No update in regards to fuel economy improvements. I did swap out the factory air filters for K & N and it has made 2 l/100 km worth of difference, now averaging 16l/100km to 19/100km as opposed to high teens and low 20s

Update on the supercharger noise upon shutting off the vehicle. The dealership replaced the supercharger tensioner, but that did not fix the issue. The service advisor pushed to have the entire supercharger replaced under warranty, but Jaguar Canada refused him on the basis that the car is not giving out any fault codes and it's not affecting the drivability. I have since opened a case and requesting the supercharger replacement - fingers crossed.

 

Update:

Fuel economy averaging 26L/100km (9 MPG), range on full tank ~300 KM at best.

Took it to the dealership. They charged flat rate of $200 for inspection, found nothing and said - "it all depends on driving style". Okay.

 

Not sure I am understanding.

Have you filled the tank, driven a number of miles and re-filled to determine Fuel economy?

 

I tested the fuel economy by filling up the tank to the brim, resetting trip A to 0, driving over a period of time till the tank was nearly empty, about 8 KM Range reading on the center display. I filled up the tank again, roughly 61L of fuel out of 70L fuel tank capacity. The trip meter (Trip A) read 308 KM. So my math dictates I travelled 5 KM per L of fuel or 20L/100 KM or 11.7 MPG. This reading has been repeated several times, mostly city driving.

 

After determining the 20L/100 KM reading was accurate, my current reading has shot up to 25 to 26l/100KM. Ill be confirming the number inxe I fill up again, but again, its coming out to ve accurate.

No abnormal driving or engine sound. Tires are 6 months old. Wheel balancing, wheel alignment and correct pressure has been double checked.

Intake has been walnut blasted and engine carbon cleaned (if that is relevant).

Not sure whats going on

 

There is definitely something badly wrong, that fuel economy is woeful.
Two things I would now get checked - the MAF sensors and the oxygen (O2) sensors.
I think on the X250 3.0 SC the MAF sensors are on top of the air intake tubes one each side near the air filter boxes and if so they are very easy to remove, just a couple of Torx screws on each and an electrical plug. Take them off and clean them with dedicated MAF sensor cleaner in a spray can, I use CRC brand. Spray the little wires (two sets in each sensor), let dry for a few seconds then repeat four or five times. This whole job takes only a few minutes so that is the first thing I would try, a faint chance it fixes the fuel economy problem but worth a try.
If that makes no difference then look into getting the O2 sensors checked out and maybe replaced (not cheap though), one or more dodgy or failed O2 sensors can have a big effect on fuel economy.

 

Thank you for the response. When I had the oil change done, give or take 2 months ago, I decided to replace the cooled seat filters, air cabin filters and finally the two air intake filter with "Performance" K n' N filters as I got them at a really good price. The fuel economy problem was an issue well before this. Since the filter were new - pre oiled, I had my mechanic (an Audi VW specialist) clean the air intake, and he didnt have to oil them prior to installation. There is a known issue with K 'n N air filter over oiling causing the MAF to get covered in that oil. Ill definitely open up the air box and clean the sensors myself.

As for the Oxygen sensors, I can take it back to the dealership and specify checking the O2 sensor, but as per my experience in the past, the tech wont touch anything unless scanning the car shoots any code. I dont have any fancy scan tools, but to my understanding, a bad o2 sensors would trigger the engine light or atleast give out a code on a mediocre OBD scan tool.

I'm glad I have something to look into though, will update if the above suggestions result in any improvements.

Thanks again!

 

It would be advisable to put the aftermarket air filter to the side for now and go back to stock paper. That goes for any variable mixing up standard configuration during troubleshooting.

Gas mileage at this level should show in diagnostics running too rich at part throttle. Is there more smoke in the exhaust? You may even go for a roller emissions test and a failure there could at least be something more to show the service adviser. There is definitely something messed up with the air/fuel ratio on this thing.

 

Booked in for emission test. I should've thought about before since I have no idea where all the fuel is being dumped. I have not noticed the exhaust smoke getting dark, neither have I seen any abnormal exhaust residue building up on the lower rear bumper.

Thanks!

 

Took the car to my mechanic, he attached the diagnostic tool and wasnt able find anything. Emission testing that I booked for turned out to be specific for heavy duty diesel trucks only. No shop within Ontario is offering emission testing on petrol vehicles as Of April 2019. He agreed that the fuel economy numbers were absurd, but was quick to point out that all Petrol powered Jaguars tend to consume more fuel than what theyre advertised to, and numbers only get worse over time. Since there are no faulty codes, any visual sign of excessive smoke or sign of filter oil on MAF. Changing out the O2 sensor is the next stop.

 

Hello
i hope you fixed the issue, described above.
Could you please tell me, did you fix the issue? What had happened with your car? What was the root cause?
It seems i have the same issue. It happened after i made stage 1 upgrade. Exactly the same numbers.
I would be grateful if you tell me how you fixed it

 

Did you see my video on my 2015 xf Cooling and Supercharger Coupler upgrade,didn't cost me much to do the whole thing

 

Hi Dennis,

I think you meant to repsond to his other post

 

My bad, if you guys need help let me no, I'm here to help, I've changed a few Couplers on members cars ,I find the solid one is my favorite, quiet and reliable

 

hey what do you mean replaced a few couplers ?
what couplers where
I have bad Fuel economy too on 14 xf
I think I here a vacuum leak under the hood getting a smoke machine soon