xantia esate TD low mpg :(

deano · Post by **deano** » 20 Oct 2005, 17:59

Hi,

having recently purchased another xantia diesel

was surprised to find the MPG very low, 36mpg. have changed the air and fuel filters and done the mpg again and still get 36mpg

The previous xantia same engine 1.9TD managed 44-48mpg doing the same journeys. so was expecting the estate to do slightly less but not 36mpg. Car has done 136k miles and has FSH for citroen uptill 126k and then an independant for tthe rest. The car has been used for towing a caravan, but don't think that will make much differance.

Basically has anyone one got any suggestions of things to look at to try and improve the mpg.

TIA

Deano

yangreen · Post by **yangreen** » 20 Oct 2005, 19:04

Binding brakes is usually a good one to check. Used to sometimes go as low as 42mpg in my Pug 306 with the same engine so 36 does seem low.

Oh and of course check to see if fuel is leaking anywhere - that'd affect it!

Kowalski · Post by **Kowalski** » 20 Oct 2005, 20:43

Binding brakes are the obvious thing, but a blocked exhaust can cause a suprising drop in fuel economy, I replaced the catalyst on my '97 Xantia with a non catalyst pipe and the economy improved by about 5mpg.

The timing being out can have a big effect on a diesel too, if you've got a later Xantia (96/97 on) with a catalyst and egr, you also get the electronic advance/timing control, and if that isn't working properly you can end up with your timing out. The egr system can malfunction too and affect economy.

Have a look at this topic:

http://www.frenchcarforum.co.uk/forum/v ... hp?t=16401

Somebody else was having similar economy problems with a Xantia estate.

deano · Post by **deano** » 20 Oct 2005, 20:56

Hi,

cheers for the replys guys, the brakes defo don't bind, will get it booked into the gardage to check the timing as well.

Kowalski, how do you get on with the MOT tests having no cat? or do you put it back on?

Cheers
deano

jeremy · Post by **jeremy** » 20 Oct 2005, 21:11

Has it simply lead a sedentary life - and choked up? Injector cleaner and an 'Italian Tune-up' might help.

Kowalski · Post by **Kowalski** » 20 Oct 2005, 21:15

deano wrote: Kowalski, how do you get on with the MOT tests having no cat? or do you put it back on?

The short answer is that the catalyst makes no difference to the MOT, diesels don't need a cat to pass an MOT.

That CAT on a diesel is supposed to oxidise gaseous hydrocarbons coming out of your engine, i.e. it doesn't do anything at all to the particulate matter coming out of your exhaust, and its those particulates that make the smoke that is tested for. What actualy happens is they get coated with a sooty tarry material, they need oxygen to oxidise anything and if they're nicely coated the oxygen can't get to the catalyst so they do nothing apart from hurting your fuel economy.

deano · Post by **deano** » 23 Oct 2005, 17:45

Hi

as both cats have now died on bot xantia's xud and hdi, where can i get decat pipes from? preferable online.

Cheers for any info.

Deano

Post by **philhoward** » 24 Oct 2005, 09:52

Kowalski wrote:Binding brakes are the obvious thing, but a blocked exhaust can cause a suprising drop in fuel economy, I replaced the catalyst on my '97 Xantia with a non catalyst pipe and the economy improved by about 5mpg.

A chap I know has a Pug 405 1.9TD, and knew someting was wrong (he had kept mpg records for the last 6 years) as his mpg was falling (48 to 42-ish). It was only when the exhaust actually started blowing and he had it replaced his MPG suddenly jumped back to 48 (bar the first tankful whilst was "sooting" back up!).

Diesel exhausts don't rot from the inside out as quickly as petrol ones, but they do get clogged a darned sight quicker!

As has since been mentioned, the "Italian Decoke" does work wonders! I gained 2mpg from my old Xantia TD and it suddenly became much more responsive to drive as well!