Heavy fuel consumption Golf GTI Mk4 1.8T

**MrGolf123** · 21-11-2007,03:16 PM

Nope - don't think I can do private messages. I'd really appreciate your feedback anyway, before I go back to the place I've been taking it to before.

Anytime on Saturday is fine - do you want to send me address info?

Thanks

**nick5golfs** · 21-11-2007,04:43 PM

Just to confirm what the others have said re fuel economy. I have had 5 Turbos and all did 25 odd in town and 35 odd on motorway. Less if a drove them fast.

Only time it was bad was when a lambda probe went but your engine managemnet light should come on if that happens.

Cheers

**MrGolf123** · 21-11-2007,05:12 PM

Thanks for your feedback Nick - I'm beginning to feel like my Golf used to be hydro-power or something! I swear that when I got it in May I was getting 37/38 mpg when doing 80/85 on the motorway and no less than 30/32 around town? Maybe I'm imagining things - however its giving a fault code still? very confusing and frustrating.

**Aaron-Golf** · 30-11-2007,08:05 PM

Hi guys,

Im also havin Very Low fuel consumption, 18-23mpg around town. its due a service which is booked in for 18th dec but been told the it wont make too much diff but a little none the less. I only got the car two weeks ago but its been mentioned abt the cat convertor might need replacing, will this make any diff??

Thanks in advance

ps my car is a gti 2.0 115 bhp.

**Crasher** · 03-12-2007,01:07 PM

Cats on the 2.0L only fail due to other common problems on that engine such as air leaks, AMM, leads, plugs, coil pack and lambda sensor.

**MrGolf123** · 06-12-2007,02:13 PM

Crasher, I've done this not - had the diverter value replaced with a VAG one as per the code you gave me but theres still no improvement, I did ask them to clean the throttle body as you said but looking at what they charged me £50 inc VAT) I dare say they didn't.

Any more ideas? - still the same problem, heavy on fuel and just a bit lacking on power. Also, can I just ask, at what RPM in the turbo supposed to start? I'm sure i can hear/feel mine at around 1500 rpm?

**Crasher** · 06-12-2007,02:50 PM

OK, let’s start at the beginning as this thread is jumping around a bit. What year and engine code and are there any fault codes stored? Has it been re-mapped? £50 is a little cheap for a throttle body clean and reset but only by a few pounds.

**MrGolf123** · 06-12-2007,03:39 PM

Its a 51 plate 1.8T Standard 150bhp - engine code is AUM. It was coming up with a fault code of "P1200 - Exhaust supercharger air circulation valve" - which you said sounded like either the throttle body or the diverter valve. I've changed the diverter valve - I gave them the code for that (06A 145 710 A) which you gave me and told them to clean the throttle body but like I said - £50 inc VAT for a new diverter valve fitted and a throttle body clean is too cheap isn't it?

Whats your take on the Turbo kick in question? I'm sure it starts at 1500rpm - is that right? I thought it should be 2000rpm when the turbo starts?

Thanks for your help by the way

**Crasher** · 06-12-2007,04:58 PM

OK, £50 all in is way too cheap, I charge £60 to remove and clean the TB with a reset after, never mind the valve at £25 plus clips and fitting. I messed up the part number for the valve it should be 06A 145 710 N but as 06A 145 710 A doesn’t exit, I imagine they fitted the right part. The turbo starting to spool up at 1500rpm sounds rather low and leads me to suspect a device known as the N75 valve which may be jammed closed and this would lead to over boost. Mine jammed open and under boosted. I feel that the TB will still need to be removed, cleaned and reset; I bet they didn’t appreciate how important the cleaning procedure is and just gave it a quick wipe out whilst still fitted and probably didn’t re-adapt it. Have you a decent VW specialist near you? If not, you may have to take it to VW for this.

**MrGolf123** · 06-12-2007,06:05 PM

Right, well i thought I had a good independent specialist near me (they've worked on a few of my friends Golfs/A3's but after spending £150 in diagnostics and £160 changing the Air Temp Sensor and AMM I'm starting to think that they're not as clue up as I thought. The Diverter Value and supposed clean of the TB was just done by a local guy who I know through my Dad, so that leads me to think he just wiped it as you said. Another question, sorry! Once he'd fitted the new Diverter Value - did he need to reset/readapt anything or is it just a case of stick it on and away you go?