Please help - poor diesel economy

[goldey]

Gents

We have had our 98 300tdi auto discovery now for a bit over a month. In that time we've done about 900k's and used 130 litres (ie 14.5l/100k's). This seems pretty thirsty for a diesel. I did a search and most of the diesel guys are getting around the 10-11l/100k's.

In the 900k's we did about 70ks of high range sand and about 5k's of low range bush driving. The rest has been around town driving. We've got 245/75R16 muddies and a snorkel.

Since buying the car I have replaced the air and oil filters and put new engine oil in. I have not replaced the fuel filter or any of the other fluids (ie gearbox, diffs transfer etc) yet or checked the tappets etc. Although it is soon due for a timing belt replacement. According to the records, the first belt was replaced at 65000k's and it's just clicked over 120000k's.

I bought some chemtech diesel treatment to start using in the fuel hoping that it would help, however after one tank it hasn't really changed the economy.

Is there anything I may be missing in terms of getting better fuel economy? I don't drive it like I stole it and it seems to drive nice and smooth.

Your assistance is greatly appreciated.

Cheers

Goldey

[spudboy]

I've got the same car but in manual.

Is it possible that auto's don't do the same mileage? I don't know 'cause I've not had one, but as you mentioned, it does about 750Km on a tank which is 10L/100Km (and I do drive it like I stole it).

[Reads90]

Have you changed you Air filter . If this is dirty it will retrist the amount of air and increase the amout of fuel being used.
And are you sure none has played with the fuel mixture, IE does it smoke alot on hard pull away

[drivesafe]

Hi Goldey, I don’t if the Chemtech is an injector cleaner, if not, put some injector cleaner through the fuel and make sure you take the Disco for a good highway drive to give the injector cleaner a chance to do it’s job.

Cheers.

[drover81]

Does the 300tdi Disco have a MAF? I thought that if the MAF is stuffed, then the system overfuels...?

Maybe something leaking in the fuel delivery somewhere (pump/injectors/etc)...? or maybe even the tank...?

I seem to remember Inc had said something about driving it under load to de-glaze the cylinders etc. Does that cause poor economy, or just sluggish engines...?

[goldey]

The air filter is brand new and the only smoke I've seen is on initial startup which I've been told all of them do. I did follow my wife home from the shops (her in the Discovery and me in her car) and she does drive it like she stole it, and there didn't seem to be any smoke coming from the back.

I couldn't imagine the auto causing a 4l/100k difference over the manual. Maybe time to bithe bullet and take it in for a service and get the mechanic to check the fuel pump settings. This hurts as I'd rather spend my own time doing any work on the car, but this fuel economy is a concern.

Thanks for the replies.

Cheers
Goldey

[waynep]

That fuel comsumption is high for a 300 TDi. You should be getting around 10l/100km. According to LR official figures auto should actually be marginally better than a manual. Have you checked the accuracy of your speedo/odometer against a GPS or those highway odometer testing places ?
If your speedo is OK, it could be the injector pump or maybe the timing is out. However a gross timing problem would see a lot of smoke/diesel vapour coming out of the exhuast ( usually whitish ). There would also be a noticeable lack of performance.
If you're getting the timing belt done, any timing issues should be corrected then ( if your mech knows what he is doing )

If it was leaking somewhere, you'd surely be able to see it. ( puddles on the ground )

If someone has played with the injector pump to the extent that you're pumping that much extra fuel through, it would pay to get it checked ASAP. Doesn't sound like you have an EGT ( Exhuast Gas Temp ) monitor so your EGTs could be excessive, which will do damage.

[Reads90]

I couldn't imagine the auto causing a 4l/100k difference over the manual. Maybe time to bithe bullet and take it in for a service and get the mechanic to check the fuel pump settings. This hurts as I'd rather spend my own time doing any work on the car, but this fuel economy is a concern.

Thanks for the replies.

Cheers
Goldey


I have a Disco 300Tdi Auto and on saturday i drove it from Brisbane to byron Bay and back on quarter a tank of diesel. Which i was more than happy with :)

Go to the auto places and put in some diesle fuel additive. The reason being where you fill up depends on the quality of fuel. And supermarket fuel is chaep fuel and has less sulphur in it which is needed in the 300 Tdi. So get an addivtive to add this to the fuel , it also cleans the injectors too.

[Disco_owner]

I think he said he has replaced both the Air and Fuel Filters, Goldney what Tappet clearance was it when you checked them , according to RAVE should be 0.2 mm. if checked and 0.2 mm then no problems.

it is possible that the Bloke who owned the Disco prior to you has played around with the Fuel Pump settings for a Bit more fueling? this is easily checked and adjusted ...i tell you about this later how to set it back to factory..

check all turbo hoses with your hand to make sure there are no cracks and there is nothing loose.. it is possible air is escaping from your air intake .. check the wastegate actuator and boost signal line is NOT loose to the fuel pump wrong boost signal can cause excesive full delivery by the governor..believe me i had this problem before in my 300tdi..no boost signal getting to Fuel pump at all and fuel pump was sending fuel charge purely by the position of the governor..way too much fuel and black smoke...


just make sure the intercooler side of the hoses is tightended up on the alloy hose with the clamps . and you air intake hose is not showing any signs of degredation .. you may even want to upgrade your Elbow and straight piece with Silicone hoses, i've got part numbers for you if you're interested..not expensive..

Phew ..

now for the Fuel Pump Adjustment, i recommend if you've done all these checks and she is still blowing excessive smoke then we need to look at more fundamental adjustments , but i would not set about doing any checks / adjustments to your pump yet...

[goldey]

I haven't checked the tappet settings yet. It's on the to do list. I will also check the air hoses for cracks etc. Intercooler hose part numbers would be lovely and also steps to check the settings of the fuel pump, the last thing I want is to inherit engine damage because the guy before me wanted a bit more oomph.:mad:

Cheers

Goldey

[mcrover]

You have to look at the external differences first to understand where your loosing fuel economy.

The first thing would be the 245 75 muddies, they will bump up the fuel economy espesially around town as they are heavier to turn than the road tyres that are OME as well as they are larger so you need to use more power to turn them from a stand still so that is a huge jump when driving in traffic or with lots of stops at traffic lights.

The type of driving you do as in just to the shops or to drop kids at school means you are starting and stopping the engine lots more than someone doing more HWY K's.

I have heard that snorkles can cause a rise in economy but I cant say I have noticed but if it is lifted then add some as well.

Throw in some out of adjustment valve clearences and you can easilly get to the 14 odd mark.

Sschmez came out with a print out one time of his economy of his D1 300TDI auto and it was around the 15 mark as he always has a rack on and heavilly loaded as well as most of his driving is around melbourne.

Mine is a little better than steves but not by much these days as it is loaded most of the time with a rack and tent on the roof and normally carrying 120 odd ltrs of fuel, 235 85 rubber, 2" lift, snorkle on BFG AT's.

Try borrowing someones standard rubber one trip and see the difference.

[Dougal]

I think you need to do some more testing. One fillup can be close to useless for a fuel economy test, do a couple more (without the sand driving) and see how it goes.

[Reads90]

I think you need to do some more testing. One fillup can be close to useless for a fuel economy test, do a couple more (without the sand driving) and see how it goes.


I take it your are doing by fill up and the amout of K's . Check your speado is not out and it is recording less k's than you are doing. And Yes the speado and the amout of K's travel can be differant. I had a rangie that the speedo worked fine but for every 100 miles you did it clock up 1 miles on the milage (mmm i left it as it mean't i sold the car with low mileage :):))

[gorby]

You have to look at the external differences first to understand where your loosing fuel economy.

The first thing would be the 245 75 muddies, they will bump up the fuel economy espesially around town as they are heavier to turn than the road tyres that are OME as well as they are larger so you need to use more power to turn them from a stand still so that is a huge jump when driving in traffic or with lots of stops at traffic lights.

The type of driving you do as in just to the shops or to drop kids at school means you are starting and stopping the engine lots more than someone doing more HWY K's.

I have heard that snorkles can cause a rise in economy but I cant say I have noticed but if it is lifted then add some as well.

Throw in some out of adjustment valve clearences and you can easilly get to the 14 odd mark.

Sschmez came out with a print out one time of his economy of his D1 300TDI auto and it was around the 15 mark as he always has a rack on and heavilly loaded as well as most of his driving is around melbourne.

Mine is a little better than steves but not by much these days as it is loaded most of the time with a rack and tent on the roof and normally carrying 120 odd ltrs of fuel, 235 85 rubber, 2" lift, snorkle on BFG AT's.

Try borrowing someones standard rubber one trip and see the difference.
I agree with you. The oversized tyres and start stop/short journeys won't help.

[Reads90]

I agree with you. The oversized tyres and start stop/short journeys won't help.


Around town is where the Auto is worse with the fuel than the Manual. No real differance on the highway

[Disco_owner]

I haven't checked the tappet settings yet. It's on the to do list. I will also check the air hoses for cracks etc. Intercooler hose part numbers would be lovely and also steps to check the settings of the fuel pump, the last thing I want is to inherit engine damage because the guy before me wanted a bit more oomph.:mad:

Cheers

Goldey

here is the part numbers from one of my earlier posts, both the Elbow and straight piece.

http://www.aulro.com/afvb/technical-chatter/42281-silicone-hoses-tdi-300-a.html

[Reads90]

here is the part numbers from one of my earlier posts, both the Elbow and straight piece.

http://www.aulro.com/afvb/technical-chatter/42281-silicone-hoses-tdi-300-a.html


I have Allisport (d alot of Land Rover sports stuff) ones on my 90
Can get them off Eaby and posted here
AlliSport Land Rover Defender 300 Tdi 300Tdi Hose Kit - eBay Engine Tuning Parts, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles. (end time 11-Dec-07 07:00:00 AEDST) (http://cgi.ebay.com.au/AlliSport-Land-Rover-Defender-300-Tdi-300Tdi-Hose-Kit_W0QQitemZ260188627129QQihZ016QQcategoryZ72205Q QrdZ1QQssPageNameZWD2VQQcmdZViewItem)

Or other ones here
In differant colours:)
Red
SILICONE HOSE KIT for Land Rover 300 TDI landrover RED - eBay Engine Tuning Parts, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles. (end time 27-Dec-07 00:49:41 AEDST) (http://cgi.ebay.com.au/SILICONE-HOSE-KIT-for-Land-Rover-300-TDI-landrover-RED_W0QQitemZ180163954093QQihZ008QQcategoryZ72205Q QrdZ1QQssPageNameZWD1VQQcmdZViewItem)

Blue
SILICONE HOSE KIT for Land Rover 300 TDI landrover BLUE - eBay Engine Tuning Parts, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles. (end time 27-Dec-07 00:49:53 AEDST) (http://cgi.ebay.com.au/SILICONE-HOSE-KIT-for-Land-Rover-300-TDI-landrover-BLUE_W0QQitemZ180163954148QQihZ008QQcategoryZ72205 QQrdZ1QQssPageNameZWD1VQQcmdZViewItem)

Black
SILICONE HOSE KIT for Land Rover 300TDI landrover BLACK - eBay Engine Tuning Parts, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles. (end time 27-Dec-07 00:49:35 AEDST) (http://cgi.ebay.com.au/SILICONE-HOSE-KIT-for-Land-Rover-300TDI-landrover-BLACK_W0QQitemZ180163954063QQihZ008QQcategoryZ7220 5QQrdZ1QQssPageNameZWD1VQQcmdZViewItem)

[Disco_owner]

I paid $48.00 for the Elbow and straight Silicone hose Pieces and retained my alloy straight piece from TurboXS in Hornsby , that was the cheapest price around .. the Kit that you have inluded the link to is about 62 pound or $147.0 that's a big difference..


I have Allisport (d alot of Land Rover sports stuff) ones on my 90
Can get them off Eaby and posted here
AlliSport Land Rover Defender 300 Tdi 300Tdi Hose Kit - eBay Engine Tuning Parts, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles. (end time 11-Dec-07 07:00:00 AEDST) (http://cgi.ebay.com.au/AlliSport-Land-Rover-Defender-300-Tdi-300Tdi-Hose-Kit_W0QQitemZ260188627129QQihZ016QQcategoryZ72205Q QrdZ1QQssPageNameZWD2VQQcmdZViewItem)

Or other ones here
In differant colours:)
Red
SILICONE HOSE KIT for Land Rover 300 TDI landrover RED - eBay Engine Tuning Parts, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles. (end time 27-Dec-07 00:49:41 AEDST) (http://cgi.ebay.com.au/SILICONE-HOSE-KIT-for-Land-Rover-300-TDI-landrover-RED_W0QQitemZ180163954093QQihZ008QQcategoryZ72205Q QrdZ1QQssPageNameZWD1VQQcmdZViewItem)

Blue
SILICONE HOSE KIT for Land Rover 300 TDI landrover BLUE - eBay Engine Tuning Parts, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles. (end time 27-Dec-07 00:49:53 AEDST) (http://cgi.ebay.com.au/SILICONE-HOSE-KIT-for-Land-Rover-300-TDI-landrover-BLUE_W0QQitemZ180163954148QQihZ008QQcategoryZ72205 QQrdZ1QQssPageNameZWD1VQQcmdZViewItem)

Black
SILICONE HOSE KIT for Land Rover 300TDI landrover BLACK - eBay Engine Tuning Parts, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles. (end time 27-Dec-07 00:49:35 AEDST) (http://cgi.ebay.com.au/SILICONE-HOSE-KIT-for-Land-Rover-300TDI-landrover-BLACK_W0QQitemZ180163954063QQihZ008QQcategoryZ7220 5QQrdZ1QQssPageNameZWD1VQQcmdZViewItem)

[Blknight.aus]

a well tuned 300tdi driven perfectly in theory is capable of 10.5+ Kpl.

the opening things that will let it down have already been mentioned but a couple that havent need to be identified..

1. compression, how old is the motor, how many K's has it done?
2. timing as the timing belt stretches it can let the timing go out .5 degrees and more thats enough to upset things a little
3. injectors not up to spec for crack pressure, nozzle pattern and atomisation.

add a little of those three which are all unavoidable with engine age/milage to anything thats been mentioned before and your fuel consumption will skyrocket.

[justinc]

Just to add to what Dave said above;

Don't forget that aswell as making the little Tdi work harder, the 245.75's are about 10% out with KM. This means you would've travelled close to 990km instead of 900 on that tank, which equates to 13l/100. Add a tappet adjust, take into account timing belt wear, and possible otrher factors like thrashing it in sand and you may yet see 11l/100k. I haven't seen any auto disco Tdi's get 10l/100 with a mix of stop start driving and offroad use.

Highway driving without a headwind will get around 10 to 11l/100, but the auto is slightly higher geared in lockup than the manual and works harder, even without the 32"tyres.

Don't panic, a few adjustments and all will be revealed.:D

Overall, a great little engine and puts out an amazing amount when you realise it is only 2.5 litres.


JC

[mcrover]

When we first got ours I was getting 9.6l/100kms on hwy and a bit over 11 in town but then I have gone and added a winch, roofrack, lift kit, taller rubber and a heap of gear as well as a long range tank and probably a few extra KG's of mud in places that it doesnt wash out of easilly and now get on average around the 14 mark I think.

I get fuel at work as part of my package so I dont really check it that often.

If it isnt smokey or lacking in power then the mechanical problems will be less likely other than valve clearences.

Keep a close eye on your tyre pressures as well as they can make a pretty big difference in fuel economy.

[langy]

On page 155 of RAVE, LR say the 300TDi auto gets 13L/100k city cycle - new and standard. So 14L/100K, in a 10 year old car,bigger tyres with a bit of off road work and A/C on is OK.

[goldey]

Well, you're making me feel a bit better about the economy of the car. Thanks for that.

I got a quote yesterday from the local LR expert for the timing belt replacement and did a bad thing and told the minister of war and finance how much it was going to cost :eek::eek::wasntme: $900 :(.

I also used my gps to check the odometer this morning and found on my trip to work the odometer on the car recorded 8.3k's and the gps told me it was more like 8.7k's. Apply that to my fuel economy figures over the past two tanks and it suddenly goes down, that's a bit better :cool:.

I'll be doing tappets this weekend and checking all of my air hoses. The timing belt is due but it can wait till after Christmas I think. That's just rude, cruel and unusual the price they quoted for that. I am reasonably mechanically minded (have torn down and rebuilt numerous engines before) so may just buy the kit and atack the belt myself over the holidays.

Thankyou again gents for your help and suggestions. I do like the disco very much and as it is a long term proposition I want to get it working at its peak.

Cheers
Goldey

[Bushie]

Just to add to the above,

I've been getting around 9.8/100km for the last 6 months or so worse consumption since owning the vehicle (300Tdi -98 Defender) was 11.1/100. The leg across the Simpson in 2000 returned 10.7/100.

The Odometer is out slightly so I'd be checking that first (as others have said) with your combination of tyres. Things may not actually be as bad as you think.


Martyn

PS Last 6 months running has been Heathcote - Nth Parramatta & return each day (peak hour).

[agrojnr]

My last 2 tanks has given me on average 10.9/100km but mine is a 200tdi

I also have 2 inch lift, 32" tyres, rear draw system and roof rack.

I have just had my belt and water pump changed so I will see if it makes a difference

p.s. I drive mine pretty hard


Adam

[Kandy]

Well, you're making me feel a bit better about the economy of the car. Thanks for that.

I got a quote yesterday from the local LR expert for the timing belt replacement and did a bad thing and told the minister of war and finance how much it was going to cost :eek::eek::wasntme: $900 :(.

I also used my gps to check the odometer this morning and found on my trip to work the odometer on the car recorded 8.3k's and the gps told me it was more like 8.7k's. Apply that to my fuel economy figures over the past two tanks and it suddenly goes down, that's a bit better :cool:.

I'll be doing tappets this weekend and checking all of my air hoses. The timing belt is due but it can wait till after Christmas I think. That's just rude, cruel and unusual the price they quoted for that. I am reasonably mechanically minded (have torn down and rebuilt numerous engines before) so may just buy the kit and atack the belt myself over the holidays.

Thankyou again gents for your help and suggestions. I do like the disco very much and as it is a long term proposition I want to get it working at its peak.

Cheers
Goldey

Hi Goldey,
I dont know where your "local LR expert" is but a quote for $900 is over the top, I was quoted $500 for the 200tdi, a similar job, by LR experts at Marooka in Bris. The pommie forum/site "Difflock" has great stuff on timing belts for DIY. I had leaking diesel from my pump seal but you would have noticed that by now? It sounds like your pump has been fiddled with, hope so, cheap fix.

[UncleHo]

G'day Goldy :)

What is your location?? as there could be several knowledgable Landrover Mechs. in your area, and at prices a lot cheaper than $900 :o tell us were you are, and see what happens.

cheers

[goldey]

I'm in sunny Newcastle, where the beaches are golden and the bush is close by :cool::cool:

[Dinty]

G'day All I would be ringing Modern Motors Dungog 49 921486 and ask for a quote cheers Dennis:wasntme:

[goldey]

Spoke to Murray, he said I should be good for another 20 thou before looking at changing the timing belt. "They should be good for 80 thousand ks", his words. This means that I shouldn't need to do it until I rack up 145000 ks. Cool. Then again maybe I'll still do a DIY on it over the break.
Doing the tappets this saturday and also noticed my main muffler (centre of the car) has got a dirty big ding in it, good reason to chop it out and weld in a straight pipe and only have the rear muffler.

Cheers
Ian

[waynep]

I have 245/75 R16, snorkel, free flow muffler and regularly get 10l/100km.
( the speedo is only 1 or 2 km/hr out)
no pump tweaks excpet I did tweek the "stop" screw a little for better off boost performance. Seems to have made no difference to fuel consumption.
I run BP diesel if I can - seems to give maginally better fuel economy -might just be my imagination..