Just changed the ATF and .....

Lord of Hog · 15th December 2018, 09:45

I've finally got round to changing the ATF on my X plate 2.5, and not before time by the look of it. The stuff that came out was the colour of treacle and I suspect was what went into it at Cowley just under 100k miles ago. For the purposes of the ongoing debate let it be recorded that I used "Westway N402 Jatco" fluid.

It now runs like a dream. However it does so at 2° warmer than before (92° in normal use as opposed to 90° previously). My first thought is that new fluid allows more efficient transfer of heat from box to oil cooler and thus to cooling system. Anyone got any thoughts on the subject?

kaiser · 15th December 2018, 15:43

90 and 92 degrees?
I really doubt that can be read with any accuracy/confidence.
If, which I doubt, there is any difference, then I can only assume that it could be caused by the new oil having a higher viscosity, compared to the old?

But really, I don't think there is anything in it!

COLVERT · 15th December 2018, 18:29

Lord of Hog · 16th December 2018, 09:07

That's pretty much what my mechanic friend told me when I finally got hold of him. He reckons it has something to do with ATF absorbing a little water as it degrades with age.

Proves what I've said for a long time: the factory temperature gauge makes you paranoid and the digital version makes you even more paranoid

15th December 2018, 09:45	#1
Lord of Hog Gets stuck in Rover 75 2.5 V6 in Wedgwood Blue Join Date: Dec 2015 Location: Felbridge, East Grinstead Posts: 982 Thanks: 250 Thanked 294 Times in 206 Posts	Just changed the ATF and ..... I've finally got round to changing the ATF on my X plate 2.5, and not before time by the look of it. The stuff that came out was the colour of treacle and I suspect was what went into it at Cowley just under 100k miles ago. For the purposes of the ongoing debate let it be recorded that I used "Westway N402 Jatco" fluid. It now runs like a dream. However it does so at 2° warmer than before (92° in normal use as opposed to 90° previously). My first thought is that new fluid allows more efficient transfer of heat from box to oil cooler and thus to cooling system. Anyone got any thoughts on the subject? __________________ Conformity is not morality. Consensus is not truth.

15th December 2018, 15:43	#2
kaiser This is my second home 75 Tourer 2.5 Auto, 1.8T, 75V8ZT Join Date: Jun 2007 Location: Johannesburg ZA Posts: 6,200 Thanks: 1 Thanked 859 Times in 613 Posts	90 and 92 degrees? I really doubt that can be read with any accuracy/confidence. If, which I doubt, there is any difference, then I can only assume that it could be caused by the new oil having a higher viscosity, compared to the old? But really, I don't think there is anything in it! __________________ Worth his V8 in gold

16th December 2018, 09:07	#4
Lord of Hog Gets stuck in Rover 75 2.5 V6 in Wedgwood Blue Join Date: Dec 2015 Location: Felbridge, East Grinstead Posts: 982 Thanks: 250 Thanked 294 Times in 206 Posts	That's pretty much what my mechanic friend told me when I finally got hold of him. He reckons it has something to do with ATF absorbing a little water as it degrades with age. Proves what I've said for a long time: the factory temperature gauge makes you paranoid and the digital version makes you even more paranoid __________________ Conformity is not morality. Consensus is not truth.

15th December 2018, 18:29	#3
COLVERT This is my second home R75 Saloon. Join Date: Feb 2009 Location: France/or Devon. Posts: 14,003 Thanks: 3,851 Thanked 2,167 Times in 1,816 Posts