TM2 Average Temperature Readings

[Jason789]

Hello,
Just looking for feedback on average head temperature readings for a TD5 from a TM2 Temp/low water sensor.
I have just overhauled my cooling system with genuine parts(new radiator-old one was leaking, new t/stat, replacement of all hoses-more than half of them were leaking and a new water pump-old one was clogged with waxy crud in the bottom half and small gallies leading away from the pump were blocked) all sealed with aviation gasket cement. I also gave the air con condensor a blast/clean out aswell as the transmission cooler, the reason being an over heating episode travelling between melbourne and the Goldcoast.(intercooler had a clean inside and out also)
What a job!!!! but well done and I have a sealed cooling system that no longer leaks.
The temperature readings don't appear to be any different than before the overhaul, so I was wondering what average head temp readings people were getting,
1)unloaded driving without a/c.
2)unloaded driving with a/c.
3)towing a trailer/loaded without a/c.
4)towing a trailer/loaded with a/c.
Is there anything that I missed??
Feedback by anyone with a TM2 or similar sensor would be most appreciated.

Cheers,

Jason

[d@rk51d3]

90 degrees average, give or take a couple depending on the situation.

[robbotd5]

My sensor is bolted up to the front rhs of the head to a bolt that screws into the block. It is quite long. From this I get readings ranging from low 70's to 88 degrees on a hot day with the a/c on.
Regards
Robbo

[101RRS]

Depends whether the sensor is mounted - temperature on the display in itself is not important - what is, is noting the temp when the engine is at normal operating temperature the setting the alarm at 10 - 20 degrees hotter.

On my V8 petrol I had the sensor at the front of the head in the airflow caused by the fan - indicated 70 degrees when water temp was 80 - I have now moved the sensor further along the engine where the cooling impact of the fan is reduced - haven't tested it yet.

So - if your standard operating temperature is xyz then stick with that - mine did not change much except when stopped in traffic when it went up 5 degrees. On the road it stayed within 1 degree of 70 irrespective of what I was doing but water temp was rising and falling.

Garry

[Jason789]

Hello,
Thanks for the replies.
I'm getting about 90 degrees average temp(the sensor is mounted on the left hand side of the head near the rear of the motor) , I thought that maybe it should have dropped a little given the new radiator and a water pump that wasn't blocked with crud.
It seems that these TD5 motors reach a critical head temperatures reasonably quickly when given a bit of a hard time.
Perhaps ignorance is bliss in relation to head temps.

Cheers,

Jason

[dswatts]

Jason,
my sensor is in about the same position as yours. Averages around 80-84.
when air temps exceed 40, aircon going flat out, sitting on 110kmh will get up around 85-88.

Dylan

[Jason789]

Hello,
a few cordials and silly thought later.
Perhaps the sensor is getting false readings through radiant heat from the turbo and exhaust manifold(as the sensor is in the direct vicinity of both them). I'm thinking that an alternative mounting point of the heat sensor could provide more accurate/stable reading.

Are there any alternative sensor mounting points that anyone has used that are a bit further from the turbo and exhaust manifold??
I will look for one myself in the light tomorrow but suggestions are always good.

Cheers,

Jason

[cjc_td5]

I have a D2a TD5 Auto with approx 146K on the clock and have had a TM2 monitor installed for a couple of months. The temperature sensor is mounted in the recommended position at the rear-left (passenger side) of the head.

Around town the temperature normally sits around 85-90 degrees, rising to 92 sometimes when idling at an intersecion etc.
On the highway when towing a 750kg camper trailer, it will sit on about 89-92 degrees. On a long, steep grade, particularly when the overdrive is not locked in, it can get up to 98 degrees but will come down again quickly when running down the other side of the hill.

Last weekend we did some beach work down south (Yeagerup Dunes) and it was sitting on about 92-93 when ploughing along the softish beach. When we tackled Calcup Hill, a very long steep sand climb, the temperature rose to 102 degrees which is where my alarm is set, a couple of minutes at a fast idle quickly brought the temperature back down to 92 degrees and off we went again. Through all of the above the OEM temperature gauge remained unmoved.

In all of above situations, the ambient temperature would be >25 degrees, sometimes >30 degrees.

Can anyone tell me what temperature on the TM2 is into danger territory with a TD5???

Certainly on the weekend, I would not have had any idea of the changing block temperatures if depending on the OEM temperature gauge. I don't know if the additional information from the TM2 is good for my sanity or not!!

Cheers,
Chris

[Jason789]

Can anyone tell me what temperature on the TM2 is into danger territory with a TD5???


Cheers,
Chris

Hello cjc_td5

I got told(forgive me, I have forgotten their name) that 105 degrees is the correct temp to set the head temp alarm at, as this is the temp that the coolant starts to boil at, therefore creating hot spots in the head wherever the coolant does start to boil.

I have my alarm set at this temp(105 deg)

PS. If anyone has information to support or denegrate this information, it would be most appreciated.

Cheers,

Jason

[cjc_td5]

Hello cjc_td5

I got told(forgive me, I have forgotten their name) that 105 degrees is the correct temp to set the head temp alarm at, as this is the temp that the coolant starts to boil at, therefore creating hot spots in the head wherever the coolant does start to boil.

I have my alarm set at this temp(105 deg)

PS. If anyone has information to support or denegrate this information, it would be most appreciated.

Cheers,

Jason

Thanks Jason.
Looks like I might have come close to a boil then (with 102 degrees). This raises two issues with me, one that the OEM temperature gauge gave no indication whatsoever of any issues, and two that I would think that the cooling system should be good enough to not get to that high a temperature in the first place. Looks like I have some investigations to do re a radiator rodding/replacement etc.

Thanks,
Chris

[101RRS]

A pressurised coolant system will get much hotter than 100 degrees.

The TM2 cannot measure the exact temperature of the head as it is mounted externally so the temperature it displays at the sensor is a measure of a number of items but mainly head temperature moderated by other factors - eg heat from the exhaust if nearby making it higher or if in the airflow from the fan a bit lower. The actual temperature displayed is almost irrelevant by itself that is why the instructions do not have an indicative temperature - if I remember correctly they say to drive your vehicle so it gets to operating temperature, note the temperature on the TM2 display and set the alarm at 15 higher.

On my TM2 on my V8, the temp stays at 71 when the engine is running normally and water is 85 but clearly the internal temp of the head will by much hotter. My water temp stays relatively constant where the TM2 can go up to 82 on a hot day idling in traffic - the coolant temp does not change as the thermostat is opening and allowing more coolant through the engine - this is not to say the engine is not actually getting hotting. If you had an oil temp gauge you would most likely find it would be getting hotter as well as the TM2.

So don't worry too much about the temp readout in itself but note the changes in temp - set the TM2 to about 15 hotter than the every day operating temp showing on the TM2.

Garry

[cjc_td5]

A pressurised coolant system will get much hotter than 100 degrees.

The TM2 cannot measure the exact temperature of the head as it is mounted externally so the temperature it displays at the sensor is a measure of a number of items but mainly head temperature moderated by other factors - eg heat from the exhaust if nearby making it higher or if in the airflow from the fan a bit lower. The actual temperature displayed is almost irrelevant by itself that is why the instructions do not have an indicative temperature - if I remember correctly they say to drive your vehicle so it gets to operating temperature, note the temperature on the TM2 display and set the alarm at 15 higher.

On my TM2 on my V8, the temp stays at 71 when the engine is running normally and water is 85 but clearly the internal temp of the head will by much hotter. My water temp stays relatively constant where the TM2 can go up to 82 on a hot day idling in traffic - the coolant temp does not change as the thermostat is opening and allowing more coolant through the engine - this is not to say the engine is not actually getting hotting. If you had an oil temp gauge you would most likely find it would be getting hotter as well as the TM2.

So don't worry too much about the temp readout in itself but note the changes in temp - set the TM2 to about 15 hotter than the every day operating temp showing on the TM2.

Garry

Thanks Garry. Point taken re accuracy of the absolute temperatures, as opposed to using the TM2 to assess changes in relative temperatures.

My main concern is that in hard going I can push the "normal temp plus 15 degrees" envelope. I am trying to assess whether this means I have a cooling system fault somewhere that I need to chase down. The "fault" is obviously not a "show stopper", but does appear to reveal short-comings in the cooling system performance when the engine is working hard.

Cheers,
Chris

[101RRS]

You can obviously test the sender and gauge to make sure they are doing what they are supposed to do - however as a general statement if the cooling system is full and not loosing water and you are satisfied that the gauge and sender are OK you could assume the cooling system is Ok - the issue you initially raised indicates to me that your system is most likely OK and the water is taking the heat away as it should. If you lost a bit of coolant I can almost guarantee that in the same situation that you decribed then the coolant temp would rise.

My Freelander temp gauge always sits on midway - no matter what the outside temp and load on the engine. All of a sudden I noticed the gauge getting a little hotter - just a little - I ignored it - later it started getting higher - there was a small split in a hose that only allowed coolant to escape when hot - so the gauge will move with reduced cooling capacity.

So - as long as you are not loosing fluid, there is no oil in your coolant, nothing is dripping, and you system is not being pressurised (bubbled in the coolant) and the gauge stays on normal (with full coolant levels), particularly when working hard then you do not have an issue.

But like you - I always watch what the TM2 is doing - was really surprised how much it rises when stopped for long periods in heavy traffic (lack of airflow) - but the coolant stays on normal and does not rise with the TM2.

Good luck with it.

Garry