junking I had to do, so I discarded the liquid unit for a purpose made unit for the application. I use the unit for water simply as a bench mark rough temp indicator for under bonnet temps and it seems to be quite accurate for that.

I have clamp on ring connectors on the gearbox and transfer case, insulated thermally. I also have sensors clamped on the in and out of the oil cooler and the same for the radiator on the actual spigots. The minute difference between direct contact and the metal on metal contact with conductive paste is not worth thinking about in my view.

There are actually 2 revisions of these sensors and the latest ones, which i would presume you have a wider range of options than the earlier ones. I have 3 earlier units and one current unit. I am very happy with the performance and the only thing you need to pay attention to is the very thin sensor cable - its easily crushed or crimped or cut. You will know if this happens as the sensor will tell you.

For water i use the Redarc low water sensor alarm. Its a bit sensitive especially on a hill, but just another instrument. I tried the Engine guard for the intercooler water circuit as wanted to measure IN and OUT temps, but thats where it failed so went with a special unit out of the UK that looked better, and then a different set of instruments for the IN and OUT of the air temps as engine guard only offered the same water fitting for air as well.

If the connection is a good clean firm one then I don't think you can beat the ring electrical version. If you already have the unit with a screw in, i would try to validate its accuracy - i did this with a cup of boiling water and mine was 40 deg off, but I think this is an execption rather than the rule.

If you are putting it in a liquid stream, find somewhere that is bubble free, as this will be an insulation zone, and preferable at the bottom of the pipe, not the top.

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Thanks heaps for that info Phil, I'll do a test on it for sure before install.

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Any issues with the instrument, get straight onto the guy in Cairns. He is a really good guy and knows his product. I will use his gear again if required despite the hiccup with the one instrument that didn't work out.

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Originally Posted by PeeBee

Any issues with the instrument, get straight onto the guy in Cairns. He is a really good guy and knows his product. I will use his gear again if required despite the hiccup with the one instrument that didn't work out.

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Thanks again Phil. I will let you know how the product pre-install test goes.
I haven't received the unit yet, still with Australia Post.

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I received the unit today and tested both sensors in hot water comparing to 2 other accurate thermometers and both of the engine guard sensors showed the same reading as my thermometers.
Will work on the install tonight.

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Beers in the shed !!! Just got home, cracked one and time to relax and play with the 4by. . .

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Originally Posted by Rossco

Beers in the shed !!! Just got home, cracked one and time to relax and play with the 4by. . .

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Yeah keen! Was planning on doing it tomorrow but have to make an emergency run to Nicholson tomorrow.
I could even use the bolt on one to take a gearbox temp... No idea what I'm going to do with it!

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Does anybody know what size hole is required to be drilled for a 1/8NPT tap?
The 1/8NPT tap was luckily the only imperial tap in my kit but has no info on what size hole to drill.

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Originally Posted by Winnie

Does anybody know what size hole is required to be drilled for a 1/8NPT tap?
The 1/8NPT tap was luckily the only imperial tap in my kit but has no info on what size hole to drill.

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Hi mate, you should be able to size by eye. Look through the thread at the drill bit. You want to see the bit is bigger that the shaft but smaller than the thread.

I went that bolt on dual sensor unit and think I will do top and bottom of engine?

There is a really interesting thread on FB asking TD owners what their Normal hwy water temp is. I have been following along just for interest and it seems anywhere from 75 to 95 is pretty normal. I will tag you in it.

21/64 drillbit for 1/8npt. Thats 8.3mm. You'll get it with an 8.5mm

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Originally Posted by Ben-e-boy

21/64 drillbit for 1/8npt. Thats 8.3mm. You'll get it with an 8.5mm

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Cheers mate that answers my question perfectly.
Didn't get a chance to play with it tonight but I did upgrade my dual battery wiring and cable to the rear of the car. All 35mm now and very minimal voltage drop to the compressor/fridges/oven in the back now.
The 10mm I used before was capable of what it was intended for at the time but things got a bit out of control and I should be future proofed for a while now.

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If you have the coolant temp probe version I would try and use the second "bolt on" sensor for oil temp monitoring/alarm.

Thats what I had planned on mine but when I arseholed the 5 speed and put the 4L85 auto in the beasty I changed to coolant temp and auto tranny temp.

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Originally Posted by the evil twin

If you have the coolant temp probe version I would try and use the second "bolt on" sensor for oil temp monitoring/alarm.

Thats what I had planned on mine but when I arseholed the 5 speed and put the 4L85 auto in the beasty I changed to coolant temp and auto tranny temp.

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I like the idea ET. Engine Guard recommend using a SS hose clamp to attach the bolt on lug to one of the oil filters to take oil temp. Doesn't sound very accurate?
Any better ideas out there? I feel like knowing the oil temp could be very handy.

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Originally Posted by Winnie

I like the idea ET. Engine Guard recommend using a SS hose clamp to attach the bolt on lug to one of the oil filters to take oil temp. Doesn't sound very accurate?
Any better ideas out there? I feel like knowing the oil temp could be very handy.

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Chris, it will be fine, its not like you need +/- 1 deg accuracy. I have used this in exactly that location for years. Its going to very close to a full contact probe, rest assured. If you are concerned with air stripping the heat away, stick a blob of insulating rubber insulation over the top of the probe head - I have some at home, will let you know what its called and can even cut you off a couple of inches and post it to you if you like. I use this stuff on the interchiller temp sensors as well.

Thanks Phil, I'm more than happy with +/-1 deg, and I trust your professional opinion. . I honestly thought losses through different materials there would render the reading completely irrelevant.
Unless somebody comes up with a better idea for an accurate-ish reading for oil temperature, that is what I will do.

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Originally Posted by Winnie

Unless somebody comes up with a better idea for an accurate-ish reading for oil temperature, that is what I will do.

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I’m shocking, still running one of them cheapo (illegal) oil pressure gauges into the GU 6.5 cab via clear piping hose.
Thinking about adding a ‘T’ piece with stop valve before the gauge so I can in cab finger drip test whilst driving whether it burns my pinkies or not[emoji23]
Quite incredible though how oil pressure at cold idle on a 6.5 can drop from 10psi to 5psi after a tough workout, as dodgey as it sounds, and is, the old girls oil pressure gauge lets me know I’ve overdone it [emoji23]
Temp gauges are betterer for sure [emoji106][emoji106]




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Originally Posted by Winnie

Thanks Phil, I'm more than happy with +/-1 deg, and I trust your professional opinion. . I honestly thought losses through different materials there would render the reading completely irrelevant.
Unless somebody comes up with a better idea for an accurate-ish reading for oil temperature, that is what I will do.

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If you want the highest accuracy you would go direct contact between the fluid and the instrument simply as there are no heat losses at the boundary faces over and above the conduction of the heat thru the metal probe body, ie heat from motor transferred to oil, oil transfers heat to the outer casing of the direct contact probe, heat migrates thru the probe metal, likely thru a conductive paste inside the probe head to warm the thermocouple tips which has a small electrical voltage, and the resistance changes as the metal probe wires heat up, and you get your variable scale output read as DegC.. With the clamp on config, you go engine oil to filter housing body, thru the metal thickness - there are insulating temp drops depending on the thickness, then out the other side of the filter housing, where you strike an insulator, being the paint of the filter, then you bright metal clamp probe, heats up and transfers the heat to the thermocouple head which is soldered to the clamp ring, and the whole voltage/resistance thing happens as above. So there is some efficiency to be gained with direct contact, however you only get the benefit if you have calibrated and matched instruments of a high standard and your physical operating environment is stable. For automotive applications outside of test rigs, the calibration would be relatively ordinary compared to industrial and certainly miles off lab level. This is why there can be such a wide range of results with even two instruments sitting side by side - calibration variance, quality of components and the physical locations could experience het cold, water/cold air etc.
Years ago I was chasing accuracy on a steam jacketed heating kettle I had designed and it needed to hot a sauce at a preset temp for a 5 minute period to ensure all the bugs were killed. The product was super sensitive to over temp conditions due to the fat content, and would break down and seperate in a horrible blob of circa 800kg, all lost product. If not heated high enough, the kill step was not achieved so the process was delayed until it was, thus impacting production lines with no product. Anyway, I engaged an instrumentation tech to help me and we used all highly calibrated instruments with very high sensitivity, still could not get the accuracy. Turned out the paddle design had generated an un stirred pocket right over where the probe was and was reading 3 deg out. Took 2 weeks to find that. The instruments were fine, the accuracy was exceptional, but the physical location turned out to be crap due to this quirk within the kettle stirring design. I added a deflector to the stirrer arm and moved the probe 25mm away and it suddenly all worked beautifully. Once again, the best instruments can't compensate for a bad installation. In theory it should have work from the get-go, but this one product snookered me fair and square - another design lesson.

I bought a digital temperature sensor on Ali Express. I disassembled the standard sensor and inserted it inside, added thermal paste and sealed it.

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That's neat.
I have got my engine guard up and running with one probe in the lower thermostat housing and another clamped onto the oil filter.
I had to call Phil from Engine Guard to go through a couple of things and he was great to talk to over the phone.
Overall happy with the unit so far but it will get a good test this weekend towing the caravan.
http://www.nissanpatrol.com.au/forum...2020/11/68.jpg

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Any suggestions on roughly where you would expect the oil temperature to be at a steady coolant temp of 80-83C?
I clamped the sensor onto the primary oil filter and feel like it is reading low. It might be fine but I would have expected the oil temp to run hotter than the coolant. It is reading significantly lower.

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My 'hot oil temps' match the hot/off engine water temps' within 2degC. at normal running temps, so 86water = 88 oil. I have my temp sensor for HOT clamped onto the outside of the filter body.

Thanks Phil. My oil temp is reading 10-20C lower than the coolant temperature. Occasionally they will come to a parity but the oil temp will never surpass the coolant temp.

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That sounds a bit weird. I assume it's a good connection and no cooling effect? You could always take the sender off and dunk it in either hot or cold with a comparison thermometer to ensure its not the thermocouple issue and then gauge accuracy

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Originally Posted by PeeBee

That sounds a bit weird. I assume it's a good connection and no cooling effect? You could always take the sender off and dunk it in either hot or cold with a comparison thermometer to ensure its not the thermocouple issue and then gauge accuracy

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I did check it in hot water before installing it. The lugged sensor is clamped directly to the filter closer to the threaded end, maybe it should be closer to the end?

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No that should be fine

I'll keep an eye on it over our new year holiday and note back.

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