You will use more diesel in cold weather and when doing short runs as it takes this diesel engine some 10 miles to properly warm up. Try using a main brand diesel as well. If the temp gauge is reading lower than it should, the thermostat may be be faulty, which would make a difference. The MPG you quote is not unreasonable when doing short runs in cold weather. All this assumes that the EGR valve is properly clean and working as it should. If you get a lot of black smoke when you pull away from a roundabout, for example, this indicates an EGR problem.

I would say that using injector cleaner won't make a huge difference. Have you checked the really obvious: leaks, tyre pressures. Is power ok? Obviously garages or home mechanics just change anything, when there is an art to diagnostics called 'common sense!!"

Have you cleaned out the inlet manifold and had the turbo vanes cleaned as I suggested and also have the turbo checked for operation ,having worked on plenty of these renault engines untll itsclear of crud then you may as well shove ßßßß uphill.Another problemis the MAF run the car without it connected if its just the same then its faulty.

Edited by Andy Bairsto on 04/12/2010 at 15:05

hi me again , i disconnected the maf sensor and it was no power on pull away ,so connected back together and power was back . i did put some injector cleaner in the other day and have noticed there isnt so much smoke , but it is still using diesel , thanks

No,if I remember there is a supply tothe glow plugs all the time the ignition is on if there was current going to the glowplugs all the time with the card out the battery would be flat in no time.I think there is a supply to the glow plugs for a short time while the ECU shuts down.

Edited by Andy Bairsto on 26/12/2010 at 13:12

hi does any body know how to test egr valve and also how easy is it to take inlet manifold of to clean thanks

hi fernando p , i do all my own repairs and i have just been out for a drive and glowplug light came on and lost all power , switched engine of then restarted and was ok , got home and put code reader on and came back with df 199 boost pressure sensor coherance btween boost pressure and atmospheric pressure , also airflow meter code , cancelled codes and went for drive and put code reader back on and it came up with boost pressure sensor coherance btween boost pressure and atmosheric pressure , i will have to check wiring , any help thanks

I dont want to point out the obvious but are your tyre pressures right and are all your brakes free from binding...