Fuel economy plummeting
 

Hi All. I am new here and hope someone may be able to help. I have a 2010 diesel Outback and it has been a bit of a mare. In the summer I needed a new clutch fitted and when the car came back one of the battery terminals was loose and jumped off when my wife was driving. When it was re connected the abs light was on and the brake pump unit was goosed. Took a while to get a second hand one but got one from a Legacy, all the same part numbers etc. . New one fitted and now the dash display wont recognise 6th gear for some reason( all the gears work fine just not showing up) and the mpg has slowly dropped from 46mpg to 39.3mpg. Does anyone have any ideas if any of these things are connected or possible causes for the drop? Its the nicest car I have ever owned but sadly proving to be the most expensive. Thanks in advance.

Meant to say that we have also had a look to see if there are any fault codes relating to anything connected and nothing is showing up. Cleared all old codes and it is now showing no faults apart from one for the air con.

Post this on uklegacy.com
there's a few stories on the diesels.

Thanks Stamina. I have just done that and will see if I get any joy there.

Could a dud injector be causing car to run rich and impacting fuel?

Nothing wrong with the fuel consumption, its the time of year with longer cold running to get up to temp, & the winter fuel additives in the diesel always cause consumption to rise, Subaru diesel consumption is worse than anything comparable.

I have never had a car that dropped mpg like that in the winter Motors. It has been steadily dropping since September. Hasn't been cold enough for most of the time to make any difference. My father in law has an auto one a bit newer and even thats getting 43mpg.

there is an issue where they can pass diesel into the sump and this will cause a drop in MPG but more noticeable a rise in oil level........

Yes Stockcar. I have found that this is the issue. It is caused by a faulty suction control valve on the fuel pump. Supposedly they have plating on the insides that corrodes and causes over fuelling. The motor factors are going to phone Denso to get the right bit on monday. New oil and filters ready to go on too. Subaru are well aware of the problem but said nothing about it when I spoke to them. They have the part on back order with no date of arrival at £230!!!

Think someone was selling one on uklegacy
in the for sale section

Thanks Stamina but its the wrong one of course. .