Diesel Running tempreture.

thundercat · 4th November 2016, 06:32

How important is engine temperature to the efficient running of the Diesel Engine, the temp on mine is not hardly moving even after a 20 mile run

Mickyboy · 4th November 2016, 06:36

Temp is very important for mpg/correct heating in the cabin and general engine wear, I would suggest a inline thermostat fitted in the top hose 88 degree is the correct temp, I fit 89 degree Ines in my cars.
Hope that helps mate

iandux · 4th November 2016, 06:36

Chances are that the thermostat has failed.

Search 'Inline thermostat mod' on here for the easy solution

http://www.the75andztclub.co.uk/foru...ad.php?t=74451

T-Cut · 4th November 2016, 09:44

There are several threads from members who report up to 10% improvement in MPG after getting the engine to run around 90C.

The temperature gauge will tell you very little. The so-called 'normal' point (at 9 o'clock on the face) means anything from 75C to 115C. The only way to know what it's actually running at is to use the trip screen Diagnostic Mode or fit a proper temperature gauge.

Diagnostic Mode: http://www.the75andztclub.co.uk/foru...ad.php?t=55585

TC

thundercat · 4th November 2016, 11:00

Quote:

Originally Posted by T-Cut

There are several threads from members who report up to 10% improvement in MPG after getting the engine to run around 90C.

The temperature gauge will tell you very little. The so-called 'normal' point (at 9 o'clock on the face) means anything from 75C to 115C. The only way to know what it's actually running at is to use the trip screen Diagnostic Mode or fit a proper temperature gauge.

Diagnostic Mode: http://www.the75andztclub.co.uk/foru...ad.php?t=55585

TC

Thanks for the info, so that's 19/7 then

Frank Incensed · 4th November 2016, 11:31

Hi

I've had my car 6 years. When I got it, the coolant temperature would get to a maximum of 88C.

A couple of years ago, the thermostat failed - the coolant temperature getting to no higher than 70C - and I put in a top hose thermostat (88C). The maximum indicated temperature would then fluctuate between 86C and 91C as the thermostat opened and closed.

This year, the seals to the lower thermostat started leaking, so I had to have it replaced anyway - and the car now has two working thermostats! At a constant engine load, the maximum indicated temperature now remains steady at 89C.

With, or without a working thermostat, I have experienced NO change in mpg that couldn't be otherwise explained away, either by slightly different ambient conditions, or different journey types, for that particular tank of diesel.

So don't be disappointed if your car doesn't suddenly start returning 60 mpg with a new thermostat!

Engine wear might be a good reason for changing the thermostat, but (unless you you have a fuel burning heater) the onset of winter certainly is. Without a working thermostat my car needs a journey of about 7 miles before the heater makes the cabin warm. With a working thermostat it takes 1 to 2 miles from starting.

BTW - in the 6 years of ownership, the only thing that has significantly affected mpg is a failed MAF when it dropped by about 1/3 and the car ran on 3 cylinders when cold. But other people will tell you their car runs better without a MAF and gives incredible mpg.
I understand, if you normally do longish journeys (which I don't), a 160 re-map might be beneficial by 2 or 3 mpg.

HTH

4th November 2016, 06:32	#1
thundercat Posted a thing or two Rover 75 Club SE Join Date: Jul 2012 Location: saxmundham Posts: 1,438 Thanks: 289 Thanked 173 Times in 121 Posts	Diesel Running tempreture. How important is engine temperature to the efficient running of the Diesel Engine, the temp on mine is not hardly moving even after a 20 mile run

4th November 2016, 06:36	#2
Mickyboy SERVICING AND DEALER DIAGNOSTICS MG ZT CDTI 135 + & MGZT CDTI AUTO 160 & ROVER 75 TOURER CDTI 160 TROPHY YELLOW Join Date: Aug 2013 Location: Hernebay Posts: 4,331 Thanks: 818 Thanked 2,414 Times in 1,141 Posts	Temp is very important for mpg/correct heating in the cabin and general engine wear, I would suggest a inline thermostat fitted in the top hose 88 degree is the correct temp, I fit 89 degree Ines in my cars. Hope that helps mate __________________ [SIGPIC][/SIGPIC] T4 Owner Jobs done : new UBP, Spy hole mod, Rear hub(wheel bearing),plenum cleaned and emptied, Inline thermostat fitted,Full service, In car Digital tv/DVD Bluetooth Satnav etc, Replaced UBP, Restored headlights,Fixed airbag connection.replaced HP pump,replaced rear light seals,changed intercooler O rings. Jobs to do: ,replace drivers lock,.[/SIZE]

4th November 2016, 06:36	#3
iandux Loves to post At last....75 Facelift Connie Join Date: Aug 2013 Location: Longridge Posts: 443 Thanks: 199 Thanked 117 Times in 70 Posts	Chances are that the thermostat has failed. Search 'Inline thermostat mod' on here for the easy solution http://www.the75andztclub.co.uk/foru...ad.php?t=74451 __________________ A man is not a failure if he falls.....only if he refuses to get up again. This vehicle was the 96,129th 75 to run off the production line, out of 112,381 This vehicle was the 2,123rd 75 CDT Connoisseur SE (135) to be made out of 4,744 This vehicle was the 394th 75 in Firefrost Red (code: CEV) to be made out of 2,089 Firefrost Red 75s Last edited by iandux; 4th November 2016 at 06:42..

4th November 2016, 09:44	#4
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,752 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	There are several threads from members who report up to 10% improvement in MPG after getting the engine to run around 90C. The temperature gauge will tell you very little. The so-called 'normal' point (at 9 o'clock on the face) means anything from 75C to 115C. The only way to know what it's actually running at is to use the trip screen Diagnostic Mode or fit a proper temperature gauge. Diagnostic Mode: http://www.the75andztclub.co.uk/foru...ad.php?t=55585 TC Last edited by T-Cut; 4th November 2016 at 09:48..

4th November 2016, 11:31	#6
Frank Incensed Ex 75 Owner 75 Tourerless Join Date: Jul 2010 Location: Manchester Posts: 2,147 Thanks: 60 Thanked 156 Times in 93 Posts	Hi I've had my car 6 years. When I got it, the coolant temperature would get to a maximum of 88C. A couple of years ago, the thermostat failed - the coolant temperature getting to no higher than 70C - and I put in a top hose thermostat (88C). The maximum indicated temperature would then fluctuate between 86C and 91C as the thermostat opened and closed. This year, the seals to the lower thermostat started leaking, so I had to have it replaced anyway - and the car now has two working thermostats! At a constant engine load, the maximum indicated temperature now remains steady at 89C. With, or without a working thermostat, I have experienced NO change in mpg that couldn't be otherwise explained away, either by slightly different ambient conditions, or different journey types, for that particular tank of diesel. So don't be disappointed if your car doesn't suddenly start returning 60 mpg with a new thermostat! Engine wear might be a good reason for changing the thermostat, but (unless you you have a fuel burning heater) the onset of winter certainly is. Without a working thermostat my car needs a journey of about 7 miles before the heater makes the cabin warm. With a working thermostat it takes 1 to 2 miles from starting. BTW - in the 6 years of ownership, the only thing that has significantly affected mpg is a failed MAF when it dropped by about 1/3 and the car ran on 3 cylinders when cold. But other people will tell you their car runs better without a MAF and gives incredible mpg. I understand, if you normally do longish journeys (which I don't), a 160 re-map might be beneficial by 2 or 3 mpg. HTH __________________ Beyoncé's Green Light Used More Rubber 355188 of 355194 Last edited by Frank Incensed; 4th November 2016 at 11:42..