2008 Golf GTI Ed30 - Sluggish in low revs, very (very!) low MPG

[SyntaxTerror]

Hey All,

So my Ed30 hasn't quite been the same since its recent Major service (a few months back).
Currently, i am averaging 22mpg on my journey to/from work, which is 25 miles, but mostly urban. This is a definite contrast to the 27/29 i have been used to!
Also, from low revs the car feels weak, and rev-up is a little jittery (but only just noticeably so). Power also feels reduced in mid to high revs, and the activation of the turbo at the 2500rpm mark feels a lot more pronounced than it ever has before.

Checking for engine fault codes with VAG-COM shows no issues!!

I am expecting this to be a PCV failure, possibly also a MAF failure. However, doing the recommended PCV check of removing the dipstick while the engine is running causes the idle to become rougher slightly, then return to its normal idle (along with a whooshing sound of the air escaping) which implies to me that this isn't the problem!?

I'm about to book it in with the stealers who performed the major service, just wondering if anyone had any thoughts on the above, or could let me know something else i can test using VAG-COM that might let me know what the issues are before i take it in.

ta :)

edit: also, completely standard setup, no mods!

[flyboy1976]

Diverter valve perhaps...easily checked

[SyntaxTerror]

Thanks mate, had the DV fail a couple of months before the major service, and it was replaced with the latest rev.
As far as i can tell, it's still in action. Still clearly hearing the familiar PSSHHT on dump, and turbo spooling noise. Will check it though!

[flyboy1976]

Have you looked at the plugs and what is the mileage of the car? when were they last changed? You said it has had a service recently....has the problem surfaced since that event...if so what work was carried out? also has it got the latest revision of coil packs installed as they were a recall from VW FOC so if you are unsure then go to you nearest dealer and ask if it has been done (if not get them to do it)
The latest revision of coil packs are 'F's' iirc and the (replaced) diverter valve should be either a 06H revision 'C' or 'D' or even a 06F revision 'G' (if you look on the side of the diveter valve you will see the full part number, note it down and get back to me)
PCV could be an issue and aren't too much money to change, the last revision i last heard of was an 'N' but ask someone on here who has access to ETKA to confirm.

[flyboy1976]

http://www.golfmkv.com/forums/showthread.php?t=24952

[SyntaxTerror]

Thanks Flyboy!

Mileage is 36k. Not looked at the plugs, but they weren't changed during the major service. Did fit a new Cam-Belt and Water pump. As for the coil packs, i think the 2008 model was later than the RMA if my memory serves me correctly (anyone know this)?

After the service i did notice some oddities with the car, the revs didn't feel quite as smooth as before, but overall the car felt ok. The issues i've been having have slowly increased since the service, it hasn't ever felt 'perfect' since having the work done.

Thanks for the heads up on revisions. Currently its absolutely crapping it down outside so i can't really go and check :/ wish i had a garage :( However, I've fished out the parts list from the DV change, and it's the revision G: 06F145710G

I'm going to request that the PCV is changed, even if they don't find fault with it, as the latest rev rumoured to be significantly tougher.

I'm booking it in for next week, so any pearls of wisdom are still much appreciated!

Thanks again

[flyboy1976]

Get VW to check and see if the have bashed the N75 valve on the turbo when doing the cambelt.
I would get the plugs swapped out ASAP fella (unless the car is mapped just go with the OEM ones) as i bet they are the originals in the car and at 36K they have seen better days. what fuel do you run the car on....i use tesco momentum 99 or shell optimax....always put decent fuel in buddy. Another thing is to change the fuel filter, now here is the thing....fuel filter change is not part of ANY part of a VW service schedule at all on this vehicle. Check the diverter valve anyhow for splits...its just three trx bolts and an electrical plug. Any further help just shout me!

[DSG-GTI]

Did you have the cam belt changed... if so It sounds like they have got the cam timing wrong !!! it seems to happen quite a lot...

[SyntaxTerror]

Thanks gents,

I always fill her up with v-power , (used to make) a noticeable difference to mpg.

Also found the Major service doc and the plugs HAVE been changed! (so, possibly bad ones)

When i spoke to Allan Day (the original servicers) they've told me:
"We can't do anything unless its throwing a fault code"
Great service, thanks guys!

So, yesterday i contacted TuningWerkes and got a response from Reuben saying he will take a look, i've heard good things about them. i've been wanting the APR flash for quite some time, just wanted the car to be perfect again first!
I'll point him to this thread, he might want to leave some feedback.

Thanks again for all the suggestions

[DSG-GTI]

If it was dropping a plug it would show up in the diagnostics wouldn't it ... I run mine on all different fuel and it never misfires ... just goes better on the V power  I would still like to bet the cam timing is a couple of teeth out... I would take it to a good tuning place and get them to check it ... wouldn't be the first time a dealer has got it wrong !!! might be wrong but it may save you a lot of time and money not to mention the stress in the long run. Good luck bud and let us know how you get on 

[alackofspeed]

Another vote for the timing belt. Crops up far more often than it shoud on here - seems a surprising number of garages can't get the very simple job done properly! Good job there are only two toothed wheels to line up on a TFSI.... imagine the errors a garage could make with 5!

[DSG-GTI]

I wouldn't take my single cylinder OHC lawnmower to my local dealer.... Trouble is my belt is due in October and as I have warranty with VW Im going to have to take it to the dealer I bought it off (not my local one) but Shrewsbury VW .... so far these guys seem ok ... I had the air con compressor fail and they sorted it with no hassle so fingers crossed they get it right.... plus maybe a word in the "fitters" ear telling him I built CAT engines for years... so get the effing belt right... that should do the trick     plus I will be driving it up the road before I pay the bill... oooops rant over now... it just annoys me that people pay good money then get a load of hassle getting a problem put right that wasn't there in the first place. Anyway like I said to the OP let us know how you get on.

Sorry for the rant and hi-jack   

[56OctyVRS]

I wouldn't take my single cylinder OHC lawnmower to my local dealer.... Trouble is my belt is due in October and as I have warranty with VW Im going to have to take it to the dealer I bought it off (not my local one) but Shrewsbury VW .... so far these guys seem ok ... I had the air con compressor fail and they sorted it with no hassle so fingers crossed they get it right.... plus maybe a word in the "fitters" ear telling him I built CAT engines for years... so get the effing belt right... that should do the trick     plus I will be driving it up the road before I pay the bill... oooops rant over now... it just annoys me that people pay good money then get a load of hassle getting a problem put right that wasn't there in the first place. Anyway like I said to the OP let us know how you get on.

Sorry for the rant and hi-jack    

As long as you take it to a garage that uses Genuine VAG parts your warranty is still valid. You dont have to use main stealers anymore to keep your warranty.

My bet is that they are a tooth out on the belt and the timing is wrong or the tensioner is not correctly set up and has let the belt jump.  Makes you wonder if they actually manually spin the engine round to check once the belt is fitted and double check then triple check its all okay.

[DSG-GTI]

I wouldn't take my single cylinder OHC lawnmower to my local dealer.... Trouble is my belt is due in October and as I have warranty with VW Im going to have to take it to the dealer I bought it off (not my local one) but Shrewsbury VW .... so far these guys seem ok ... I had the air con compressor fail and they sorted it with no hassle so fingers crossed they get it right.... plus maybe a word in the "fitters" ear telling him I built CAT engines for years... so get the effing belt right... that should do the trick     plus I will be driving it up the road before I pay the bill... oooops rant over now... it just annoys me that people pay good money then get a load of hassle getting a problem put right that wasn't there in the first place. Anyway like I said to the OP let us know how you get on.

Sorry for the rant and hi-jack    

As long as you take it to a garage that uses Genuine VAG parts your warranty is still valid. You dont have to use main stealers anymore to keep your warranty.

My bet is that they are a tooth out on the belt and the timing is wrong or the tensioner is not correctly set up and has let the belt jump.  Makes you wonder if they actually manually spin the engine round to check once the belt is fitted and double check then triple check its all okay.

Really ... must look into that  


My previous car was a Mk4 GTI diesel 150 had it 8 years and used a local fella to do services and the cam belt .... come to think of it that's all it ever had done... other than brakes/discs/air con gas... great motor... fella has been in the trade for years and knows his stuff so I would much rather him do it, Must give him a bell thanks for the info.
I would bet it's the inlet cam that's out .... tensioner side 

[Frodo-anni]

Did you have the cam belt changed... if so It sounds like they have got the cam timing wrong !!! it seems to happen quite a lot...

Would a cambelt timing being out cause any damage other than just poor performance?