Td5 High Consumption

[Phil]

I thought my '02 110 was using more fuel than usual so I checked the consumption and it's down from around 28mpg to about 20mpg. I haven't changed anything, it had a full service recently, it's running 'normally' and there's no evidence of fuel leakage. I know the weather's been cold, but I don't believe that could account for the difference!

I'd like to get back to a more economical rate of fuel use; could anyone suggest what I should check or look for?

Many thanks,

Phil.

[JST]

cold weather meaning more overfuelling to help warm up? heavier than normal alt load - screens/seats/heaters, lots of stop start driving, leaving the vehicle ticking over whilst demisting, warming up, pulling lots of people out of drifts.

Just some thoughts, i presume none are applicable?

[Phil]

Hi, James, you are right to suggest all those things could be relevant and I would expect higher consumption because of them. But, and I might usefully have made this clear in the original post, I measured the consumption over an 800 mile round trip on which I've always previously got around 28mpg. Despite the current weather, there was nothing other than the lower temperature that was different from usual. In fact, as the roads were almost deserted, I would have expected to match or beat 28mpg because I had no hold ups in traffic and sat almost the entire time at a steady 60mph.

If it's not leaking I presume it's over-fuelling? Could that be due to a sensor problem, for example?

Cheers,

Phil.

[martifers]

MAF sensor working correctly? Might explain it. Nanocom or other diag would be able to give you a definite answer there.

[Phil]

MAF sensor, right; I don't have access to a diagnostics set. I'll take it out and clean, and see if that makes any difference. Is M19 2651A the correct part number if I need a new one?

Thanks,

Phil.

[martifers]

I don't have microcat to hand, but someone here will be along shortly. Ask at your local LR dealer or specialist as they should be able to plug you in to check things over. If not, i'm sure someone on the forum in your area might be kind enough to pop round with said diagnostics if a brew was offered.

[disco_al]

what about the fuel pressure regulator on the back of the head? don't they leak down and onto the undertray (not sure if the defender has got an undertray though, so may not be applicable)

[Porny]

MAF sensor, right; I don't have access to a diagnostics set. I'll take it out and clean, and see if that makes any difference. Is M19 2651A the correct part number if I need a new one?

Thanks,

Phil.

Part number for MAF - MHK100620

Only buy a genuine part or OEM (siemans/VDO) do not get tempted by any of the cheap ones on EBay or Similar!!

Aftermaket copies do not work as per genuine - and do not give the ECU the correct values.

Expect to pay between £65 and £80.

Would be worth getting it plugged into some diagnostic equipment by some one who knows what they are doing (i.e. not someone who only thinks they need to look at fault codes!!)

As well as MAF, could be the MAP sensor (Manifold Absolute Pressure) on the intake manifold, a failed EGR valve (quite common) or even a few other things.

Have you checked your oil level isn't rising?

Ian

[Phil]

disco_al, I've checked the fuel pressure regulator and it's definitely not leaking although the original one did!

Ian, thanks for the MAF part number and buying tips. Given the other possible faults, I think it would be best to get someone competent to read the diagnostics. I'll have to ask around, I don't think my local garage would tackle anything more complex than reading fault codes. Can you give me some idea of the sort of thing that should be checked and might show up?

I hadn't noticed the oil level rising nor any contamination, but I'll dip it again tomorrow morning (it's dark now). I presume you're suggesting fuel might be getting into the oil, is that correct? Pardon my (extreme) ignorance but what causes that to happen?

Cheers,

Phil.

[mobyone]

it is worth checking things like brakes sticking on slightly too, that will increase your fuel consumption. and it is something you can do before you pay out your hard earned.

richard

[vexedfoxy]

I am sure they tech guys that have written about are on the right lines but on a much more simplistic level Open roads? No one about? where you going much faster than normal, tyre pressures? just a thought.

[DaveSIIA]

I've noticed a slight increase in fuel consumption of my 300Tdi during the winter months (every fill up, mileage/quantity/cost have been logged for the past 12.5 years). The vehicle does a regular run from the Peak District to Glasgow & back most weeks. Fuel usage on that run increased by ~10% from November, which I have put down to winter fuel additives.

The vehicle is regularly serviced and there are no electronics to interfere with the fuelling, so not a lot to change there. Interestingly, consumption improves during the summer months.

[Phil]

Thanks for the suggestions but it's not the brakes binding or me taking advantage of the open roads! I'd expect slightly higher consumption in winter, certainly, but 20mpg instead of 28mpg seems beyond that. Once it stops raining I'll clean the MAF sensor and see if that helps, I think I'll also take the EGR out whilst I'm under the bonnet. I'm looking for someone locally who has a diagnostics set and can use it so if none of this works I'll have to wait to see what the computer says.

Cheers,

Phil.