S3 8L Haldex Issues - Driving like a solid rear diff!
- Thread starter Jas Lad
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My original diff was taken out inc its controller, swopped with 2nd hand diff and its controller, it was no better so i swopped it back to my original controller which made it worse, so with the change in behaviour im thinking its 2 duff controllers, I have a 110% working controller from an 01 4motion Golf to put in.
larsmate
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Best of luck!
My car was two wheel drive for around six months until I replaced the pre-charge pump. This fixed the problem however now I get some slight locking of the inside rear wheel when driving very slow and on full steering lock. Probably not the same problem as yours but leads me to wonder two things - as someone mentioned earlier - the diff and the haldex are seperate but do they share the same oil? I have no controller problem but get similar symptoms to you except it only happens when the car is cold.
My car was two wheel drive for around six months until I replaced the pre-charge pump. This fixed the problem however now I get some slight locking of the inside rear wheel when driving very slow and on full steering lock. Probably not the same problem as yours but leads me to wonder two things - as someone mentioned earlier - the diff and the haldex are seperate but do they share the same oil? I have no controller problem but get similar symptoms to you except it only happens when the car is cold.
Answer me this, did you loose much haldex oil when removing the precharge pump or would I need another tube?
not sure on the answer above, but bear in mind the majority of people who end up either replacing the diff or controller have never seen any errors show up on vagcom.....if only it was that straight-forward.
Also bear in mind there are so many cars with this problem (well, i think so - a lot don't even want to mention it and rather just sell them on) it's best to get one off an Audi TT with frontal damage. Strangely I've not heard many TT owners complain about this rear locking issue.
Also bear in mind there are so many cars with this problem (well, i think so - a lot don't even want to mention it and rather just sell them on) it's best to get one off an Audi TT with frontal damage. Strangely I've not heard many TT owners complain about this rear locking issue.
Ok another update.
Got the controller off the mk4 4motion fitted tonite.... drives exactly the same as my last controller did. So i'm ruleing out the controller being the problem.
All im left with now is to swop pumps from my old diff to this one and see if the behaviour changes. After that im out of ideas
Got the controller off the mk4 4motion fitted tonite.... drives exactly the same as my last controller did. So i'm ruleing out the controller being the problem.
All im left with now is to swop pumps from my old diff to this one and see if the behaviour changes. After that im out of ideas
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Well im going to swap over my haldex pre charge pump to see if this fixes it or changes its behaviour, if it does i'll get the one off the 4motion.
After that im calling it a day and selling it. I've spent hundreds.
After that im calling it a day and selling it. I've spent hundreds.
Just a thought but would it be my steering angle sensor? Perhaps the car doesnt know what the steering angle is and thus doesnt know when to turn the pump off?
Where is the sensor located at? VAGCOM shows the angle quite clearly correct so maybe not?
Where is the sensor located at? VAGCOM shows the angle quite clearly correct so maybe not?
beanoir
Large Member
I use AmD in Thurrock and they know what they are talking about. Ben is helpful there. There may be an AmD closer to you.
Plenty of others of course.
Plenty of others of course.
I have to say, one fairly unique difference with your problem is that when you try the handbrake trick of lifting it up one notch then you never have a problem- 99% all rear locking wheel issues I have read stated that the handbrake trick did not work for them.
Surely that must mean something to an expert and it's a fundamental point on where the problem is.
Surely that must mean something to an expert and it's a fundamental point on where the problem is.
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To me that means electrical, not mechanical. Means the handbrake switch works and haldex controller works, otherwise itd do nothing.
Steering angle sensor usually brings the esp light on.
What happens when you have the car jaxked up and you spin 1 wheel?
Lifting the handbrake one notch tell the haldex unit not to activate the electronic controller. So i'd assume electrical too as the Haldex is engaged when it shouldn't be
Without no thanks from any Audi specialists or mechanics I fixed it myself, swapped the precharge pump and done an oil change... et voila, working 4wd PERFECT, so happy!
PERFECT, so happy!
beanoir
Large Member
I know im so glad its sorted, original diff must have had a seized clutch plate, 2nd diff had a faulty precharge pump... so now iv a spare working controller to sell which should recoup some costs I guess..
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Yep it all sounded normal enough but on the diagnostics you could see the pump on a low load basis wasnt dropping from a hi state into the low which it should have..
which year, engine model is your car ?
your fix is a first I've heard (pre charge pump failure) for this kind of issue.
especially wierd when you couple the specific problems you were experiencing - so it doesn't quite make sense that was the issue.
your fix is a first I've heard (pre charge pump failure) for this kind of issue.
especially wierd when you couple the specific problems you were experiencing - so it doesn't quite make sense that was the issue.
Its a 2002 BAM... and the replacement diff apparently came out of one the same model.
