My d2a towing coolant tempt

[maxperformance]

Hi mates, I was using my Autel Pro scanner to read live coolant tempt in my D2a towing trip last week.

Day trip, towing 1.2T trailer, about 28 degree ambient, Airconditioner on LOW with level 4, reading tempt in the range 70 - 77oC.

Night trip, towing 3.5T, cool night about 20oC, Airconditioner at 18 on level 2, reading tempt in the range 70 - 82oC.

High tempt related to a few times of using 3rd or 2nd gear up steep hills.

Does this sound right?

[Rok_Dr]

Sounds a bit on the cool side to me.

cheers

Steve

[shack]

I second that, I'd be checking if the sender is faulty first, if that's ok then the thermostat.
The sender can be checked against the one in the fpr.

Cheers
James

[sierrafery]

It doesnt sound right at all to me, the optimal running temp is around 88-90*C for a Td5, lower ECT readings would increase fuelling. Aircon has nothing to do with that, check the fuel temp reading too next time, it should be around 10-15*C lower than the ECT. Yur thermostat might be stuck open... and even then it's a bit low especially with trailer

[PhilipA]

My D2 TD5 EU3 auto nearly always runs at between 82 and 85 C at those temperatures of around 20C.. Measured with a dry sensor located next to the ECU sensor and calibration checked against the ECU sensor using a Nanocom. Largest difference was about 0.2C.

Towing in 32C last week it ran at 85C on the flat and reached a max of 94 on a long climb at 115Kmh.

The thermostat starts to open at 82c and is fully open at 88C.

Mine has done this with an old thermostat and a new one .

I would suggest that under 82C suggests a leak in the thermostat , however under cruise conditions 82C-85C up is acceptable.
Regards PhilipA

[maxperformance]

Here is the shot with 1.2T trailer alone, I stopped to take a photo asap so the tempt would not change.https://uploads.tapatalk-cdn.com/20210316/6b5ddb636a5af047cdd4bafeb90e96c0.jpg

[trout1105]

Something seriously wrong with those readings especially the IAT reading of 67C for that to be accurate it would have to be 60C+ ambiant temp outside the car.

[shack]

Here is the shot with 1.2T trailer alone, I stopped to take a photo asap so the tempt would not change.https://uploads.tapatalk-cdn.com/20210316/6b5ddb636a5af047cdd4bafeb90e96c0.jpgThe IAT is fine, that's in the inlet manifold, looking at that display, if it's correct, I'd say your ECT sender is kaput.

Cheers
James

[discorevy]

The IAT is fine, that's in the inlet manifold, looking at that display, if it's correct, I'd say your ECT sender is kaput.

Cheers
James

X2 , or the reader isn't reading correctly , it can't spell manifold either[bighmmm]

[Tins]

X2 , or the reader isn't reading correctly , it can't spell manifold either[bighmmm]

Perhaps it's dyslexic.

[maxperformance]

LoL. "Mainfold". You catch it. I should claim Autel (although this scanner works really well for cars from 2006, I can't say much on my D2) ;D
X2 , or the reader isn't reading correctly , it can't spell manifold either[bighmmm]

[AK83]

could be a possibility that a previous owner has fitted a cooler(78°C) thermostat in it.

IIRC, such a beast does exist in the wild(can't recall for which vehicle tho) ... so unless you are 100% sure of the vehicles history, don't make assumptions about stuff.

Previous replies could be spot on too tho .. so think of all the possibilities.

If you can see the part No. on the thermostat, at least you can 'Sherlock It', with a bit more certainty.

The part No. for the TD5(and V8 .. and a few other LR vehicles) is PEM100990.

The 78°C stat is supposed to be part No. PEL100110.
I've seen info that this lower temp stat may be a different colour, either grey or black. The normal stat is supposed to be a creamy/pale brown/pooey looking color.
So there's a start .. just the colour could be a hint at what's happening.

Could also be that the Autel is just inaccurately reading the ECT value from the BCU too. Not unheard of .. and maybe a bug in their software that has yet to be identified(or something like that).

There is a table of resistance values that the sensor sends to the BCU, if you have a multimeter you could do two readings to confirm those resistance values. Not hard to do, to confirm the sensors output.

hope that helps.

[Rok_Dr]

Thanks for reminding me. When I had very low temperature readings (maxing out in the low 70's on the nanocom) I traced it back to crappy contracts on the temp sensor. A clean and scrub later, along with renewing the wiring loom conduit across the front of the engine and normal service was resumed.


I second that, I'd be checking if the sender is faulty first, if that's ok then the thermostat.
The sender can be checked against the one in the fpr.

Cheers

Steve

[RobMichelle]

What if the thermostat was replaced with a cooler one ?
Rob

[sierrafery]

Here is the shot with 1.2T trailer alone, I stopped to take a photo asap so the tempt would not change.https://uploads.tapatalk-cdn.com/20210316/6b5ddb636a5af047cdd4bafeb90e96c0.jpg
Hi. Unless the OBD2 protocol is not making tricks with the Td5(which it used to) then something is not OK regarding the ECT and FT readings as the FT should be around 10 degrees less than the ECT that's a fact.

A about statements that anything below 88-90*C ECT reading is OK i must contradict that based on many measurements. My advice is to fit a EGT gauge and compare the readings below and around 90*C(that's the optimal ECT for a Td5) cos the lower the ECT and FT readigns are the more fuel is injected which means higher EGTs than necessary if the reality is different so additional ECT gauge is compulsoruy cos the factory one stays at the middle between 70 -120*C so too rough .

[Bohica]

Borrow Nanocom!! cross check the data.

[shack]

Borrow Nanocom!! cross check the data.Actually that's probably the best idea, it could simply have the readings the wrong way round, if that were the case - it's still too cold, but then that would narrow the problem down to a cooling system issue.

Cheers
James

[PhilipA]

If the temperature sensor is crook then Nanocom will tell the same story as the ECU.
You have to have a different sensor to know.
Maybe just use a laser sensor onto the gooseneck next to the temperature sensor.

It is pretty common for the injector plug on the temperature sensor to get dirty and give a low reading so remove it and clean it with electronics cleaner first up, then see if the reading is different.

Regards PhilipA

[maxperformance]

I don't have access to see number on thermostat but from your ideas I think it is the colour of a genuine one? I will try to clean sensor plug this weekend.https://uploads.tapatalk-cdn.com/20210318/26b32f48e09b77ac87daab51fe51b54a.jpg

[shack]

Over the past 24 months I've probably replaced 2 MAP/IAT sensors that were faulty, advised on others that also were, changed numerous MAF's, and now I think a couple of ECT senders and a wastegate modulator.

I think it's getting to be about that time of life.... So I wouldn't be surprised at all if many are failing, and honestly, 20 years old? Not a bad effort.

Cheers
James

[AK83]

I don't have access to see number on thermostat but from your ideas I think it is the colour of a genuine one? I will try to clean sensor plug this weekend.

Yep. photos can be deceiving in terms of colour accuracy, but that one looks to be standard fare.

So, start looking more towards the sender unit.
If you don't have one, IR thermometers are handy tools to have.. as said .. point it at the senders coolant outlet port.

If you get a hold of a nanocom and it reads the same .. could be an actual issue then.

[maxperformance]

Over the past 24 months I've probably replaced 2 MAP/IAT sensors that were faulty, advised on others that also were, changed numerous MAF's, and now I think a couple of ECT senders and a wastegate modulator.

I think it's getting to be about that time of life.... So I wouldn't be surprised at all if many are failing, and honestly, 20 years old? Not a bad effort.

Cheers
James

I never need to change MAP sensors, but did need to change MAF twice. Few years ago I bought one generic MAF for my 99 Auto Td5 and it worked very well. However, on my current 03 Manual Td5 the generic MAF sensor just last 1 day (bad luck) then I pull the trigger to get a VDO one and it has been working as it should.

[Kaaaiju]

What did the vdo set you back?
I never need to change MAP sensors, but did need to change MAF twice. Few years ago I bought one generic MAF for my 99 Auto Td5 and it worked very well. However, on my current 03 Manual Td5 the generic MAF sensor just last 1 day (bad luck) then I pull the trigger to get a VDO one and it has been working as it should.

[maxperformance]

What did the vdo set you back?

I got it off eBay from a seller who still is selling new and genuine VDO one. I believe that I was paying like $230 and received it quickly via Express. Just did not like the way he packed the box as it was almost opened at arrival, but definitely the MAF sensor works awesome since then.