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bogwert



Member Since: 02 Sep 2016
Location: Dundee
Posts: 194

Scotland 2003 Defender 90 Td5 CSW Zambezi Silver
Steady Drop in MPG - WHY!?
A question for the TD5 Experts of Defender 2?! Very Happy

Truck: 90 TD5 15P

Over the past 5 months I have noticed a continuous drop in our MPG?

The first year of owning the 90 she was pretty consistent at 28MPG - even with various driving styles - Long journeys / Short town trips - mid length up to the highlands... 28 .. there or there about.

Since Oct 17 its steadily declined up to the point of after filling up coming down to the Lake District we are at 20MPG.
She had a oil/ air / fuel filter service in Nov 16. A full Transfer box / Gearbox / Diffs / Engine / All Filters change in Dec 17.

I've looked along the fuel lines, that i can get to and cant find any wet / leaky areas. All oil levels are correct...

Any suggestions? Question


Click image to enlarge
 Chris

2014 Discovery 4 TDV6 HSE
2003 Defender 90 TD5 CSW


Last edited by bogwert on 19th Mar 2018 2:00pm. Edited 1 time in total
Post #694617 19th Mar 2018 12:12pm
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Supacat



Member Since: 16 Oct 2012
Location: West Yorkshire
Posts: 11018

United Kingdom 2013 Defender 110 Puma 2.2 XS DCPU Keswick Green
Jack up vehicle and check for any binding/ drag at wheels, props & transfer brake.

Go for a run, apply no brakes when stopping & jump out and check for any unusual heat for same places.

If you can rule out the simple things then its on to other less obvious ones.
Post #694634 19th Mar 2018 1:52pm
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gazman



Member Since: 17 Aug 2015
Location: Liverpool
Posts: 652

United Kingdom 2003 Defender 90 Td5 HT Alpine White
are you simply driving it harder? or is it the cold? are your tyre pressures correct?

As above check brakes etc for binding.

Mine dropped off too, it was a slight boost leak and I was driving harder to drive the same speed. 2014 - current ..... 2003 defender td5 90 (my car)
2009 - current .... 2005 zx10r
Post #694637 19th Mar 2018 1:59pm
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bogwert



Member Since: 02 Sep 2016
Location: Dundee
Posts: 194

Scotland 2003 Defender 90 Td5 CSW Zambezi Silver
I did change the rear pads a while back but I would have expected them to bed in by now.

I wouldn't say I'm driving harder, and yes I currently is pretty cold, although pretty standard for Scotland.. and its not been ice cold since October... I hope!

Tyre pressures, I'm pretty good at keeping them level and correct - but again a good shout, new MT's on there 3 weeks back so I'll endeavor to keep them correct.

a boost leak? Would this come from the input / output on the turbo? Now you mention that there is a slight dint in on the in hose by the radiator!? might have started to tear through?! Confused Chris

2014 Discovery 4 TDV6 HSE
2003 Defender 90 TD5 CSW
Post #694647 19th Mar 2018 2:19pm
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zsd-puma



Member Since: 09 Aug 2016
Location: Kent
Posts: 2720

United Kingdom 2010 Defender 110 Puma 2.4 USW Santorini Black
Weather getting colder. That graph pretty much follows the temperature drop through winter, including the latest cold snap.

Diesels take longer to warm up than petrol engines, and don't reach full efficiency until warm.

You'll also be running things like the heater fan, as well as heated screens and seats if fitted. You'll be using your lights more too. All that drains the battery which the alternator has to top back up which puts more load on the engine.

Try putting a bit of card board in front of the radiator and see if your fuel economy improves.
Post #694653 19th Mar 2018 2:32pm
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grafty99



Member Since: 15 Aug 2012
Location: North Devon
Posts: 4786

United Kingdom 2002 Defender 90 Td5 HT Caledonian Blue
Would be worth having it plugged in and having a look at the injector trim. They may be getting worn and the ecu has reached its trim limit 2002 90 Td5 Station Wagon
1990 Vogue SE
Triumph Tiger Explorer 1200
Td5 90 Thread http://www.defender2.net/forum/topic50767.html
Tdi 110 Thread https://www.defender2.net/forum/topic69562.html
RRC Thread http://www.defender2.net/forum/topic54492.html
Instagram http://www.instagram.com/george_grafton
Post #694656 19th Mar 2018 2:43pm
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bogwert



Member Since: 02 Sep 2016
Location: Dundee
Posts: 194

Scotland 2003 Defender 90 Td5 CSW Zambezi Silver
Hummmm... Ok, so see if it improves over the next few months... if spring does come! Laughing

If not, start plugging things in!! Smile Chris

2014 Discovery 4 TDV6 HSE
2003 Defender 90 TD5 CSW
Post #694661 19th Mar 2018 3:07pm
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Muddybigdog



Member Since: 11 Apr 2014
Location: Suffolk
Posts: 1020

United Kingdom 2007 Defender 90 Puma 2.4 XS CSW Zambezi Silver
Defrosting, demisting, fan on longer/higher, oil in engine thicker, oil in gearbox/diffs thicker, lights on more often, plus diesel reduces 1-2% in a colder climate, hence uses more fuel Jumped ship to reliability - Mitsubishi L200
Puma 90 XS - Sold
D3 - 2.7 S x2 (both Sold)
Freelander 2 HSE - Sold
Freelander 1 - Sold
Disco 2 - Sold
Post #694778 19th Mar 2018 9:42pm
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Hufflepuff



Member Since: 25 Oct 2014
Location: Hampshire
Posts: 727

England 2005 Defender 90 Td5 XS CSW Tonga Green
You shouldn't be getting 20 mpg on a motorway run though in a 90, unless you were giving it full beans all the way down? The worst I ever achieved was 24mpg in a fully loaded 90 coming up through France at a steady 130kph. Normally in the UK I'm at around 28mpg the motorway at a steady 65-70mph. 2005 Td5 90 XS
1989 V8 110 CSW
Post #694800 19th Mar 2018 11:06pm
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geobloke



Member Since: 06 Nov 2012
Location: Nottinghamshire
Posts: 4410

United Kingdom 
grafty99 wrote:
Would be worth having it plugged in and having a look at the injector trim. They may be getting worn and the ecu has reached its trim limit


Hi Grafty. What is the trim limit?
Post #694825 20th Mar 2018 6:54am
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bogwert



Member Since: 02 Sep 2016
Location: Dundee
Posts: 194

Scotland 2003 Defender 90 Td5 CSW Zambezi Silver
gazman wrote:
are you simply driving it harder? or is it the cold? are your tyre pressures correct?

As above check brakes etc for binding.

Mine dropped off too, it was a slight boost leak and I was driving harder to drive the same speed.


Had a wee look at what was the 'dint' in the pipe! its now a small tear! Shocked

Please excuse the mud, its from this weekend's green laneing, Friday afternoon is bath day!


Click image to enlarge



Click image to enlarge



Click image to enlarge


Anyone know the part number for a replacement pipe?


I'm thinking it might be a mixture of the 2 cold weather and leaky pipe meaning the engine is working harder? Chris

2014 Discovery 4 TDV6 HSE
2003 Defender 90 TD5 CSW
Post #694851 20th Mar 2018 8:31am
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Supacat



Member Since: 16 Oct 2012
Location: West Yorkshire
Posts: 11018

United Kingdom 2013 Defender 110 Puma 2.2 XS DCPU Keswick Green
It's good you may have got to the failure, it is what looks like a the bolt head just below that's caused the damage?

Proves monitoring the fuel economy religiously can be used as part of a maintenance programme.
Post #694878 20th Mar 2018 9:49am
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bogwert



Member Since: 02 Sep 2016
Location: Dundee
Posts: 194

Scotland 2003 Defender 90 Td5 CSW Zambezi Silver
I think its defiantly a contributor!!

Now the simple 10 minute job to change the pipe.... AH!

Any shouts on the part number? cant find it on LRCAT! Chris

2014 Discovery 4 TDV6 HSE
2003 Defender 90 TD5 CSW
Post #694891 20th Mar 2018 10:23am
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rallysteve



Member Since: 10 Feb 2014
Location: Cumbria
Posts: 2237

United Kingdom 2002 Defender 110 Td5 DCPU Keswick Green
Looks like PNH102090 to me (cooling and heating > cooling > intercooler)

Steve 02' 110 TD5 Double Cab Rebuild Thread
Post #694905 20th Mar 2018 11:16am
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bogwert



Member Since: 02 Sep 2016
Location: Dundee
Posts: 194

Scotland 2003 Defender 90 Td5 CSW Zambezi Silver
Ah! Found a label hiding further down! PNH 102071! Thumbs Up

Guess I might as well just replace the whole length! Neutral Chris

2014 Discovery 4 TDV6 HSE
2003 Defender 90 TD5 CSW
Post #694906 20th Mar 2018 11:28am
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