Hi all,
I decided to do some checking on what live values are like with my iidtool so that in the unlikely event of something going wrong, I would have some idea of what things were before all hell broke loose.
So where better to start than with the dreaded transmission oil temperature.
Last night after driving in to work I checked it and got a reading of 108'C. This morning befor starting my journey home (25 miles) I stuck the IIDTool on and monitored it for my journey.
First 3 miles was urban driving 40mph max, series of roundabouts and a few sets of trafic lights, Temp had reached 78'C
Next 3 miles was constant 50mph and temp reached 90'C
Next 17 miles was constant 65mph and temp peaked at 100'C
last 2 miles was roundabout, village, stop at traffic lights, back road drive at 30mph x 1 mile to home. Temp =104'C

Anyone know is this a sigh of overheating or is it normal....ish
Sounds a bit high when you read the stuff on oil specs and optimal operating temperature of ATF been 80'C

Any thoughts? Declan
2003 FFRR Vogue 4.4 V8
97 Defender 90 300 TDi

Maybe a tad high, last time I checked mine it was around the 100 mark when fully warm which does take a while to get to....  Pete

__________________________________________________
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Thanks Pete, Have done another 25 miles or so mixed driving this morning and its sitting around 103'C peaked at 105'C. Will be doing longer trips next week south of Ireland so that should be a good test for it, plenty of steep hillclimbs and gear shifting. Declan
2003 FFRR Vogue 4.4 V8
97 Defender 90 300 TDi

Well after monitoring my gearbox oil temp for the last few days, its operating around the 100'C which had me thinking strongly of removing my radiator and oil cooler and flushing them out etc to see if I could lower the oil temp,,,,
AND THENNNNNN ... I NOTICED ..........
The Oil Temp always started 20'C above what my external temp dash reading was so my oil temp sensor is reading 20'C high. That means it's running under normal conditions around the 80'C which is the optimum operating temp for ATF.  Declan
2003 FFRR Vogue 4.4 V8
97 Defender 90 300 TDi

100deg is what the oil should be running at, another reason to change it regularly... it sets off the overheat around the 130deg mark...

Oil in the sump or gearbox stays warm all night, especially in this weather... leave it a few days and it will be a similar temp to ambient...  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

 Declan
2003 FFRR Vogue 4.4 V8
97 Defender 90 300 TDi

Declan303 wrote:

Well after monitoring my gearbox oil temp for the last few days, its operating around the 100'C which had me thinking strongly of removing my radiator and oil cooler and flushing them out etc to see if I could lower the oil temp,,,,
AND THENNNNNN ... I NOTICED ..........
The Oil Temp always started 20'C above what my external temp dash reading was so my oil temp sensor is reading 20'C high. That means it's running under normal conditions around the 80'C which is the optimum operating temp for ATF.

Don't think I have a 105'C thermostat. I also have been monitoring the coolant temp and the radiator coolant temp.
The radaitor coolant temp starts to rise when the Colant temp hits 84'C so I'm assuming thats when the thermostat opened. The coolant temp then stays at 90'C approx when on open road ad saw it climb to 94'C when doddling along in slow moving traffic. The radiator coolant is at about 50'C on open road and saw it climb to 70'C in slow moving traffic but I'm sure that can vary greatly with type of driving and external temperature.

And just for a bit of entertainment ..... There is a live value under "Transfer Box" --Gearbox Temperature.
Well mine was at -17'C this evening before I started my journey to work. Yeah thats what I said "MINUS" 17
 Declan
2003 FFRR Vogue 4.4 V8
97 Defender 90 300 TDi

Interesting, you have a very wide temperature range?
The thermostat is supposed to iron this out.......ie it should close once the coolant is "cooled" in the radiator below the thermostat fixed set point, which on the standard thermostat is 105c.
I have just replaced my standard stat with an 85c stat (although I dont use your diagnostic tool) I use the on dash temp gauge in message centre) which keeps my coolant at 90c +/- 3c. Prior to this I was seeing an average of 108c.

I suspect there are more than 1 temperature probes on the coolant circuit.

Out of interest ID II tool versus the message centre temp what do you see?

I haven't used the message center so will have a look. Mine is same as yours then, sitting at 91'C +/- 3'. Not sure what you mean when you say about the wide range. Its the Radiator temperature that is varying as I speed up on open road and slow down in traffic but is that not to be expected. Engine temp stays pretty constant which I assume is the job of the thermostat. Declan
2003 FFRR Vogue 4.4 V8
97 Defender 90 300 TDi

Yes, thats why I say there must be 2 temperature probes possibly more.
One at the radiator and one that I know of for sure and that sits on top of the stat/waterpump.
Im guessing the radiator is holding a store of cooler water and the stat opens up to let it through for cooling as needed.
Contra to the way I believed the system worked.......ie all the coolant would be roughly the same temp weather in the engine side of the circuit or the radiator.
Im is Aussie, I believe these engines run WAY way to hot for our conditions thats why I have fitted a cooler stat.
Im very happy with the results, seeing temps under 100c gives me piece of mind should I loose a hose, especially on a 40c+ day.

Yeah, the reason the thermostat is there is to ensure the engine does not run too cold so that even in freezing weather, the engine will go up to 84'C and will be held at that. Declan
2003 FFRR Vogue 4.4 V8
97 Defender 90 300 TDi

There are two temp sensors, one on the outlet from the top of the engine where the temp will be at it's hottest, the other is in the bottom hose where it leaves the radiator, this will be the coolest part of the system...

IID will measure both temps, on board measures the top, high temp one, they will be the same reading...

If you have a standard stat then it is 105deg and your temp will be above 100deg when up to temp, it sounds to me like either yours is stuck open or it has been replaced with a lower one or had the, cheaper, modified stat...

No way would yours run at that temp with the original 105deg stat....

Took mine out totally for several months before fitting the lower temp one and it sat at a similar temp to yours and didn't take too much longer to warm up either... did start to take a lot longer as the ambient dropped to near 0 so I put the modified one in with an 80 deg one in, been fine for 2 years now....

Have tried the 80 deg and the 85 deg and funnily enough it made virtually no difference to the temp it runs at when hot... Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
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"If you have a standard stat then it is 105deg and your temp will be above 100deg when up to temp, it sounds to me like either yours is stuck open or it has been replaced with a lower one or had the, cheaper, modified stat... "

Pete,
Mine has to have a lower one as starting from cold it consistantly opens at 84/85'C. I know because it is at that point when the radiator temp starts to rise.

Declan Declan
2003 FFRR Vogue 4.4 V8
97 Defender 90 300 TDi

That's what I mean, someone has changed it before, seems you already have a lower temp one in there... which is great as it's one of the best things you can do to reduce the under bonnet temps...  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-