406oc.co.uk

Hi guys,
i'm not really having any issues with my car (405td with 150k on the clock) I serviced the car when i bought it, and only seem to get 46.8mpg out of it. I'm expecting 50+mpg. 75% of my driving is in town at low speed. My question is should i whip the injectors out and have them cleaned by a local diesel specialist (S&S Diesels services in bishop's waltham Nr Southampton)?
Thanks in advance.
Col

col,

If I was averaging that kind of mileage out of my 1.9td I'd be chuffed to bits!!!!
Throw some fuel additive in every second fill up if you want to be kind to the old girl, other than that regular (6 monthly) servicing should keep her ticking along fine.

Hi Col, that is actually pretty good consumption, considering it's town driving. The book figure is about 45mpg combined, and mine returns that or there abouts. The XUD is old school and not particuarly econimical by today's standards. Reconditioning the injectors should make a difference at that mileage. I would expect around £100 for the set. Have you tried some injector cleaner and an italian tune up?

You will almost certainly have a Bosch pump on that car, have you considered using vegetable oil?

Good to know i'm doin ok on fuel then
I was concerned with the intermitent use of veg oil may have a detramental effect on the injectors.
I do put a bit of fuel addative in it whenever the car is on Diesel.. i put 20-30ltrs of veg oil in it a month, the rest is diesel. I change fuel filters every 4000 miles and service every 6000 miles, and keep a spare fuel filter in the boot (with an allen key to change it!)
Thanks guys

Bigcol wrote:Good to know i'm doin ok on fuel then
I was concerned with the intermitent use of veg oil may have a detramental effect on the injectors.
I do put a bit of fuel addative in it whenever the car is on Diesel.. i put 20-30ltrs of veg oil in it a month, the rest is diesel. I change fuel filters every 4000 miles and service every 6000 miles, and keep a spare fuel filter in the boot (with an allen key to change it!)
Thanks guys

I found that veg oil was great in my XUD 7TE, as long as It wasn't more than about 20-30%.
I remember overdoing it one time and it was a bit lumpy on a cold winter start (one of those picture perfect frosty mornings) but it was fine once the engine was warm.

I used to treat the engine with some injector cleaner once in a while, but that was it.
I didn't change the fuel filter at all until I broke the housing when bleeding it.
A damn good engine the XUD. I used to get 47MPG with the Veg oil, without being conservative.

Veg oil is fine to run all year round, in Winter it needs to be diluted about 10% Petrol, this does have a detrimental effect on performance though.
A little engine oil in with the veg works wonders but is considered illegal ;)
Two stroke oil is amazing stuff in diesel! It highens the cetane rating, lubricates the pumps and injectors and allows for a cleaner burn of diesel. About 250ml in every tank full.

Check you have no intercooler/turbo pipe leaks. Can effect economy and performance. Change fuel filter. Maybe clean out intake manifold.

As the 405 has no EGR, the intake manifolds stay squeaky clean

are you sure its 46.8 and not 46.9?

What are the book figures for these old XUD engines? I think I looked at them before getting my HDi and decided they were not that economical - certainly not much better or similar to a modern petrol engine of the same capacity.

Did you get your figures from a VW site or summink?

The Xud is most probs more economical than the Hdi,
icouid be wrong tho,

I averaged about 47 out of my XUD. My HDi -- on the same journey, initially -- has averaged 59MPG.

You can make up the difference if you can run the XUD on veg oil -- even new oil from the supermarket is cheaper than diesel.

I was getting almost the same figures as my 2.1 with mostly around town and the occasional long run. With all these silly short journeys it's gone through the roof and I might actually do better with a similar output petrol but the moment it hits the open road ever the 2.1 would make the petrol look stupid. Unless this is a modern modern petrol - some tiny box that'll blow away in the wind.