Thirsty Edition 30

[46Jason]

Hello all,
My stock edition 30 has a drinking problem. With a sensible light foot on a motorway run I still only get 20-21mpg. (250miles / tank)
She is DSG, non smoker and has been around a bit (114000miles), but no rattles /knocking from under the hood.
Just had the cam belt done - hoping this is not another expensive treat for me tired girl...any ideas?
Cheers
Jase

[BPGTI]

I've always heard Edition 30's where pretty thirsty! Maybe too obvious but sticking rear caliper?

[46Jason]

Hi there,
Rear calipers done last year (new pistons and seals- not a bad job).
The thirstiness is one of those things - I replaced the front shocks myself and paid for someone to replace water pump and inspect AC system (the gas escaped last summer(thought I had a puncture) and I thought it was a broken pipe). they informed me it is the compressor.
I thought maybe I or the garage had dislodged something resulting in thirstiness.
Thanks for the comment
Jase

[Jons1001]

Hi there,
Rear calipers done last year (new pistons and seals- not a bad job).
The thirstiness is one of those things - I replaced the front shocks myself and paid for someone to replace water pump and inspect AC system (the gas escaped last summer(thought I had a puncture) and I thought it was a broken pipe). they informed me it is the compressor.
I thought maybe I or the garage had dislodged something resulting in thirstiness.
Thanks for the comment
Jase

Hopefully someone a lot more knowledgeable than i am will be along soon to tell you how to diagnose this, suspect you might need interpret some live data to see what's going on, have you got any software?

[46Jason]

Hello Jons101,
I have a cheap OBDII reader - i have no dashboard warnings showing.... maybe she's like me and the lockdown has increased the drinking ability!

[J30SBO]

I have an edition 30, general comuting which is very short journeys etc I only get around 240 miles to a tank of 99. But then it is revo stage 1 mapped.. that being said I can usually get nearly 40mpg if I really really try on a long journey!

[owheel]

A quick way to check if it's a sticking caliper is to go for a drive where you can get up some speed, and then feel the wheels to see if one is hotter than the other.

The ideal drive would be an A road or a motorway junction, where you aren't doing a lot of braking. This means that the temperature difference between the sticking and non sticking calipers would be most pronounced.

I know this because I have had this exact issue recently...

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[46Jason]

Hello owheel,
I bought new pistons and kit from 'brakeparts.co' and done both rears last year. The only hiccup was get the old pistons out (pump on adjustment till fully out them a slug of air done the trick. the new kit was pretty good - the only 'issue' is the recess on pistons to 'wind back' are different to standard - a git of faffing with the rewind tool was required.
Rear bearings also replaced - 1 side had got 'slightly warm' and pumped out all the grease!
Cheers for the steer though
Jase

[owheel]

Fair enough! Well one that recently got stuck on for me was the front, and it wasn't noticeable while driving but it did make an mpg difference and the front wheel was significantly hotter than the other wheels. Might be worth a quick check as its super simple to do.

If it's an engine issue, I'm really not sure! I have a standard gti, and as someone said above if I'm disciplined I can hit high 30s to 40mpg on the motorway

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[fakie1977]

A stuck/broken thermostat can also cause reduced mpg (it did for me). Is your engine getting up to temp?


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[46Jason]

Hello - good call on thermostat - it has been a bit sticky recently so 'ill swap it out. Ill let you know if it improves
Jase

[colesey]

Pcv and dirty injectors are two other potential causes. How’s the oil consumption and idling?

[46Jason]

Hello Colesey,
No noticeable change on oil consumption. The idling is smooth. I have noticed erratic jumps in temp and cooling fans roaring away - my main problem is I have 3 different issues which make fault finding tricky and because I and a garage have played in the last month it could be anything....
Main issue at the mo are:
1) AC - I thought a pipe had broken (gas escaped all in one period -I thought I had a puncture until traced - didn't want to stick my head in to source leak. My friendly garage has chased it to the compressor - it has been refilled with gas and ' vacuum was good'. The garage explained that this is likely to be compressor clutch (no drive to compressor = no movement = no gas loss)...the biggy is that I cannot safely remove gas so need a grown up to purge / replace.
2) the 'clunk'. I replaced the front shocks recently. My garage done the cam belt / pump/ AC charge.Since the garage 'played' I have a low speed turning 'clunk'. Nothing is loose, new lower pinch bolts (couldn't believe the wear!), new ball joints. Drive shaft (long one|) replaced about a year ago...I don't think its the DSG - all gear changes are sweet and clunk is 1st gear wheel turning issue... Maybe damaged steering pump?
3) The thirstiness - the original exhaust has started blowing at the rear too so maybe a culmination of many niggles....
She the edition 30 and I've owned her for 6 years putting a good 60000 miles on her. I'm keen to do the work myself and can justify the hours - I just need to keep hiding the 'new parts' cost hidden....
Any pointers greatly received
Cheers
Jase

[fakie1977]

Could the “clunk” be front wheel bearings? This could also lead to higher fuel consumption


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[pudding]

My Stage 1 Revo'd Edition 30 long term average is 28mpg.  150K miles on the old girl.

For context......80 mile daily round trip.  Driven hard from cold, average motorway cruise of 85-90mph.  Yes I know, I'm naughty.  Regular boosting up to 100+ to blast past morons.

If I absolutely baby the gas pedal and never exceed 70mph, the best I can get out of it is mid 30s, but that's just too boring and schitt. Who buys a GTI to hyper mile?

So in a nutshell.....21mpg is uber shat.  I would be hitting her up with the scan tool.

Pop a plug or two out and see if they're all black and unhappy.  Should be a nice light grey/tan colour when she's all good in the hood.

If nothing obvious comes to light with the engine inspection, dragging brakes is indeed an old classic.  Does the car like to roll backwards/forwards very easily on slight inclines?  Is the brake pedal firm or spongey?