Mossberg Posted June 23, 2022 Share Posted June 23, 2022 I want to fit a cylinder head temperature sensor to my 300tdi - something similar to the Engine Watchdog TM1 or 2. I want to monitor the Engine temperature and I find the stock temperature gauge pretty naff. As it's a 300tdi I don't like the fact that coolant loss renders the temperature gauge useless until the engine is cooked and would like to fit a head temperature sensor for peace of mind. So, where is it best to fit the sensor as you fit it to an existing bolt. What is a good location and a safe bolt to use. If anyone already has one successfully fitted then a photo would be great if possible. I already have a low coolant alarm fitted but would prefer to have both. As always, thanks for any help you can give. Best regards Mick Quote Link to comment Share on other sites More sharing options...
CliveT Posted June 25, 2022 Share Posted June 25, 2022 Hiya, I've just installed a sensor on my 300tdi. I put it on a bolt right at the rear of the block which holds the lifting eye on. It had a metal cable clamp already on it. It's easily accessible from above, and convenient for routing the wire. Quote Quote I don't know if this is the best place thermically (is that a word?), but it's shielded from cooling effect of the airflow. It may not give a precise reading of the engine temperature, but it should detect any untoward increase which should trigger an alarm. My gauge is programmable so I'll have to experiment with the settings. I should point out that I've only just done this and don't yet have the gauge installed, so my reasoning my be completely flawed! Hopefully someone with actual experience can chip in. Clive Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 25, 2022 Share Posted June 25, 2022 Really needs to be much more close to where the water is flowing in the head, where you have it it could take too long for a change in temp to be detected to save your engine... No bolt suggestions (not familiar with stinky oil burners), but as close as possible to water flow in the head is what I would aim for. Quote Link to comment Share on other sites More sharing options...
cackshifter Posted June 25, 2022 Share Posted June 25, 2022 There is a sensor already, used by the EGR, that varies in resistance as it warms. Quote Link to comment Share on other sites More sharing options...
Mossberg Posted June 25, 2022 Author Share Posted June 25, 2022 Thanks Clive, that really is appreciated. May I ask which gauge you went for? Bowie, I am not sure how the water temperature will affect this as this the gauge is more likely to be required in the case of coolant loss due to the water pump position meaning it stops pumping water around, which is a flaw of the 300tdi. I am eager to hear of Clive's experience when he gets the gauge in. I presume his has an adjustable alarm so he can start low and work up. If the gauge goes up in deg C then hopefully a logic can be established for standard use, under load, etc. Cackshifter, I need to investigate my engine to see if it has the EGR sensor in it. I think it will do as i think its a Disco engine in it. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 25, 2022 Share Posted June 25, 2022 Fair point, suppose what I was trying to say more so was that the bolt boss chosen is a poor location as it is miles away from where the combustion is happening. Quote Link to comment Share on other sites More sharing options...
Mossberg Posted June 25, 2022 Author Share Posted June 25, 2022 8 minutes ago, Bowie69 said: Fair point, suppose what I was trying to say more so was that the bolt boss chosen is a poor location as it is miles away from where the combustion is happening. Thanks Bowie, I think a bit more investigation may be useful. Clive's actual real time feedback will be great when he gets the gauge fitted. Quote Link to comment Share on other sites More sharing options...
CliveT Posted June 25, 2022 Share Posted June 25, 2022 Yes, Bowie, on reflection it isn't the best of places. Do you think I could use one of the bolts on the egr blanking plate? That would be closer to the centre of the engine. This is the gauge I bought from gauge innovations on eBay. They're in Oz. There's various options of sensor configuration, and a 52mm round one too. It is programmable for when the alarm goes off. I figured I'd have to experiment based on different driving conditions. Quote Link to comment Share on other sites More sharing options...
Mossberg Posted June 25, 2022 Author Share Posted June 25, 2022 38 minutes ago, CliveT said: Yes, Bowie, on reflection it isn't the best of places. Do you think I could use one of the bolts on the egr blanking plate? That would be closer to the centre of the engine. This is the gauge I bought from gauge innovations on eBay. They're in Oz. There's various options of sensor configuration, and a 52mm round one too. It is programmable for when the alarm goes off. I figured I'd have to experiment based on different driving conditions. That's the one I fancy getting. Did you get stung for customs charges? Quote Link to comment Share on other sites More sharing options...
CliveT Posted June 25, 2022 Share Posted June 25, 2022 I live in France, so not sure it would be the same, but I paid approx £107 for the unit, £16 delivery and £25 vat. That was all prepaid on eBay. When it was delivered the postie asked for 32 euros (£27 ish), assume that was import duty. It's not the cheapest gauge around, but it seems well designed, and is programmable with alarms. Plus it looks cool! Quote Link to comment Share on other sites More sharing options...
Mossberg Posted June 26, 2022 Author Share Posted June 26, 2022 Ah, thanks Clive, I think you have mentioned that before! Have you fitted the sensor to the transmission yet - if you have could you post up a photo. I am keen to see your results when you get it wired up. I suppose with the sensors bolting on it shouldn't be too difficult to move the position. I will continue with my quest to find out where others have fitted it (the Australian guys seem keen to fit them on the 300tdi) and if I find out I post it here. Quote Link to comment Share on other sites More sharing options...
CliveT Posted June 26, 2022 Share Posted June 26, 2022 My complete transmission is on the floor at the moment, taken out to change the clutch. While it's out there's so much space underneath that I'm taking time to do other things too. Treating rust, sump leak, tidying wiring etc etc. So it will be a while yet before I'm back on the road. There's a couple of options for the sensor bolt, but not decided yet. I'd be interested to know what you find out. Could ask Gaugeinnovations themselves if they have experience of sensor location? Cheers Quote Link to comment Share on other sites More sharing options...
Mossberg Posted June 26, 2022 Author Share Posted June 26, 2022 Hi Clive I did ask and they came back quickly but unfortunately couldn't help. The place to ask seems to be on the Australian forum, aulro, but you only get 3 months free access and after that you can't post anymore without subscribing and I am always reluctant giving those kinds of details on the net. There are a few posts on there about it but unfortunately I can't see the images. They probably use this kind of kit more due to the higher temperatures they are used to driving in. I hope all your jobs go well. I have a bit to do myself this week, notably changing my front axle case and replacing my bulkhead outriggers - both jobs I am apprehensive about. Quote Link to comment Share on other sites More sharing options...
Mossberg Posted February 21, 2023 Author Share Posted February 21, 2023 CliveT, did you manage to fit your gauge? Would be interested to see how you went on. I fancy one of those gauges but the exchange rate has pushed it above the customs charge threshold. I Should have purchased it when I first posted. However I have purchased a Durite gauge and sender which I intend to install as a direct replacement for the land rover one. It has a graduated scale rather than cold/warm/hot/goosed! Quote Link to comment Share on other sites More sharing options...
western Posted February 21, 2023 Share Posted February 21, 2023 300Tdi EGR temp sensor is halfway along left side of cylinder head top face, there should be a blanking plug or a undrilled & unthreaded raised face Quote Link to comment Share on other sites More sharing options...
Mossberg Posted February 22, 2023 Author Share Posted February 22, 2023 Thanks Western. What type of sensor would you recommend for that location and would that work if i lost coolant? Quote Link to comment Share on other sites More sharing options...
Tobias Posted February 22, 2023 Share Posted February 22, 2023 I hear what you say about loss of coolant making a coolant sensor ineffective, but I believe you are mixing two problems. Problem 1, loss of coolant causing dry running in cylinderhead (and non-functioning wate temperature measurement) You fix this with a water loss alarm, which you have. So given that the alarm works and you stopp to fix any problem the alarma indicates, you always have water in the coolant galleries. Problem 2, coolant water temperature measurement. I agree that the stock gauge is carp. I have replaced the thermostat housing bung with a brass one, drilled and tapped for coolant temp sensor for an aftermarket gauge. Worked fab! I have also mounted a gauge inovations one on another 300tdi and there i wedged it between thermostat housing and bolt, good connection with the aluminium of the housing, which is in good contact with the water in the thermostat housing. Trying to measure cylinderhead temperature to catch coolant loss is too slow, in my opinion. You are trying to solve both problems above in one go, and in reality solve none. T Quote Link to comment Share on other sites More sharing options...
Mossberg Posted February 22, 2023 Author Share Posted February 22, 2023 Thanks Tobias. I have the coolant alarm fitted and it has saved me once when my rad sprang a leak. I will fit the Durite sensor and gauge and see how that responds. Quote Link to comment Share on other sites More sharing options...
CliveT Posted February 23, 2023 Share Posted February 23, 2023 Hi Mossberg, yes have the gauge fitted and working. Sensor fitted to the rear of the engine by the lifting eye. Think I sent a photo before. To be honest I've not given it much attention and haven't set the alarms. You know how it is - always something else to think about! I seem to remember that the engine reading is about 70deg on an average run at say 55mph. That's obs because the sensor is badly placed, but could be useful if I set the alarm at a correspondingly low level. I will move the sensor when I get round to it. Small point on that gauge. It does remember the highest temp reached on the journey, but resets itself every time. You have a few moments after switching off to make a note before the screen goes blank. Quote Link to comment Share on other sites More sharing options...
elbekko Posted February 24, 2023 Share Posted February 24, 2023 On 2/22/2023 at 10:32 AM, Tobias said: Problem 1, loss of coolant causing dry running in cylinderhead (and non-functioning wate temperature measurement) You fix this with a water loss alarm, which you have. So given that the alarm works and you stopp to fix any problem the alarma indicates, you always have water in the coolant galleries. I'm not so sure about that. It's been about a decade since I struggled with the cooling system on my 300TDi, but I remember there being a huge air bubble in the cylinder head (about where the extra sensor would go), that didn't affect the stock gauge nor the level sensor. An extra sensor probably would've shown something was wrong, at least. The only way I knew then was if there was no heat coming from the heater - then followed by the low coolant lamp IIRC. Quote Link to comment Share on other sites More sharing options...
Tobias Posted February 24, 2023 Share Posted February 24, 2023 4 hours ago, elbekko said: I'm not so sure about that. It's been about a decade since I struggled with the cooling system on my 300TDi, but I remember there being a huge air bubble in the cylinder head (about where the extra sensor would go), that didn't affect the stock gauge nor the level sensor. An extra sensor probably would've shown something was wrong, at least. The only way I knew then was if there was no heat coming from the heater - then followed by the low coolant lamp IIRC. Did this air bubble appear after a while of running? I've never seen air bubbles appearing in a coolant system after it has been running at proper level for a significant time. Unless coolant is lost somewhere. While removing air after a full or partial refill of the coolant system, I can easily see air causing all sorts of problems, but after a few hot-cold cycles and verifying that the heater is fully hot and no loss of coolant in the reservoir, I've never experienced air bubbles appearing. The extra sensor you mention is the EGR-sensor? maybe adding a valve there for bleeding is beneficial? T Quote Link to comment Share on other sites More sharing options...
elbekko Posted February 24, 2023 Share Posted February 24, 2023 13 minutes ago, Tobias said: Did this air bubble appear after a while of running? I've never seen air bubbles appearing in a coolant system after it has been running at proper level for a significant time. Unless coolant is lost somewhere. While removing air after a full or partial refill of the coolant system, I can easily see air causing all sorts of problems, but after a few hot-cold cycles and verifying that the heater is fully hot and no loss of coolant in the reservoir, I've never experienced air bubbles appearing. The extra sensor you mention is the EGR-sensor? maybe adding a valve there for bleeding is beneficial? T Both - the RRC had a less than ideal coolant system layout with the header tank lower than the top of the block, so a huge pain in the behind to bleed. And then later with cracked heads/cracked block as well. The EGR sensor, indeed. A valve for bleeding there might be useful, yes. I wonder if some sort of "steam port" setup from there would be beneficial. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.