...but everytime after travelling approx 1/2 mile from cold start, the engine starts to splutter slightly and knock as if the automatic choke stays on whilst revving you can hardly notice it but when staying at same speed, for example 20 mph in second or 30 mph in 3rd gear, as when in traffic it is very much more noticable.
So, it happens on every cold start, irrespective of whether it is after a pretty cold night, or a warmer morning?
By 'while revving' presumably you mean 'while accelerating' rather than 'at high revs'?
I have taken car back to dealer, they checked it over and said it is "diesel knock" which is acceptable because of age, mileage and general wear and tear and because the onboard computer is not recognising a fault they can't actually fix it.
Oh, that really is an unacceptable attitude. Did they actually tell you, when they were selling it to you 'don't expect it to work, it is a crap car and it is worn out' - of course they didn't!
And this bit about the on-board computer; yes, many things show up as error codes, but not everything. What they are really saying is 'we are not competent to do anything beyond the obvious (and it is your problem that we are not competent)'.
This is just wrong.
Car is on '59' plate 42,000 miles.
You'll find that there are people with 150 - 250 k miles on their clocks here, so their argument that the car has done too many miles - at 42k - to work is laughable.
...warranting my fuel injectors for 12 month, because I had test done on injectors which cost £200...
That's just weird; you've got a problem, you've paid for some work to be done on something that didn't turn out to be the problem, and they've responded by giving you a warranty on the thing that wasn't the problem.
Presumably, you took the car to some independent garage (or maybe Ford?) and it was their advice to get the injectors tested? Or, did you suggest to them to test the injectors? Was there any discussion of the other problems that it could be?
the mondeo tdci 1.8 titanium x uses the transit connect engine,
There is engine sharing all across the Ford range. You could easily say that the Transit Connect uses the Mondeo engine and it would be equally correct - probably more so if the Mondeo got the engine first, which it probably did.
Any argument that 'this engine is noisy because it is used in the Transit Connect', which is what they seem to be saying, is quite interesting because
- the noisiness, or otherwise, is quite dependant on the installation and the sound insulation and deadening thereof, so the argument is flawed
- you are not complaining about engine noise, so the argument is not relevant to the point at issue, that of the fault which exists with the car
- if you can get them to put it in writing you'll have a good case in court, because of the above two points - this alone isn't enough to win the case, but it will make them look very stupid, which always helps
put the engine through diagnostics and nothing flags up, "they can't fix it if it's not broke scenario"
Nonsense; it is broke, just it is broke without a diagnostic fault code. They can't (or maybe won't) fix it because they are useless and won't try. Or, possibly, they know that it will cost them money, and they are not happy about that prospect.
I've mentioned a court case - it is probably undesirable to actually go to court, but it helps to be prepared. A conversation with trading standards to find out where they think you stand and maybe a stiff solicitor's letter could well be in order as could be mention of rejecting the car, after finding out what chance you have of getting the money back that you have spent.
As to the real fault (which is probably irrelevant, because dealing with the legal and organisational aspects is probably what counts), the stuff that comes under the heading 'the usual suspects' for a diesel, for example:
- fuel filter
- fuel pump
- injectors (should be able to eliminate those, after the testing that has already been done)
- early stage of DMF failure
are all open to question, but I think I'd have to add:
- ECU cal
- temperature sensor
and I'd have to ask about the service history (oil change and when the fuel filter was last changed and was a quality part used). I think you could also ask whether it is any better on 'Premium' fuel (Shell Vpower/BP Ultimate), although it clearly a car that only runs cleanly on premium fuel would be unacceptable.