How to Disable Haldex?

[RustyBucket]

I'm trying to diagnose a 'noise' coming from the rear of my 2006 8p S3. It's a kind of thrumming / whirring that becomes apparent at about 30mph and you can then hear it constantly after that although it doesn't really increase in volume and I'm not entirely sure if the thrumming increase in speed as the car does. I initially thought wheel bearing but I know what one failing sounds like and this is different so my next move is to disable the haldex and see if that makes a difference but I can't find any info on the best way to do this. Is there a fuse I can remove or do I unplug the haldex drive and if so how can I do that? As ever any help greatly appreciated. Thanks.

 

[Sayam]

There is deffo a fuse you can remove as some remappers do that if they have a 2WD dyno. Where that fuse is, unfortunately, I can't tell you.

 

[Rideen]

Should be fuse 31 where the rest of the fuses are.

 

[RustyBucket]

Thanks guys, I know that the guys at rtech just disconnect the pump for their dyno but I'll have a look a fuse 31 in the meantime. Cheers

 

[Dawud afzal]

Fuse remove it to make it 2wd

 

[RustyBucket]

I've been trying to locate the correct fuse to pull but slot 31 is a vacant slot on my car:



however on the inside of the fuse box cover it says that it should be the vacuum pump?



Referring to the manual, slot 31 is vacant:



But on the first page it say that slot 2 controls 4WD and a host of other components:



So I'm confused as to which fuse to pull, if I pull number 2 doesn't this also turn off a load of other stuff that would cause problems? An alternative I thought would be to pull the plug on the Haldex itself which must be easy but having looked on here and other forums a plug doesn't seem to be in the place I thought it would be., Do I need to remove the Haldex control and unclip the plug (s) on the back to that?



Any advice at this stage greatly appreciated
Cheers

 

[DomH]

If it's the plug that runs over the top to the Haldex pump it should do the job

 

[RustyBucket]

Thanks for that, I think it is but it looks like I'll havre to take the controller off first to get at the plug, any idea on what fuse it may be?
Cheers

 

[BennyG_UK]

Think the plug that runs over the passenger side fuel sender under the rear bench disables it too. Cant remember 100% but sure I've seen that mentioned before, never tried it though.

 

[S3 AEX]

Under the rear seats there's a connector, unplug that disable's the haldex

 

[RustyBucket]

Ah, fantastic, i'll have a look tomorrow......... I expect the next post will be 'how do I get the rear seat out' ;-)

 

[superkarl]

Fuse 31 is the haldex fuse for older 8L S3s.
Just pull the one your diagram says.
Alternatively, pull the handbrake up 1 notch and this will also disengage the haldex

 

[RustyBucket]

Thanks for the handbrake advise although I've read that this doesn't seem to work for the 8P, I'm also a bit nervous of pulling that fuse because of everything else that seems to be running off it.....

However, I've finally got round to lifting the rear seat and under the inspection hole (the one directly above the Haldex controller) is this. Is this what I can disconnect to disable the Haldex?



Cheers

 

[S3 AEX]

Thanks for the handbrake advise although I've read that this doesn't seem to work for the 8P, I'm also a bit nervous of pulling that fuse because of everything else that seems to be running off it.....

However, I've finally got round to lifting the rear seat and under the inspection hole (the one directly above the Haldex controller) is this. Is this what I can disconnect to disable the Haldex?

View attachment 66270

Cheers

Yes bud

 

[RustyBucket]

Excellent, thanks. Haldex disconnected and flooring it is quite a surprise Anyhow, the 'noise' is still there with it disconnected so I reckon the next step is another haldex oil change (only done about 5k ago) and is it possible to change the diff oil does anyone know?
Cheers

 

[Bazzle]

Yes . Diff has 2 hex plugs at the rear and bottom.
Always undo the top one ist in case its stuck or you wont be able to fill back up.
http://forums.vwvortex.com/showthre...rential-Oil.......NOT&highlight=rear+diff+diy

 

[RustyBucket]

Quick update, this turned out to be a wheel bearing.........not heard one worn like that before but you learn something new every day