I have power loss problems and poor fuel consumption. Initially, on cold mornings starting was difficult - as if the heater plugs were dead. Once started it seemed to run quite well. Consumption soon dropped from 50mpg to 46mpg. Then it developed very intermittent but significant power loss. Mileage is now 97000.

It hasn't been right since a short while after a service, which apparently included fuel, oil and air filter changes. My regular garage changed the heater plugs. Two were dead. It gave a minimal improvement to starting and once running it was just the same as before. It went for another service and I said it was still a problem. They couldn't find anything and suggested waiting for a fault code to occur. Then it fairly suddenly started producing smoke, had less power and it indicated a fault. The garage said it was the EGR valve and replaced it. The smoke stopped but it still lacked power and consumption was still poor - Based on very few miles since the EGR valve change, I get 45 or so mpg when I try very hard for economy, but I know it should do 55-60mpg when driven that way. I see as little as 20+mpg if I try to drive it moderately hard in town, but with the chronic performance it accelerates slowly. On a cooler morning it still has the starting problem. After the service the garage had said that the engine was quite dirty and suggested a Terraclean. They also suggested Japanese cars are not the best for Diesels. So I had it cleaned. Maybe it runs more smoothly, maybe I am imagining that it runs smoothly, but apart from that it is no better at all. It has been parked-up since I got back from the terraclean on Monday and I'm using the bike.

I have had the car for 50,000 miles and keep a close eye on consumption figures. I do 15,000 a year, journeys almost all over 10 miles with over half that commute on the open-road at 50mph+. Roughly half my mileage is on two 135 mile motorway runs at 70mph every other week, which is why the car's average speed shows as 43mph, quite high. Oil consumption has been roughly measured and is higher than I would like, but at about 7000 miles per litre I presume it is OK.

Someone I know in the trade says the garage has a decent reputation. I know quite a few happy customers and I have used them for 6 years.

I would be very grateful for ideas. I have thrown over £500 at the problem already and am reluctant to spend more without getting information on the cause.

Edited by tim-cumbria on 20/05/2015 at 09:23