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 16th September 2020, 20:04   #11
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 kelvo View Post
My understanding has been that diesel engines inherently run cold because they are more efficient and hence generate less 'waste' heat which is why they always take that much longer to warm up, particularly in cold weather.
That's perfectly true. The high compression ratio of diesel engines makes for greater thermal efficiency. But, the 'waste' you mention is useful heat absorbed by the block because it's at a low temperature. A hotter engine runs more efficiently because a greater proportion of the total energy produced by combustion is used to do work. If you could get the block to a higher temperature in a short time, the fuel efficiency would increase. That's been reported by members after fitting the in-line stat system. But it's about as far as you can go without lagging the engine and such. MGR fitted the FBH to help provide provide a hotter block at startup. Of course, the FBH doesn't improve overall mpg because you're burning diesel to warm the engine without driving the car.

See: https://en.wikipedia.org/wiki/Heat_engine


TC

Last edited by T-Cut; 16th September 2020 at 20:09..
T-Cut is offline   Reply With Quote
Old 21st September 2020, 18:50   #12
75driver
Posted a thing or two
 
75driver's Avatar
 
Rover 75 saloon, manual. Rover 75 Tourer, Auto.

Join Date: Jan 2013
Location: Newry
Posts: 1,775
Thanks: 574
Thanked 443 Times in 371 Posts
Default

Well, I tried re-bleeding at the the weekend, but still no change.
On a 100 mile run this morning, it was easy enough to observe the opening pattern.
Stat appeared to open when the temp readout on obd was about 93, but if going up a hill at this point, it would rise to 95/96/97
Similarly, if it was at 91 on a flat road or down hill for about a minute or so with no engine load, stat would open at 91.
I think it’s just a very slow opening stat.
Although it may be good for winter, I’m not sure I’d like it like this long term, so will probably try a different stat at the weekend, or possibly drill a small bleed hole.


Sent from my iPad using Tapatalk
__________________
2006 75 Contemporary SE diesel manual (#1)

2003 75T Connoisseur SE diesel auto (For Comfort)
2005 75 Connoisseur SE diesel auto (Marmite duotone )
2006 75 Connoisseur SE diesel auto (The last one?)

2009 E220 (For a change)
2018 L200 (For Big & Heavy Things)
1976 W114 250 Manual (For Sundays)
75driver is offline   Reply With Quote
Old 21st September 2020, 19:38   #13
rovertone
Gets stuck in
 
Rover 75 Conne SE Auto CDTi

Join Date: Nov 2012
Location: Redditch
Posts: 665
Thanks: 185
Thanked 135 Times in 109 Posts
Default

I had a problem when I bought my car with cool running so changed to a standard stat,( i didn't use top hose mod because I tow) after which the temp stayed fairly static at 89/91c and might rise to 93/95 on long climbs. I am talking here about long distance runs through Spain etc.

What I have found is that the engine gets hot very quickly when given some work to do i.e towing where i have found on gradients in the uk temps would quickly rise to high 90's and abroad would get near to overheating and has overheated on gradients at high ambient temps.

From my experience I wouldn't trust my car again towing abroad but due to health issues am probably not going to tow any longer so it matters not. I have a hunch that with the engine fitted transversely with the undertray on there is barely any space for air flow around the engine.

I am not wanting to introduce 'towing' into the thread to divert from the original question but to I have proved that these engines can get very hot. In normal driving if the temp reached say 98/99 the temp gauge would stay 'normal' so most drivers would not be aware. As a thought presumably the original stat is still in place, could it be partially closed restricting flow to the inline stat and causing fluctuation of temps?
__________________
2003 Mk 1 Connie SE CDTi Auto Monogram Mirage 2/Sandstone Leather
511th CDTi out of 4744 produced
9th in Mirage 2 out of 17 produced
Also 2004 Rover 25 SXi CVT, 1999 Megane Cabriolet and still missing my 800 Fastback
.
rovertone is offline   Reply With Quote
Old 21st September 2020, 22:45   #14
Arctic
Give to Learn
 
Arctic's Avatar
 
Freelander 2

Join Date: Aug 2010
Location: West Midlands
Posts: 18,651
Thanks: 1,155
Thanked 6,407 Times in 3,874 Posts
Default

Quote:
Quote:
Originally Posted by 75driver View Post
Well, I tried re-bleeding at the the weekend, but still no change.
On a 100 mile run this morning, it was easy enough to observe the opening pattern.
Stat appeared to open when the temp readout on obd was about 93, but if going up a hill at this point, it would rise to 95/96/97
Similarly, if it was at 91 on a flat road or down hill for about a minute or so with no engine load, stat would open at 91.
I think it’s just a very slow opening stat.
Although it may be good for winter, I’m not sure I’d like it like this long term, so will probably try a different stat at the weekend, or possibly drill a small bleed hole.


Sent from my iPad using Tapatalk
HI Sean.
Personally i would run with that stat for at least a few weeks if not longer with the colder weather coming in, we have all tried to get our diesels to run at least 90-92 before opening and then hopefully maintain 87- 89 what stat did you use or have i missed a part that you have already stated which stat you inserted.

As long as the level in the tank is ok you are getting hot air circulation what's not to like, make sure the header tank cap O-rings are good Viton ones and enjoy the warmth over the winter months
__________________
Arctic
Givology Learn to Give
Everything is Achievable

ad altiora tendo.

Check out our Nano meet dates
http://www.midlandsnanomeets.co.uk/

http://www.the75andztclub.co.uk/index.php?thepage=howto

" You do the work , we supply the expertise "

Last edited by Arctic; 22nd September 2020 at 09:49.. Reason: rectification
Arctic is offline   Reply With Quote
Old 21st September 2020, 23:29   #15
75driver
Posted a thing or two
 
75driver's Avatar
 
Rover 75 saloon, manual. Rover 75 Tourer, Auto.

Join Date: Jan 2013
Location: Newry
Posts: 1,775
Thanks: 574
Thanked 443 Times in 371 Posts
Default

Hi Steve,
Stat is from local motor factors “motaquip” FTS104.88 / VTK169, that fits into a specialist components housing, within the top hose.
Level in the tank is fine and remains constant, slightly above the full markers at the bottom of the tank, and am getting hot air thru the vents.
Header tank cap o rings are good, as I replaced them with new Viton ones.
I have suspicions that, either,
A) the stat within the specialist components housing may be too good, and that zero leak through, in combination with original stat, just doesn’t let water through quick enough, when needed too, ( as hinted to by Rover tone in post above).

B) it’s just a slow opening stat. A replacement one from dmgrs has been ordered to check next week.

I’ve had similar experiences with the specialist component stat before, on the tourer I think. In the end I just drilled a small hole thru the stat, which gave more steady state temperatures (ie more like 87 /88 rather than 96/97 dropping to 82 on opening of stat.
Ok, I know it’s likely to take longer for initial warm up in winter, but it may prove to be a safer approach.

Anyhow, I’ll see if I can be tempted to do the 19....7... thing on the obd for the rest of the week to monitor temps, but wouldn’t like to rely on having to do it long term.😬. That’s one of the reasons I have a diesel.🤭🤭🤭


Sent from my iPad using Tapatalk
__________________
2006 75 Contemporary SE diesel manual (#1)

2003 75T Connoisseur SE diesel auto (For Comfort)
2005 75 Connoisseur SE diesel auto (Marmite duotone )
2006 75 Connoisseur SE diesel auto (The last one?)

2009 E220 (For a change)
2018 L200 (For Big & Heavy Things)
1976 W114 250 Manual (For Sundays)
75driver is offline   Reply With Quote
Old 22nd September 2020, 09:29   #16
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

Providing the radiator fan operates as it should (on at 100C), what is there to worry about? The diesel is robust enough to run all day in the mid to upper 90s. Many shivering owners would welcome it.


TC
T-Cut is offline   Reply With Quote
Old 22nd September 2020, 21:31   #17
Arctic
Give to Learn
 
Arctic's Avatar
 
Freelander 2

Join Date: Aug 2010
Location: West Midlands
Posts: 18,651
Thanks: 1,155
Thanked 6,407 Times in 3,874 Posts
Default

I have been fitting the inline stat since 2011 using only the Gates stat my preferred stat to use.

1

2

3

4

5

6

I know the specialist components housing requires a different stat.

7
__________________
Arctic
Givology Learn to Give
Everything is Achievable

ad altiora tendo.

Check out our Nano meet dates
http://www.midlandsnanomeets.co.uk/

http://www.the75andztclub.co.uk/index.php?thepage=howto

" You do the work , we supply the expertise "
Arctic is offline   Reply With Quote
Old 3rd October 2020, 18:53   #18
75driver
Posted a thing or two
 
75driver's Avatar
 
Rover 75 saloon, manual. Rover 75 Tourer, Auto.

Join Date: Jan 2013
Location: Newry
Posts: 1,775
Thanks: 574
Thanked 443 Times in 371 Posts
Default

Just to conclude the thread, I monitored the temperature via obd for the last 2 weeks, on several 100 mile journeys.
Conclusion: the motoquip stat was unreliable, sometimes opening at 87, sometimes at 93, sometimes at 97. The rate of temperature increase also varied inconsistently, which, tbh, just made me think the stat wasn’t operating correctly.

Installed a (first line) 88 deg stat (from DMGRS) today, and normality is restored.
New stat opens at 88/89, dropping to 84, and does it consistently, which is more reassuring.

Old stat is free to anyone who wants to try it out, but for clarity, it is not the “in hose” stat, but one that sits within a housing manufactured by specialist components.


Sent from my iPhone using Tapatalk
__________________
2006 75 Contemporary SE diesel manual (#1)

2003 75T Connoisseur SE diesel auto (For Comfort)
2005 75 Connoisseur SE diesel auto (Marmite duotone )
2006 75 Connoisseur SE diesel auto (The last one?)

2009 E220 (For a change)
2018 L200 (For Big & Heavy Things)
1976 W114 250 Manual (For Sundays)
75driver is offline   Reply With Quote
Old 4th October 2020, 12:43   #19
Avulon
This is my second home
 
1.8t Tourer

Join Date: Oct 2011
Location: Tanelorn
Posts: 4,830
Thanks: 956
Thanked 1,148 Times in 916 Posts
Default

Quote:
Originally Posted by 75driver View Post
Just to conclude the thread, I monitored the temperature via obd for the last 2 weeks, on several 100 mile journeys.
Conclusion: the motoquip stat was unreliable, sometimes opening at 87, sometimes at 93, sometimes at 97. The rate of temperature increase also varied inconsistently, which, tbh, just made me think the stat wasn’t operating correctly.

Installed a (first line) 88 deg stat (from DMGRS) today, and normality is restored.
New stat opens at 88/89, dropping to 84, and does it consistently, which is more reassuring.

Old stat is free to anyone who wants to try it out, but for clarity, it is not the “in hose” stat, but one that sits within a housing manufactured by specialist components.


Sent from my iPhone using Tapatalk

IIRC there was mention many years ago about whether or not a top hose stat (whether in housing or just top pipe) needed a small bypass / bleed hole or not. With no bleed hole and if it's further along the pipe then there's no flow at all to help carry the heat to the stat bulb. The closer the stat is to the block the less of an issue this might be. (just my tuppence).
__________________
Need a T4 ?: T4 Owners Map thanks to Stevestrat ( use at your own risk)

Where?:
https://en.wikipedia.org/wiki/Tanelorn
Mods/Retrofits:

PCV vortex 'filter'; bluetooth; inline thermostat; reversing sensors; plenum spyhole ; headlamp washers ; Diy mp3 player replacing CD multichanger; FBH with remote; Headlamp washers; black/chrome front grille, rear blind; Xenon projectors
To do:
puddle lights; 2 Din cd/nav to fit; boot release button
Avulon is offline   Reply With Quote
Old 4th October 2020, 14:50   #20
75driver
Posted a thing or two
 
75driver's Avatar
 
Rover 75 saloon, manual. Rover 75 Tourer, Auto.

Join Date: Jan 2013
Location: Newry
Posts: 1,775
Thanks: 574
Thanked 443 Times in 371 Posts
Default

Quote:
Originally Posted by Avulon View Post
IIRC there was mention many years ago about whether or not a top hose stat (whether in housing or just top pipe) needed a small bypass / bleed hole or not. With no bleed hole and if it's further along the pipe then there's no flow at all to help carry the heat to the stat bulb. The closer the stat is to the block the less of an issue this might be. (just my tuppence).

I can’t say I disagree, and alluded to this some time ago on a different thread.
However, I couldn’t see any bleed hole on the new first line stat, which now functions as you would expect. Maybe it just doesn’t seal as tightly? Who knows?


Sent from my iPhone using Tapatalk
__________________
2006 75 Contemporary SE diesel manual (#1)

2003 75T Connoisseur SE diesel auto (For Comfort)
2005 75 Connoisseur SE diesel auto (Marmite duotone )
2006 75 Connoisseur SE diesel auto (The last one?)

2009 E220 (For a change)
2018 L200 (For Big & Heavy Things)
1976 W114 250 Manual (For Sundays)
75driver 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 22:15.


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