How hot is HOT!

[jonesfam]

A couple of weeks ago I was driving up the Palmerston Highway from Innisfail back to Ravenshoe.
As I was on my own & the traffic was light I thought I will just try to maintain as close to 100kph as I can, allowing for some tight corners, to see how Ye Olde D3 TDV6 is going.


I also have a Scan gauge 2 installed.


So, under normal flat road driving, almost any load at 100kph & with any ambient temperature the S gauge reads between 88 & 92.
Going up the Palmerston I was getting readings, when I could look, up to 119. The cars Temp gauge did not move 1mm during the whole drive.


So, how much above normal temp does the car have to get before the in car gauge will warn you? Seems funny to me that the actual temp went up about 29 but the gauge didn't move.


Jonesfam


PS She went up very, very well.

[Graeme]

I can't quite recall the full significance but 121 was a threshold for the TD5 in the D2.

[Eevo]

I can't quite recall the full significance but 121 was a threshold for the TD5 in the D2.

coolant under pressure boils about 130??

[Graeme]

127 deg is when the TD5 D2 temp gauge needle drops to the bottom and turns on the overheated LED in the gauge. However by that time the head gasket was done and risked a warped head. The WSM dcuments the duty cycle of the temp signal from the ecm for a couple of temps with the highest one at 121. The Bosch temp sensor is only accurate up to 130 deg.

[shanegtr]

I was recently towing my camper and had my IID tool pluged in to monitor some temps. With flat road travelling the coolant temp was reading high 80s - low 90's. Going up hills I was just cracking 100deg. Engine oil temp around 112 with the higher loads, but that dropped of to mid 90's on the flats

[DiscoDB]

At 119 degC you would have been very much on the border line of going into limp mode. The temp gauge in a modern car is more like a 4 position indicator (cold / warm / normal / too hot). The halfway point represents the car is in the normal allowable range. This will be at least a 30-40 deg band where it does not move. Once it does start moving upwards again then you are into overheat range and need to back off urgently (or the ECU will intervene anyway and go into limp mode).

Of course if you did not have the ScanGuage then you have been oblivious to all of this - which is what the manufacturers want so as not to alarm you to the normal variations you could see.

Now that you do know it was seeing 119, in my opinion this is too high. Sure it did not boil, but there was very little margin remaining. I would be checking you don't have an issue with the cooling system (or back off next time).

[NomadicD3]

Hi All,
Interesting topic Jonesfam and I hope you don't mind but I'd like to investigate this a bit more.
So.... What should people do to by way of preventative measures?
changing the coolant regularly? Given many coolants with anti freeze/boil have 3 year/100 thousand k "Advertised" life expectancy. What do people think is a reasonable time/distance to change the coolant.
What other actions would people suggest Jonesfam do to reduce the temp?
pull the radiator and have it cleaned and pressure tested? I'm not aware of any "in car" radiator cleaning products.
Has anyone replaced their radiator due to old age etc? If so @ how many k's?
Any other ideas/suggestions?

[Graeme]

I set-up my home-grown TD5 D2's temp monitor to go full alarm mode at 118 and also close the inlet throttle valve to allow not much more than idle until the coolant temp got back down to 115. It never got to 118 but saw 115 one quite hot day idling along in top gear so dropped a gear to get the revs up for better cooling.

[LandyAndy]

I would also question the accuracy of the tools readout.
I had an early Nannycom on my D2,I used it in instrument mode consistantly.From tome to time it would throw 160degC+ temps for a short time,sometimes -160degC temps.
I put it down to interference on the system,guessing its possible in these newer beasts too.
Andrew

[LandyAndy]

Hi All,
Interesting topic Jonesfam and I hope you don't mind but I'd like to investigate this a bit more.
So.... What should people do to by way of preventative measures?
changing the coolant regularly? Given many coolants with anti freeze/boil have 3 year/100 thousand k "Advertised" life expectancy. What do people think is a reasonable time/distance to change the coolant.
What other actions would people suggest Jonesfam do to reduce the temp?
pull the radiator and have it cleaned and pressure tested? I'm not aware of any "in car" radiator cleaning products.
Has anyone replaced their radiator due to old age etc? If so @ how many k's?
Any other ideas/suggestions?

There are "MUST FOLLOW" radiator clean out procedures in the D4 book of words following off-roading,guessing the D3 would have the same.
I have lots of overheat/no aircon issues in my grader,especially cutting fire breaks thru stubble at bushfires.The chaff blocks the radiators and is held there by the suction of the hydro motor run cooling fan.
It only takes a minute or 2 to brush out what you can with a bannister broom whilst the hand throttle is at full rpm.No issue with moving parts to get tangled in.Problem is we have had both the graders de-rate when we cant get out and have a tidy up as the flames are too close,scary stuff
Andrew