MK5 Golf GTI - Fuel Economy!!

[E8RNX]

@Chesto18 @muff1991

I’m so happy with all the help I receive of this forum! You guys are so helpful and always there   

Okay so tomorrow I’m gonna get car up and make sure there are no calipers sticking (that could definitely be a big one and one that I haven’t checked). I’ll also disconnect battery just so computers reset, I’m sure this hasn’t been done in a while.

About the PCV, yes when I pull out dipstick it gets super crazy rumbly  messed so I think that seems fine.

And yes defo aren’t any leaks! If I didn’t mention we have our own garage and MOT centre and cover every vehicle! I’ve made sure there definitely aren’t any leaks whatsoever :)

@muff1991 I’m based in Sheffield. I’m not familiar with how to use VCDS but know a few people who have it - so I just scan using VCDS? Currently I’ve been using my Snap-on diagnostics the latest one - it gives you live figures too.
Yes fuel is defo so bad right now 😤, hopefully I get to the bottom of it soon enough and will defo keep you guys updated

Once again thank you.

[akispap]

I've had almost all the above, I couldn't get more than 31-32mpg on 60-70 in motorways.
It turned out both my rear calipers were dragging me, also I knew my thermostat was gone,
and I had a clean in my inlet and injectors and remap. Now I see easy 37-38mpg on the same speed.
I'm thinking of changing the MAF as well and fuel filter to see if I can get it 40ish!

[muff1991]

@Chesto18 @muff1991

I’m so happy with all the help I receive of this forum! You guys are so helpful and always there   

Okay so tomorrow I’m gonna get car up and make sure there are no calipers sticking (that could definitely be a big one and one that I haven’t checked). I’ll also disconnect battery just so computers reset, I’m sure this hasn’t been done in a while.

About the PCV, yes when I pull out dipstick it gets super crazy rumbly  messed so I think that seems fine.

And yes defo aren’t any leaks! If I didn’t mention we have our own garage and MOT centre and cover every vehicle! I’ve made sure there definitely aren’t any leaks whatsoever :)

@muff1991 I’m based in Sheffield. I’m not familiar with how to use VCDS but know a few people who have it - so I just scan using VCDS? Currently I’ve been using my Snap-on diagnostics the latest one - it gives you live figures too.
Yes fuel is defo so bad right now 😤, hopefully I get to the bottom of it soon enough and will defo keep you guys updated

Once again thank you.

its nice to see people pull together and throw ideas about the place.. all helps in aid to fix other peoples problems!

I asked if you had VCDS as you could check for misfires etc and also to see where you was based, because if you haven't got it ive just acquired it and would assist If I was closer to you.

did you manage the get the car jacked up and check the rear wheels free spin? (sticking calipers) ?

[E8RNX]

@muff1991

Hope your well. Yes I did jack the car up, no Calipers sticking. To make sure I also got it on brake rollers and came out even, no sticking.

Also checked using VCDS, no suspicious looking faults came out.


Today I have ordered a PCV valve and gasket, will fit it in today and give you an update later tonight hopefully.

Regards :)

[muff1991]

I'm well thanks. at least you've now ruled out the calipers :)

give PCV a go but I wouldn't hold your hopes up massively on that one as yours sounds ok.

other than what's already been covered, I'm virtually lost for ideas lol

[E8RNX]

IKR, honestly lol 😳😂

Everything has been ruled out, I couldn’t think what else it could be.

So now I’ve changed the PCV, on the way back home just by looking at trip computer I saw 20 MPG (I have never seen this before lol). I was driving very calmly little to no throttle. Don’t know whether it’s improved yet, guess I’ll have to drive for a while and report back. But saying that even whilst driving calmly on the trip computer I’ve only seen figures max around 15 MPG odd. Don’t know how accurate the computer figures are for you guys but generally speaking after calculating myself they are more or less on point with MPG figures.

I also last week put in a full tank with Fortes Fuel System flush which is meant to be quite good so hopefully injectors should get clean.

[muff1991]

sounds promising..  fingers crossed, that could be it.. and if not fully at least its better than what it was!

see how the next tank of fuel goes and go from there

[Chesto18]

If it was me I’d now be checking all the fuel line from start to finish. LPFP, filter, HPFP, Injectors, making sure all are working as they should. The fuel is going somewhere!

Are you sure the computer is accurate?

When was your cam follower last changed out of interest?

[E8RNX]

@Chesto18

When I get a chance that's a great idea to check all fuel lines thank you. Cam follower was changed about two weeks ago along with service + fuel flush.

Tbh with you since I've changed MAF, DV, PCV i have seen a HUGE improvement of fuel economy without mentioning performance. Im obviously not looking for high fuel economy from a Golf GTI but I definitely want what I'm meant to get at least lol. But yeah I've 100% seen a big improvement.. guess ill just keep driving and see how it goes!

There are some guys on this forum who get MAD MPG figures for a GTI 

[E8RNX]

Oh yeah and I'm not sure how accurate trip computer is - I don't trust it as it changes figures all the time.

BUT!

The miles remaining on the fuel screen on the highline MFD today as I drove to work was showing 200+ WHICH IS AMAZING  lol.

Previously, may I add it showed like 120-160 for a full tank haha.

Definitely improved... once I've ran a few full tanks ill calculate what MPG I'm getting and let you know.

[muff1991]

defo an improvement then.. hopefully things get better when the ECU adapts to the new bits and the dash starts showing better figures as time goes on :)

[E8RNX]

Hi guys so here’s an update on my fuel economy for the GTI!:

I am getting perfect and the correct fuel economy now, after driving for a while, changing a number of parts it has totally improved from what it was. I went on a long run recently - mostly motorway driving and got 400 miles to the tank!!!!!!!!!!
That was an average of around 30MPG and yeah like I said that was long distance driving - using cruise control on 70MPH then a bit of city too ( and if I say I also floored it a quite a few times too).

Previously what I was getting was ridiculous so here’s what I changed and did from the advice of all the forum members who helped and quite a bit of my own diagnostics using VAG COM and a snap on device. :

- Replaced MAF Sensor
- New DV
- New PCV
- Computer reset by disconnecting battery
- New temperature sensor
- Fuel system flush

So yeah thanks for all the help guys, wish you all the best.

[muff1991]

really happy its all worked out for you mate and you're now enjoying the car! 

[PKGTI]

50 mile A road cruise in light traffic yesterday keeping to 70mph I achieved an indicated 39.3 mpg!!

 

[Chesto18]

Hi guys so here’s an update on my fuel economy for the GTI!:

I am getting perfect and the correct fuel economy now, after driving for a while, changing a number of parts it has totally improved from what it was. I went on a long run recently - mostly motorway driving and got 400 miles to the tank!!!!!!!!!!
That was an average of around 30MPG and yeah like I said that was long distance driving - using cruise control on 70MPH then a bit of city too ( and if I say I also floored it a quite a few times too).

Previously what I was getting was ridiculous so here’s what I changed and did from the advice of all the forum members who helped and quite a bit of my own diagnostics using VAG COM and a snap on device. :

- Replaced MAF Sensor
- New DV
- New PCV
- Computer reset by disconnecting battery
- New temperature sensor
- Fuel system flush

So yeah thanks for all the help guys, wish you all the best.

Awesome, well done for bottoming it out. So rather than one big issue causing it, it was a combination of parts needing to be renewed. A simple service can work wonders.

I didn’t catch whether you’d changed the air and fuel filter but these are both well worth changing also.