Fuel average gone so bad after servicing

[Aman1]

Mercedes c220d 2019
Fuel average so bad this all happen after serving
Fuel filter , engine oil , air filter , oil filter
Everything changed . Fuel average was perfect before servicing . There’s no code on dash got it checked giving me like 14 mpg

 

[Aman1]

Mercedes c220d 2019 57890 mileage
Fuel average so bad this all happen after serving
Fuel filter , engine oil , air filter , oil filter
Everything changed . Fuel average was perfect before servicing . There’s no sings on dash . got it checked by local garage nothing came up on dignoes giving me like 14 mpg

 

[Aman1]

Recently serviced my c220d the mileage gone so worst its like giving me 14 mpg cunsuming fuel so much

 

[AlanGunn]

Are you getting 14mpg now.
Try it on a run.

 

[malcolm E53 AMG]

Welcome!

Check that the engine coolant system thermostat is working correctly if it’s stuck open the engine will overfuel

 

[Aman1]

Are you getting 14mpg now.
Try it on a run.

Hi yeah it’s like 14 mpg there’s no sings on dash plus no code popes up on dignoes. The radiator fan on most of the time but the temperature is on 90 on the dash . The engine is bay is hot that you can’t even touch it .

 

[Aman1]

Welcome!

Check that the engine coolant system thermostat is working correctly if it’s stuck open the engine will overfuel

Hi yeah it’s like 14 mpg there’s no sings on dash plus no code popes up on dignoes. The radiator fan on most of the time but the temperature is on 90 on the dash . The engine is bay is hot that you can’t even touch

 

[KennyN]

Its not doing a DPF regeneration is it ?

K

 

[Aman1]

Im
Not too sure tho . Wht should I do to the start stop doesn’t work plus the fun on even on a 3 mile trip

 

[Aman1]

But there’s no sign on dash plus car pick up is smooth

 

[KennyN]

But there’s no sign on dash plus car pick up is smooth

Dont think you get a sign on the dash during a regeneration , the signs are really poor MPG , slightly higher idle speed , very hot exhaust temperature.

Take the car for a decent run 20 mis or so , keep the revs up to facilitate the regen then rest your average consumption and see what it is after.

K

 

[w204benz]

Unfortunately I have no idea what could cause such high fuel consumption, but as you mention 14mpg - is the fuel gauge dropping at an alarming rate or are you going off the computer reading?

On my (earlier) C class I have noticed that after a fuel consumption reset, it always starts at a default value until it has enough data to calculate the actual average consumption. And that value is 14mpg!

Perhaps your fuel consumption hasn't increased and the computer is showing the default value for some reason?

 

[Aman1]

Dont think you get a sign on the dash during a regeneration , the signs are really poor MPG , slightly higher idle speed , very hot exhaust temperature.

Take the car for a decent run 20 mis or so , keep the revs up to facilitate the regen then rest your average consumption and see what it is after.

K

Thankyou

 

[AlanGunn]

Was the fan running like that before the servicing.
Who did the work ?.

 

[fabes]

How about other (simple) things?
Stuff that should have been picked up on a service, but as you're running out of ideas....

Sticking brakes (calipers or foot / hand brake)?
Tyre pressures too low - unlikely but it may not be just one thing....
Have you reset the trip and been on a 30 mile trip where you can sustain at least 50 mph as you should see around 50 mpg?
Have you measured the actual fuel consumption via the pump and not just the on board trip in case that's giving you incorrect data (unlikely, but....)
Are you carrying a lot of dead weight in the car (or dead bodies in the boot!)

You've probably already gone through such a list, but just to go over the simple / simple to fix things

 

[brandwooddixon]

Fuel filter , engine oil , air filter , oil filter

Fuel leak after changing the filter?

 

[Aman1]

Unfortunately I have no idea what could cause such high fuel consumption, but as you mention 14mpg - is the fuel gauge dropping at an alarming rate or are you going off the computer reading?

On my (earlier) C class I have noticed that after a fuel consumption reset, it always starts at a default value until it has enough data to calculate the actual average consumption. And that value is 14mpg!

Perhaps your fuel consumption hasn't increased and the computer is showing the default value for some reason?

Thankyou

Fuel leak after changing the filter?

no there’s no leak I got it checked .

 

[Aman1]

Was the fan running like that before the servicing.
Who did the work ?.

Yeah it was . Local Garge

 

[sonic]

Yeah it was . Local Garge

Take it back to the local garage, tell them what has happened.
Have you checked the fuel consumption full tank to full tank. Dont assume to computer is correct.

 

[Bay Leaf]

I'm inclined to agree with w204benz regarding the consumption re set, one of my cars does that after re connecting the battery.
Do you leave your air con switched on as the fan will run when the air con is operating.