Go Back   The 75 and ZT Owners Club Forums > The 75 and ZT Owners Club Forums > The 75 and ZT Owners Club General Forum
Register FAQ Image Gallery Members List Calendar Mark Forums Read
Notices

Reply
 
Thread Tools Display Modes
Old 26th December 2019, 15:40   #31
grivas
I really should get out more.......
 
grivas's Avatar
 
Rover 75 CDT Club Tourer

Join Date: Nov 2006
Location: Milky Way
Posts: 2,367
Thanks: 105
Thanked 513 Times in 382 Posts
Default

Quote:
Originally Posted by DMGRS View Post
The problem with our engines is that they're very thermally efficient - and with the heater on full blast you'll often see a less-than-optimal temperature, even on a long journey.

My last 75 had a new thermostat (OEM BMW) and that will happily sit at low 80s on a very cold morning, the same as my ZT-T with an inline item fitted.
With everything set up as it should be, that is to say correctly installed and functioning thermostat, and a well maintained Webasto heater, even in very cold conditions the car will be wonderfully warm inside in a matter of minutes.
grivas is offline   Reply With Quote
Old 26th December 2019, 17:12   #32
Mike Noc
This is my second home
 
Mike Noc's Avatar
 
Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4.

Join Date: Jul 2009
Location: Hampshire
Posts: 11,531
Thanks: 3,470
Thanked 3,119 Times in 2,247 Posts
Default

Yes as mentioned these are very thermally efficient engines and if the heat isn't there to be had then using different thermostats won't help.

Why do you think they fitted fuel burning heaters? They certainly aren't cheap.

This was BMW Development's answer when the question was asked in another thread, and it tells you all you need to know:

The M47R, as we called the engine, was different to the engine for the
320D. For the Rover (75) and Land Rover (Freelander) application we used the first common rail injection system.
I went back into my documentation and have spoken to the "older" colleagues in the development about the "cold" running engine.
We have never used different
Thermostat during the life span of the entire M47 engine (D and R), so we do not have different thermostats to choose from. We have introduced different thermostats for the late M57D.

Anyway, we are sure you cannot change the behaviour of the engine with a different thermostat. At the time when we introduced the direct injection diesel engine we had problems to get the engine to proper working temperature, because it was so efficient.

We remember that we had big problems to get enough heat for the passenger compartment heating, therefore we had additional heating.
Basically it would not help to get a different
thermostat, because the engine will not deliver more heat and therefore the operation temperature of the thermostat
does not matter.

I assume the cars are mostly driven in cities and will not get too much load on the engines. There is no other way to get the engine to hotter temperatures as to put load on them (faster driving or uphill driving!).
Sorry for this disappointing news , but if they want to play with thermostats, then I would recommend that they will take one out of the car and go to a spare part depot and have a look if they can find another one from a different car, which will fit. At that time, the supplier used mostly the same design for different car manufacturer.

BMW Group UK



Last edited by Mike Noc; 26th December 2019 at 17:16..
Mike Noc is offline   Reply With Quote
Old 26th December 2019, 18:38   #33
smudge.g
Gets stuck in
 
smudge.g's Avatar
 
75 Tourer CDTi Connie SE

Join Date: Jun 2017
Location: Keith, Banffshire
Posts: 686
Thanks: 431
Thanked 132 Times in 105 Posts
Default

If our diesel engines are so good at running cool, why does mine heat up very quickly (within 2 miles and needle at 9o'clock position) and gets so warm inside the cabin that i often have to open the windows? I am not able to monitor the temp using the 19/7 display as i cant seem to get to the 7 bit. After about 20-30mins, there is a noticeable cooling and the cabin doesnt get any warmer with the climate control untouched at 21 Deg. Is my thermostat playing up in my case??
__________________
My 75 Tourer CDTi was born Saturday, 21st June 2003 @ 09:50

My 75 was the 18,749th 75 Tourer to run off the production line, out of 27,407
It was the 195th 75 Tourer CDT Connoisseur SE (135) to be made out of 2,074
and the 1,789th 75 Tourer in Wedgewood Blue Metallic (code: JEL) to be made out of 1,871 Wedgewood Blue Metallic 75 Tourers
smudge.g is offline   Reply With Quote
Old 26th December 2019, 23:22   #34
trikey
Premium Trader
 
trikey's Avatar
 
Rover 75

Join Date: Nov 2010
Location: Devon
Posts: 33,710
Thanks: 8,837
Thanked 14,831 Times in 8,030 Posts
Default

Quote:
Originally Posted by smudge.g View Post
If our diesel engines are so good at running cool, why does mine heat up very quickly (within 2 miles and needle at 9o'clock position) and gets so warm inside the cabin that i often have to open the windows? I am not able to monitor the temp using the 19/7 display as i cant seem to get to the 7 bit. After about 20-30mins, there is a noticeable cooling and the cabin doesnt get any warmer with the climate control untouched at 21 Deg. Is my thermostat playing up in my case??


That does seem a very fast warmup time for a diesel, do try and access the obd display and take a reading as you may have a sticking stat (very unusual if you have though)
__________________
Lest we forget..
trikey is offline   Reply With Quote
Old 27th December 2019, 00:13   #35
clf
This is my second home
 
clf's Avatar
 
MG ZT CDTi

Join Date: Jan 2014
Location: carrick
Posts: 7,859
Thanks: 3,494
Thanked 2,657 Times in 1,973 Posts
Default

Quote:
Originally Posted by smudge.g View Post
If our diesel engines are so good at running cool, why does mine heat up very quickly (within 2 miles and needle at 9o'clock position) and gets so warm inside the cabin that i often have to open the windows? I am not able to monitor the temp using the 19/7 display as i cant seem to get to the 7 bit. After about 20-30mins, there is a noticeable cooling and the cabin doesnt get any warmer with the climate control untouched at 21 Deg. Is my thermostat playing up in my case??
I am guessing you are using the ATC set to 'auto'. When set to 'auto' the driver's side upper vents will begin to cool (guessing by mixing outside air to the warm) once the interior temp has reached its target (21 in your case). The idea being to keep the driver alert.

To verify this, 'feel' the air blowing at the driver's side lower, and the upper vents, then compare to the passenger side lower and upper vents. You should feel;

upper drivers side cool,
lower drivers side warm,
upper passenger side warm,
lower passenger side (as well as under seat to rear vents) warm.

You can override this, but I cannot recall exactly. Increasing the temperature target is one method, OR, if I recall, switching off the 'auto' and selecting the recirculating mode should do it.

-------------------

i would agree your temp rises very quickly, unless you have an operational parking heater. I am guessing you cannot get the 19/7 to work, as you may be selecting the 'on' instead of 'off', or holding the button in too long or too short. It took me a while to get it working.
__________________


It is not gloss primer .............. it is duct tape silver!
clf is offline   Reply With Quote
Old 27th December 2019, 10:18   #36
T-Cut
This is my second home
 
Rover75 and Mreg Corsa.

Join Date: Nov 2006
Location: Sumweer onat mote o'dust (Sagin)
Posts: 21,751
Thanks: 341
Thanked 3,660 Times in 2,924 Posts
Default

Quote:
Originally Posted by smudge.g View Post
I am not able to monitor the temp using the 19/7 display as i cant seem to get to the 7 bit.

If you follow the instructions as set out here: https://www.the75andztclub.co.uk/for...ad.php?t=55585


-and keep practising, you will soon succeed. The important thing when you're into section 19, is not to delay the first press when the screen shows 'log1-OFF'. You can let the 'Log1-ON' and 'Log1-OFF' cycle for as long as you like, but only press the button while 'Log1-OFF' is showing. Follow that press with regular half secon presses to switch through the numbers, 1-2-3-4-5-6-7 then stop. The Coolant Temperature will then pop on.

My bet is the numbers will tally with the heating you report. Remember though, that 'normal' on the gauge means it's 75C or more. You're really lokking for something nearer 90C.

TC

Last edited by T-Cut; 27th December 2019 at 10:23..
T-Cut is offline   Reply With Quote
Old 27th December 2019, 11:15   #37
Daveluck
Gets stuck in
 
75 saloon 2.0 diesel

Join Date: Feb 2016
Location: Panton, lugo, Galicia
Posts: 945
Thanks: 236
Thanked 192 Times in 143 Posts
Default

Quote:
Originally Posted by Mike Noc View Post
Yes as mentioned these are very thermally efficient engines and if the heat isn't there to be had then using different thermostats won't help.

Why do you think they fitted fuel burning heaters? They certainly aren't cheap.

This was BMW Development's answer when the question was asked in another thread, and it tells you all you need to know:

The M47R, as we called the engine, was different to the engine for the
320D. For the Rover (75) and Land Rover (Freelander) application we used the first common rail injection system.
I went back into my documentation and have spoken to the "older" colleagues in the development about the "cold" running engine.
We have never used different
Thermostat during the life span of the entire M47 engine (D and R), so we do not have different thermostats to choose from. We have introduced different thermostats for the late M57D.

Anyway, we are sure you cannot change the behaviour of the engine with a different thermostat. At the time when we introduced the direct injection diesel engine we had problems to get the engine to proper working temperature, because it was so efficient.

We remember that we had big problems to get enough heat for the passenger compartment heating, therefore we had additional heating.
Basically it would not help to get a different
thermostat, because the engine will not deliver more heat and therefore the operation temperature of the thermostat
does not matter.

I assume the cars are mostly driven in cities and will not get too much load on the engines. There is no other way to get the engine to hotter temperatures as to put load on them (faster driving or uphill driving!).
Sorry for this disappointing news , but if they want to play with thermostats, then I would recommend that they will take one out of the car and go to a spare part depot and have a look if they can find another one from a different car, which will fit. At that time, the supplier used mostly the same design for different car manufacturer.

BMW Group UK


But Mike, I thought the issue is that original thermostats themselves fail? Ie they stay open therefore continually cooling the engine?

I thought the inline simply replaces the work of the non functioning OEM thermostat. In other words the engine will produce and retain enough heat if you have a functioning thermostat.

My inline definitely works. I have more heat but it is still too low. Sits at 83c which I think is probably about 10c too low but that is considerably better than the 65c it was sitting at.
Daveluck is offline   Reply With Quote
Old 27th December 2019, 12:27   #38
T-Cut
This is my second home
 
Rover75 and Mreg Corsa.

Join Date: Nov 2006
Location: Sumweer onat mote o'dust (Sagin)
Posts: 21,751
Thanks: 341
Thanked 3,660 Times in 2,924 Posts
Default

Several members have formally reported running temperatures in the 90C area after fitting the recommended type of inline thermostat (not all thermostats are suitable). This clearly indicates the M47R engne will operate at optimal temperatures, without assistanc of a FBH, if the coolant flow is controlled more accurately. The OEM stats fail through a change in the melting characteristics of the wax in the capsule. This causes premature opening of the valve which causes over-cooling. When the OEM stat is cold, there is no flow through the valve.


TC

Last edited by T-Cut; 27th December 2019 at 12:29..
T-Cut is offline   Reply With Quote
Old 27th December 2019, 13:06   #39
kelvo
Gets stuck in
 
kelvo's Avatar
 
MG ZT 190 SE

Join Date: Oct 2017
Location: Chatham, Kent
Posts: 569
Thanks: 22
Thanked 163 Times in 135 Posts
Default

Quote:
Originally Posted by Daveluck View Post
But Mike, I thought the issue is that original thermostats themselves fail? Ie they stay open therefore continually cooling the engine?

I thought the inline simply replaces the work of the non functioning OEM thermostat. In other words the engine will produce and retain enough heat if you have a functioning thermostat.

My inline definitely works. I have more heat but it is still too low. Sits at 83c which I think is probably about 10c too low but that is considerably better than the 65c it was sitting at.
Not Rover or a diesel but I had a similar problem with my Volvo 740. Around town it was quite happy with the gauge at normal but on faster driving I tended to notice the temp gauge drop right down, but not always. Simple enough job to whip the elbow off and take the thermostat out and put in a saucepan of water, from what I discovered it was sticking open very slightly. Obviously around town it was able to warm up but on the motorway, the increased air flow cooled it down too much. New thermostat and was good as gold - thermonuclear heater restored.

Years ago with diesels you could probably blank off most of the radiator in cold weather and not cause any problems.
kelvo is offline   Reply With Quote
Old 27th December 2019, 17:00   #40
Mike Noc
This is my second home
 
Mike Noc's Avatar
 
Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4.

Join Date: Jul 2009
Location: Hampshire
Posts: 11,531
Thanks: 3,470
Thanked 3,119 Times in 2,247 Posts
Default

Quote:
Originally Posted by Daveluck View Post
But Mike, I thought the issue is that original thermostats themselves fail? Ie they stay open therefore continually cooling the engine?

I thought the inline simply replaces the work of the non functioning OEM thermostat. In other words the engine will produce and retain enough heat if you have a functioning thermostat.

My inline definitely works. I have more heat but it is still too low. Sits at 83c which I think is probably about 10c too low but that is considerably better than the 65c it was sitting at.

Yes they do Dave - they tend to start opening early, but the thread that post came was about fitting a different thermostat to increase the engine operating temperature, something that was looked at a few years ago.


It was bit like War and Peace: https://the75andztclub.co.uk/forum/s...ad.php?t=68468


I've nothing against in line stats but prefer to fit an original item as both the thermostat housings and O ring for the coolant rail can leak over time and will need replacing at some point.

Once you have done a few it isn't much of a job.

Last edited by Mike Noc; 27th December 2019 at 17:05..
Mike Noc is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 13:18.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd