2.0. Hdi poor fuel consumption

[PeterN]

I think I may have mentioned this before but have only lately realised how bad it is. My latest 2.0. Hdi estate appears to be in good mechanical condition, doesn't smoke, brakes are not binding and I can't find anything else amiss but its only averaging 37mpg on journeys that my old one would do 50mpg+ on. I'm only getting about 500 miles on a tank, I have had a 1000 on the old one on our Scotland trip. It seems particularly bad on hills, about 15-20 mpg on hills that the other one did 25-30 mpg on, its better on level ground on long distances.

So far I have replaced the MAF from the good car and fitted a new thermostat, checked the injectors with a leak of test which gave three the same and one slightly less. Its almost identical to my old one which would do well over 60 mpg on a long run, this one has just about made 50 mpg driving with a glass slipper.

Don't know what to try next, any suggestions?

Thanks

Peter

[lozz]

Hi Peter.
How are you working out the mpg?

Gauge or just working it out off a full tank...

Tyres and pressures all good?

[PeterN]

Both, a tankfull is only lasting about half as long as on the other car, I have done a brim to brim check and it bears out the display reading. Tyres are OK as are the brakes although on the other car I have had soft tyres and binding brakes and it made very little difference when I fixed the brakes but it would still do over 60 mpg, again verified by top up tests.

Peter

[lozz]

Hi Peter.

Maybe both cars have had a totally different life style..
Eg. Your old one may of seen plenty of motorway miles or mixed..
And your new one as seen..round town action & little motorway use..

It may sound daft but it does have an effect..

My car (none pug) goes really crap on fuel at times,
Its past life was a 'motorway mile muncher..I have to take it out ..into the sticks once in awhile and let it chuff out some coal.

Perhaps adding a fuel adative ...& taking it out for a good sprint might help..

People say fuel adatives are Placebo's but its not true IMHO..

[GingerMagic]

Something else to consider Peter, is that some fuel gauges are a bit hit and miss...

Sometimes I get only 350-400 miles when the fuel light comes on, but I can only squeeze about £45 in the tank as it was still half full ( optimist )

This doesn't happen every time, but now my car is stood up for long periods it happens more and more.

[trufflehunt]

...., its better on level ground on long distances.

" They all do that, sir. "

Assuming that you've serviced the car, and replaced the various filters,
I'd agree with lozz's comment about an additive.

And maybe some enthusiastic driving, some stick.

[steve_earwig]

I'm wondering if the injector correction values would show anything, maybe they need a clean?

[PeterN]

I have double checked the consumption by brim to brim fill ups Ginger and 406 version 2 is definitely using a lot more fuel than version one, apart from measuring it I know by how often I am filling it up.

I Have always checked my fuel consumption by brim to brim fill ups, its not something I have just started doing, used to check the XMs every time we went to Scotland and I was getting 50 mpg+ from them with an IDI engine!, this one will just about manage 50 mpg driven very gently, the other one did an easy 65+ and I actually attained an indicated 70.3 going to Yorkshire last year but I drive very gently, rarely over 60 mph or 2000 rpm.

I am wondering whether to put the injectors from the old one into it although the existing ones show OK on a leak off test, I also wonder if perhaps the timing is one tooth out. This one doesn't go quite as well as the other one, not a tremendous difference but it just doesn't feel quite as lively.

This is a real disappointment to me as the other car was going fine until I stopped using it, it was just getting a bit tatty, then it got damp and now wont start, immobiliser fault. I now have what was an excellent car but is likely scrap if I can't sort the electronics, and a replacement that is trying to bankrupt me.

I have been offered the loan of a Lexia as I don't seem to be able to get mine back, so will see how that goes.

Peter

[stevewalsh]

Stuck EGR valve ?

Steve

[lozz]

Perhaps giving it a tin of egr cleaner ..might help..
I've used it before with good results..

[steve_earwig]

Stuck EGR valve ?

Steve

Clouds of smoke?

[PeterN]

No smoke at all and EGR disabled, inlet not getting hot.

Peter