Advertise on DISCO3.CO.UK
Forum · Gallery · Wiki · Shop · Sponsors
DISCO3.CO.UK > Technical (D3)

Fuel consumption doubled overnight, need help
Post Reply  Down to end
Page 2 of 2 <12
jmccmick
 


Member Since: 21 Nov 2021
Location: BC
Posts: 5

Canada 2007 LR3 4.0 V6 Petrol SE Auto Buckingham BlueLR3
update

Well, the shop took a look at it at the end of the day.
The engine code that came up as I rolled into the lot was O2 sensors; wonderful news as a simple straightforward fix, and 60k since last time I changed them so im more than happy for all 4 to get switched out now.
Something in the front diff is making a rubbing noise, but they haven't dissembled it yet to determine what is rubbing what.
They are suspicious the timing is off and is the cause of loss of top-end power, and will get cover off to check tomorrow.

I was a little worried it would be a diff or transmission issue, though im at a bit of a loss to explain either doubling the fuel consumption. Maybe its the sum of a little bit of all of the above.
Hopefully something definitive tomorrow
  
Post #226378324th Nov 2021 1:24 am
View user's profile Send private message View poster's gallery Reply with quote
Globetrotter448
 


Member Since: 21 Mar 2017
Location: Londonderry NSW
Posts: 1772

Australia 2007 Discovery 3 4.0 V6 Petrol SE Auto Java BlackDiscovery 3

If it was the O2 sensors making it run rich then surely you would see black smoke. But on these vehicles you will never know. Keep the old sensors.
  
Post #226378424th Nov 2021 2:25 am
View user's profile Send private message View poster's gallery Reply with quote
M3DPO
 


Member Since: 22 Sep 2010
Location: Notts.
Posts: 8044

England 2014 Discovery 4 3.0 SDV6 HSE Lux Auto Corris GreyDiscovery 4

As your title says “doubled overnight”, is it still doing it or has it returned to normal? - if it was a one off check the filler cap is locking not unknown for a scrote to symphony a few gallons off in the night, they have even been known to drill a hole in the tank particularly on lorries.
 It can when others can't,
It will when others won't,
It goes where others don't. 
 
Post #226378724th Nov 2021 6:26 am
View user's profile Send private message View poster's gallery Reply with quote
Breg90
 


Member Since: 04 Feb 2017
Location: Falkirk
Posts: 347

United Kingdom 2008 Discovery 3 TDV6 XS Manual Java BlackDiscovery 3

Front diff will likely be a carrier bearing failing on the small side. Drain the oil out for the diff and look for particles. Mine was the rear diff, even though I could have sworn it was the front.

You can rebuild them with new bearings for a reasonable amount of ££/$$. But not your average mechanic job. A refurb diff might be the way forward.
 Series one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits 
 
Post #226379824th Nov 2021 9:09 am
View user's profile Send private message View poster's gallery Reply with quote
jmccmick
 


Member Since: 21 Nov 2021
Location: BC
Posts: 5

Canada 2007 LR3 4.0 V6 Petrol SE Auto Buckingham BlueLR3

The rear diff had a dribble I noticed when I went looking for other causes of increased resistance the front had looked clean at the time (I thought).
I swapped out the oil and removed the unfortunate looking collection of metal particles from the magnet.
I was concerned for the rear diff but had though the front was fine until it started making noises the morning I got it into the shop.
I might try to take this opportunity to put two ARB loaded diffs underneath...
  
Post #226392425th Nov 2021 3:38 am
View user's profile Send private message View poster's gallery Reply with quote
jmccmick
 


Member Since: 21 Nov 2021
Location: BC
Posts: 5

Canada 2007 LR3 4.0 V6 Petrol SE Auto Buckingham BlueLR3
delayed update

With the holidays it took until early January for it to be repaired, then my dad to fly back to get it. It ended up being the catalytic converters failing and increasing back pressure on the engine, which I had not heard of happening before. Used cats from a donor vehicle replaced mine. The front diff was replaced as well from a donor vehicle with similar mileage as the bearings had cooked and left some debris floating about for who-knows how many km. Rear diff seals replaced but the metal bits were all in good shape.
At last the vehicle made it to the new house, but the fuel economy had improved to 15km/L driving across the province, then worsened to 20km/L after arriving. And now, finally, theres a simple good old fashioned piston rusted solid on the rear left ( I had replaced the rear right in the early fall). The new pads and caliper are here and I will be replacing this weekend, and hopefully that will be the end of this saga.
  
Post #227841911th Feb 2022 5:51 pm
View user's profile Send private message View poster's gallery Reply with quote
Gary_P
 


Member Since: 03 May 2016
Location: Kent
Posts: 1506

Ukraine 2016 Discovery 4 3.0 SDV6 HSE Auto Corris GreyDiscovery 4

Are you sure about those figures in that last post? 20KM/L is an improvement on 15km/L and by my calcs 15km is 10 miles - ish which is very good going on a litre of fuel !
Presume you mean 15L/100Km ??
Good luck getting it sorted. Sounds like you've been through it. Really good to get an update post.
 Gary
-------------------------------------------

Discovery 4 HSE 2016MY 
 
Post #227845111th Feb 2022 9:18 pm
View user's profile Send private message View poster's gallery Reply with quote
Yankee_Rover
 


Member Since: 02 Jun 2021
Location: Seattle
Posts: 183

United States 2008 LR3 4.4 V8 HSE Lux Auto Zermatt SilverLR3

Presume they meant 15L/100km and 20L/100km.


Excess fuel in a petrol engine produces white smoke (not black). In the winter it can easily be confused with water vapor burning off, but it is easily distinguishable because it will reek of gasoline. I hypothesize that the O2 sensor gave out causing engine to run rich, which will kill a catalytic convertor if left unchecked. The back pressure thing doesn’t make sense to me, though I don’t know their failure mechanisms well.

Also possible the cat just gave out and the O2 sensor correctly reported the failure with the CEL. Seems odd to run rich for so long a trip with no codes. Running live data checks could have shown the rich condition via fuel trim. But the cat was probably toast by then anyway.

Hope you are fixed after the caliper and rotor!
 2008 LR3 HSE, 4.4L V8  
Post #227845812th Feb 2022 12:07 am
View user's profile Send private message View poster's gallery Post Reply
Display posts from the last:  
Post Reply Back to top
Page 2 of 2 <12
Jump to:  
Previous Topic | Next Topic >


Posting Rules
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum



DISCO3.CO.UK Copyright © 2004-2024 Futuranet Ltd & Martin Lewis
DISCO3.CO.UK RSS Feed - All Forums

DISCO3.CO.UK is independent and not affiliated to Land Rover.
Switch to Mobile Site