MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: bigkenny1781 on July 08, 2011, 08:32:26 am

Title: Diverter Valve
Post by: bigkenny1781 on July 08, 2011, 08:32:26 am
Hi,

Just a quick question for you lot - how can I check if my diverter valve is past it's best - the car goes okay, but not like a rocket and the economy is okay, but nowhere near what the manufacturer claims ...

I'm thinking it could be the diverter?!?!
Title: Re: Diverter Valve
Post by: TonyZed on July 08, 2011, 09:43:20 am
Hi Mate

I'm replacing mine over the weekend, so I might be able to tell you Monday if my symptoms are the cause of a duff DV.

Apart from what you describe, lack of performance and poor fuel economy, I can hear a continual whistle after the initial whoosh that you normaly get. Wind your window down and have a listen as you release the accelerator. Keep your foot slightly on the gas and you might get the same as me.

The only other way is to take it off and have a look, there are plenty of post on here that show you what to expect.

TonyZ
Title: Re: Diverter Valve
Post by: vRStu on July 08, 2011, 09:58:55 am
It's quite a simple job to whip it out and inspect it.  If you have VCDS then often you'll see a fault code stored.
Title: Re: Diverter Valve
Post by: GNJ_Motorsport on July 08, 2011, 05:16:15 pm
They do go quite often, particularly on mapped cars.
Title: Re: Diverter Valve
Post by: TonyZed on July 10, 2011, 08:34:12 pm
It's quite a simple job to whip it out and inspect it.  If you have VCDS then often you'll see a fault code stored.

Stu, I'm not sure what you were "whipping out and inspecting," but I'll have to remember next time a youngster like yourself says it is a simple job, I should remember my age (and size!)

Well I thought I'd try anyway!! :happy2:

It started badly for me when the wheel decided to be stubborn, and not come off as easily as it should, and I have had over 40 years of practice so it's not a new experience for me.
However, having managed that, I removed the inner wing lining, and then struggled for some time to remove the old DV. I do have some reasonable kit, including a socket set with cv joint type extensions. I couldn't get enough purchase with even my best alan keys to loosen the bolts, so without the socket set and attachments it would have been impossible. You do have to be a bit of a contortionist for sure.

At first it looked ok:

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi866.photobucket.com%2Falbums%2Fab225%2FTonyzed%2FIMG_0985.jpg&hash=a0b011208a8f6f2bb8ac7cb1f5f6f0778655f95e)

But then I looked closer

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi866.photobucket.com%2Falbums%2Fab225%2FTonyzed%2FIMG_0988.jpg&hash=af2861d2257918bc8758027e8014d4fba86aa1a1)

Though black marks around the diaphragm look like the beginnings of more splits too.

Anyway, after much cursing, and lots of skinned knuckles, I finally got it all back together and went for a test run.

 :jumpmove: :jumpmove: :jumpmove: is all I can say, it's so good to have my boost back.

So to the OP, if you can hear  a whistle continuing after the whoosh when you ease of a bit from hard throttle, then your DV is probably shot.

TonyZ

Title: Re: Diverter Valve
Post by: baldwined30 on July 10, 2011, 09:10:14 pm
Really easy, remove engine cover, you may have to remove the OEM air box too, undo the diverter valve. You will need to pull the cover quite hard! The Valve is held in using T25 bolts!
Once you have it out it just un srews

Did this today for a check over funny enough!

Title: Re: Diverter Valve
Post by: bigkenny1781 on July 10, 2011, 10:49:03 pm
I must have a look at the valve .... I drove the car for a while today and couldn't help thinking it felt slow.  Off the line through the gears it was quick-ish, but in-gear felt poor, no quicker than a 1.8 T Mkiv.  I've not driven another 5 Gti so it's hard to tell, but have driven loads of Astra VXR's and although they have 40ps or so more, they feel a different league to the GTi.  It just feels pedestrian - plant your foot down at 40 in 3rd (it's DSG) and it accelerates ... but not that quickly.  I can hear the turbo spool up, but it doesn't really pull hard at all.
Title: Re: Diverter Valve
Post by: Black9 on July 16, 2011, 11:54:57 pm
Without removing the DV is a whistle the only way to really know whether it's past it's best? Will there be a big drop in performance if it is?
Title: Re: Diverter Valve
Post by: baldwined30 on July 23, 2011, 12:26:06 pm
Not sure about the loss in power but its a real easy piece to remove and check! defo worth a look even just to eliminate this as a problem.
Title: Re: Diverter Valve
Post by: PND on July 23, 2011, 12:46:48 pm
Not sure about the loss in power but its a real easy piece to remove and check! defo worth a look even just to eliminate this as a problem.

Easy if you've got an Ed30!  Bit more involved for standard GTI owners.. which is why I've not got round to doing it yet! :laugh:
Title: Re: Diverter Valve
Post by: baldwined30 on July 23, 2011, 12:49:08 pm
Not sure about the loss in power but its a real easy piece to remove and check! defo worth a look even just to eliminate this as a problem.

Easy if you've got an Ed30!  Bit more involved for standard GTI owners.. which is why I've not got round to doing it yet! :laugh:
Sorry mate, didnt realise!