MPG has just fallen of a cliff after service

[Scruffy]

Last week I had my T6 serviced, new brakes all round but nothing else special was done to it. On Saturday and Sunday I drove to Leicester for work, down the M1, foggy so took it easy, no head wind, no rush, and the week before same journey, 41mpg, and I would have expected the same or better, this weekend 29. I've checked the tyre pressures, all fine, I can't think of anything else obvious to check ( I even checked the handbrake several times). This van has done 105k and overall average was always in the high 30's , with many motorway trips seeing mid 40's and more, ( brim to brim calculations), I never filled up under 600 miles and now I've done 450 with only 55 left according to the MFD.

What reasons could lead to such a drop in mpg overnight? and also is there anything that could occur on a service by mistake, that could lead to this result? Help please.

 

[DaveD]

Last week I had my T6 serviced, new brakes all round but nothing else special was done to it. On Saturday and Sunday I drove to Leicester for work, down the M1, foggy so took it easy, no head wind, no rush, and the week before same journey, 41mpg, and I would have expected the same or better, this weekend 29. I've checked the tyre pressures, all fine, I can't think of anything else obvious to check ( I even checked the handbrake several times). This van has done 105k and overall average was always in the high 30's , with many motorway trips seeing mid 40's and more, ( brim to brim calculations), I never filled up under 600 miles and now I've done 450 with only 55 left according to the MFD.

What reasons could lead to such a drop in mpg overnight? and also is there anything that could occur on a service by mistake, that could lead to this result? Help please.

Are the brakes binding? Go for a ten minute drive then feel each wheel as close to the hub as you can. See if one feels hotter than the others?

 

[Texxaco]

Are the brakes binding? Go for a ten minute drive then feel each wheel as close to the hub as you can. See if one feels hotter than the others?

That's what came into my head the minute I read new brakes and bad economy. Nothing else could really affect your economy if brakes is the only major change.

Trying jacking the van up and turning your front wheels whilst the van is not in gear, unless its a DSG i think.

If they don't turn easily your brakes could be binding.

 

[Scruffy]

Hi, yes thats my first job in the morning.

 

[Jason Stancliffe]

Hi , was it serviced at a vw garage?, they may have done a software update which could have affected your van

 

[Scruffy]

No, it was done at a local independent, I assume they don't have access to any software updates, but I will ask.

 

[Jason Stancliffe]

No, it was done at a local independent, I assume they don't have access to any software updates, but I will ask.

Ok, probably not that then, hope you get it sorted soon
Cheers
J

 

[Vinci]

Discs and pads just replaced at 40000 service....apparantly something to do with the stability stuff pulses the brakes, increasing wear?

 

[Big Al]

You can turn that ` massaging` thing off with VCDS. I`ll stick with centrifugal force to dry mine off.

 

[Scruffy]

?????

 

[Ukfozzybear]

You can turn that ` massaging` thing off with VCDS. I`ll stick with centrifugal force to dry mine off.

Is that a function of the esp or something else?

 

[Big Al]

I`ll guess your question??? Its to dry your brake discs off whilst your vehicle is in motion....... its like a shoulder rub for your discs .......

 

[Scruffy]

I've got to say I've absolutely no idea what you are talking about. Mine's a 16 plate Kombi, I wasn't aware it had any of these functions.

 

[Big Al]

Fair enough... I`ll get me coat.......

 

[Keeff]

Have you checked the oil level if is to high the crank could be dropping into it .

 

[Scruffy]

Have you checked the oil level if is to high the crank could be dropping into it .

Thanks, I'll get the garage to check that as well, its booked in tomorrow. I'd check it myself, but my drive is on a slope as is the lane we live on.

 

[Scruffy]

Well, it was back in the garage today, brakes are fine but a fault code came up, possibly an air flow meter/ sensor. Big job?

 

[Spaghetti]

There is an airflow meter on the pipe from the air cleaner to the turbo. Quick to change if it’s that one, but a few ££

 

[DaveD]

Well, it was back in the garage today, brakes are fine but a fault code came up, possibly an air flow meter/ sensor. Big job?

The MAF sensor is a 5 minute job to change, and a defective MAF sensor can cause poor economy.
I'm not sure how it would go defective because of a service though.

 

[Scruffy]

I'll give the garage the benefit of doubt and say it was just coincidence.