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jules

Member Since: 13 Dec 2007
Location: The Wilds of Warwickshire
Posts: 4571

2014 Freelander 2 SD4 SE Auto Firenze Red

? over cooling ? thermostat stuck open

Today I was checking transmission oil temp and engine coolant temp, whilst driving up the A38 and back (about 40 miles), using my OBDII dongle and Torque Pro app.
The engine coolant temp stayed at 79-80C irrespective of road speed etc. (as did the transmission oil temp). This seems rather low to me, I would have expected it to be nearer 90C. I wonder if the thermostat is stuck open a bit ?

What is the normal engine coolant temperature in cold weather (0C outside) ?

I could only find this thread
http://www.freel2.com/forum/topic29262.html?highlight=thermostat
which indicates a temp of 81 to 83 as acceptable. What do others think?

FWIW The digital temp gauge remained bang in the middle (but we know its not a linear gauge and has a middle flat spot designed in to stop small changes in temp showing on the gauge and worrying customers) Jules

31st Jan 2019 8:54 pm

alex_pescaru

Member Since: 12 Mar 2009
Location: RO
Posts: 4640

It's OK. Mine, during long cruises, both stay at about 82 degrees C.
And it's normal to have both the same temp as the transmission oil is cooled with the engine coolant.

Some people go to great lengths to keep the tranny oil below 80 degrees - how it should be ideally - and you want more...

31st Jan 2019 9:26 pm

jules

Member Since: 13 Dec 2007
Location: The Wilds of Warwickshire
Posts: 4571

cheers for that - ill stop worrying Jules

1st Feb 2019 1:15 am

dorsetfreelander

Member Since: 20 Jul 2013
Location: Dorset
Posts: 4341

2014 Freelander 2 SD4 XS Auto Loire Blue

I was always under the impression that car cooling systems worked under pressure above 100C ie boiling point and that's why you should never remove the cap until it's cooled down otherwise you get a blast of steam and hot water all over you. 3 x FL1 2 manual + 1 auto
5 x FL2 4 manual + 1 auto
Now Discovery Sport P250 MHEV SE

1st Feb 2019 8:18 am

jules

Member Since: 13 Dec 2007
Location: The Wilds of Warwickshire
Posts: 4571

alex_pescaru wrote:
It's OK. Mine, during long cruises, both stay at about 82 degrees C.
And it's normal to have both the same temp as the transmission oil is cooled with the engine coolant.

Some people go to great lengths to keep the tranny oil below 80 degrees - how it should be ideally - and you want more...

I was checking the ATF temp because the manual says fill and measure ATF level at 60C. But as you say the ATF temp is in effect the same temp as the engine coolant due to transfer of heat via the ATF cooler. I found that even leaving the vehicle stationary from starting the engine the ATF temp rose rapidly in line with coolant temp. The 60C phase is rapidly passed after driving a mile or so.

So I would say if youve driven a few miles before topping up the autobox the ATF is likely to be a lot hotter than the required 60C. I dont know how much difference it makes to the volume of ATF needed when filling the autobox at nearer 80C though. Jules

1st Feb 2019 9:35 am

jules

Member Since: 13 Dec 2007
Location: The Wilds of Warwickshire
Posts: 4571

dorsetfreelander wrote:
I was always under the impression that car cooling systems worked under pressure above 100C ie boiling point and that's why you should never remove the cap until it's cooled down otherwise you get a blast of steam and hot water all over you.

Me too. Thats why I thought 80C seemed rather low.

However Ive been reassured by people with much more knowledge than me that 80C is fine for this type of modern cooling system. Old gits like me are more used to thermostats sitting directly on top of the cylinder head where temps are higher. Jules

Last edited by jules on 1st Feb 2019 11:54 am. Edited 1 time in total

1st Feb 2019 9:36 am

jules

Member Since: 13 Dec 2007
Location: The Wilds of Warwickshire
Posts: 4571

Re: ? over cooling ? thermostat stuck open

jules wrote:

FWIW The digital temp gauge remained bang in the middle (but we know its not a linear gauge and has a middle flat spot designed in to stop small changes in temp showing on the gauge and worrying customers)

IIRC someone on here did a mod to make the coolant temp gauge accurate and get rid of the middle "dead" zone - but I cant find it - anyone seen it ?

BMW stopped its customers from worrying about engine temp but removing the temp gauge completely. I discovered mine was routinely running at 110. Jules

1st Feb 2019 9:47 am

petero

Member Since: 27 Jul 2017
Location: Tamworth, Staffs
Posts: 49

2007 Freelander 2 TD4 HSE Manual Sumatra Black

Hi Jules, I think it was in this thread of Alex's: http://www.freel2.com/forum/topic19314.html
Regards, Peter

2nd Feb 2019 1:38 pm

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