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2008 mondeo TDCI fuel economy
steve m - 14/11/11 at 08:11 PM

Hi

My Mondeo, 2008/TDCI used to be ultra ultra economic to drive, and according to the onboad computor
averaged, 40mpg,

Even towing, it was up in the high 30's

That was a year ago, and now i seem to be averaging around 30-33 mpg
and towing 28-30 ish

What seems to be the problem? and its not my right foot!!

It has been serviced, yet i do suspect the fuel filter was not done, only a hunch, but.........

The engine is also, on start up, like a tractor, very very noisy, yet next doors diesel VW taxi, with 330miles on the clock is nothing
as loud as My mondeo with 36,000

regards


pekwah1 - 14/11/11 at 08:14 PM

yep filters and stuff would be a good thing to check.
also the MAF sensors seem to massively effect MPGs if they're screwed.....


BigLee - 14/11/11 at 08:21 PM

Clogged up EGR valve is a common problem. Also, if it was main dealer servicing, I would check to see if the air filter has actually been replaced. The turbo pipe often splits which causes issues. Main dealer wouldn't notice as the computer can't diagnose it!
Oh, and check your tyre pressures. Sometimes its the simple things...!


steve m - 14/11/11 at 08:29 PM

This is my first ever diesel, so, were is the MAF and EGR ???????????


BigLee - 14/11/11 at 08:40 PM

Check the other things first. They're easier! My mate runs a 2.2tdci and his Exhaust Gas Recirculation valve was front left as you look with the bonnet up. We blanked it off with a plate off eBay. His car has run perfectly since. Check YouTube for a tutorial.

quote:
Originally posted by steve m
This is my first ever diesel, so, were is the MAF and EGR ???????????


steve m - 14/11/11 at 09:00 PM

Ive just bought a blanking plate off ebay

Now tell me the pit falls of fitting one!!!


steve m - 14/11/11 at 09:02 PM

Oh

Tyres were all about right, rear left was 1 psi down,
and the air filter is clean, but a halfrauds item,
and funny thing, im sure my economy dropped since, when i fitted it??

could be the problem?

steve


nick205 - 14/11/11 at 09:06 PM

Steve,

What size engine is it? 1.8 or 2.0

40 mpg seems a little low to start with to me, I'd expect mid to high 40's.


Peteff - 14/11/11 at 09:08 PM

quote:
Originally posted by steve m
Ive just bought a blanking plate off ebay

Now tell me the pit falls of fitting one!!!


I was often warned that blanking off can send you blind


steve m - 14/11/11 at 09:11 PM

its a 2.0, tdci

the trip computer used to say avereging 48mpg, but surely that cant be right!!


And i have never run any other fuel, than pump fuel, despite my nagging head that i should


AndyW - 14/11/11 at 09:25 PM

I used to have a 2.0 tdci and it sounded like a tractor from the day it was new, and sounded exactly the same when it had done 110k miles after 3 years. I was averaging 45+mpg but cant remember what it was averaging at the end.


MikeR - 14/11/11 at 09:50 PM

I'm watching this with interest. My old focus 2.0 tdci used to do low 50's on the motorway. Upgraded to an smax (which i appreciate is a few hundred kg heavier and a larger frontal area) but i was disappointed to only get 44mpg on a motorway despite sticking to 70 or below and using cruise.


AdrianH - 14/11/11 at 10:03 PM

My even older 2.0 TDDI Estate with 181,000 on the clock does around 44 mpg will get to 46-47 if I drive light footed and keep the speed within the limits of the motorway.

I would try the MAF filter, but also just check none of the rubbers are blowing especially between the turbo and the intercooler.

If done your own service ensure you have used the correct grade oil.

And mine really does sound like a tractor, being the TDDI does not help neither does the conversion I did to solid flywheel after the old one started to give way.

I would be expecting better mileage for the TDCI

Adrian


JoelP - 14/11/11 at 10:21 PM

Strange how fast technology has moved there really, one of the volvo estates now gets over 70mpg. Bonkers compared to just a few years ago.


steve m - 14/11/11 at 10:32 PM

"I would try the MAF filter, but also just check none of the rubbers are blowing especially between the turbo and the intercooler. "

oooh, sounds coool (haha) ive got an intercooler, on my diesel, so were the fcuk is it !!


Ninehigh - 15/11/11 at 05:38 AM

Couldn't tell you but my one is getting about 42 now (missus drives it hard at times too, and it's nearly all town driving) after 100k.. and all the servicing it's had is oil changes.

I can look it up in my Haynes book if you wish, but mine's the 2005 model (if yours is the newer one it might be different)


snapper - 15/11/11 at 06:22 AM

Similar problem with my 53 plate TDCI would run 50 mpg on a run. Mid 40's to work now dropping to early 40's
Injectors leaking have bought special tools
Intercooler pipe split 3 months ago, the one from EGR.
Will clear out the EGR next.


Ben_Copeland - 15/11/11 at 07:39 AM

My 2.2 tdci regularly get 23mpg average but that's cos I'm using all of its 155bhp

It's done 40k and is quite happy to cruise at 45mpg at 75.

Lots of things could affect mpg, but it might be lots of little things that added together make big difference. Cleaning out pipes and throwing away the halfords crap filter will help. Also check that when you put air filter in the air box lid is sealed down properly.

[Edited on 15/11/11 by Ben_Copeland]


FASTdan - 15/11/11 at 08:02 AM

Gotta say now that its lights on time of year I'm only seeing 35mpg from my 2.2 ST TDCI. 46mpg on the motorway with cruise control set to err 70'ish lol.

Slightly concerned about mine - my journey is only 8 miles, lots of up and down hills and junctions so perhaps its to be expected? I do have a whistle when on boost though so I suspect I have a split pipe somewhere?


sdh2903 - 15/11/11 at 09:09 AM

quote:
Originally posted by Ben_Copeland
My 2.2 tdci regularly get 23mpg average but that's cos I'm using all of its 155bhp

It's done 40k and is quite happy to cruise at 45mpg at 75.

Lots of things could affect mpg, but it might be lots of little things that added together make big difference. Cleaning out pipes and throwing away the halfords crap filter will help. Also check that when you put air filter in the air box lid is sealed down properly.

[Edited on 15/11/11 by Ben_Copeland]


Jesus, I was toying with the idea of swapping my st220 for an st tdci because I was sick of 25mpg dont think I will bother now!!

Back to the original topic, different engine but same principal, cleaned out the egr plenum on my dads s60 d5 at the weekend and couldnot beleive the amount of gunk and crap that was in there and the engine still able to run. Afterwards the engine is so much quieter, smoother and giving around 5-10mpg better.


quinnj3 - 15/11/11 at 10:34 AM

Hi Guys,

To me even early 40's mpg is wee poor for a modern 4 pot 2 litre diesel. As everyone says check the egr valves and MAFs. Make sure all pipes are good and secure with no leaks etc.

Oh for comparison my 2003 318CI 1995cc 140bhp petrol does 38mpg comfortably with a light foot and no motorway driving, all terrible N.Ireland B roads.


brookie - 15/11/11 at 06:57 PM

i got an 2005 2.2 st mondeo and i get 40/41 mpg m8