I have a 2007 159 and after months of trouble, chugging, coughing, sluggishness (you get the picture) etc...and one expensive breakdown later... I had my EGR blanked after it had stuck open from carbon build up and the swirl flaps removed after becoming heavily clogged from this, and had the system cleaned up real nice.
The car is an absolute dream now, and has continued to be....
Except....I have noticed something rather frustrating going on inconsistently with my MPGs/fuel consumption and wondered if anyone can give me some technical advice into what on earth is going on as its costing me a lot when it happens...
So, firstly, before I start I have manually measured my MPGs. I've done this 4 times and it is spot on to my Trip A Average MPG reading.
So, the issue I've noticed is every so many miles my MPGs drop to around 30, and no matter how I drive it won't go up. I can't figure out if its every 70, 100, 150, or 500 miles but it happens whenever it feels like it - its not consistent.
It lasts for a good 30-50 miles or so before going back to normal.
So, whilst driving at 60, around 1800 rpms, my current MPGS don't go higher than 35. This was on a flat. Uphill or in traffic its as low as 7-17mpg on average.
If i take my foot off the accelerator it takes ages to go up to 99.9 - i usually have to put my foot on the accelerator again before it gets there.
Then when its fine again, still driving at 60, and around 1800 rpms, its back up to 50-75 current mpgs on flats, and i've even measure 58.1 going up hill!!
So what's going on when its dropping because I've used a return journeys worth of fuel in a single journey.
Does anyone know what on earth is going on? Is it normal for EGR blanking because it doesn't seem right to me?
And i thought my fuel consumption should be better by 12%....which it is when it's fine, but then the drop is making up for that!!
As i said above, aside from that, i've not noticed any sluggishness. It's been a dream to drive, but I can practically see my fuel gage move as if I had a V6 again...just without the V6 engine! Haha!...
I drive 25 miles to and from work. This usally takes me 25-35 mins and on a good day my Average MPGs are 51-54.
And when its bad my average is 28-32 :-( so almost double the fuel!!
Any comments appreciated.
Thank you :-)