Haldex / rear drive - issues on 2018 Audi S3 (woe content)
Discussion
I have a 2018 S3 S-Tronic and although it drives very well overall I've never been convinced that it had proper working 4WD when compared to my previous cars. I had it inspected in the last few days because this is a common issue on S3 / Golf Rs of this era. As suspected (and despite new fluid earlier this year), the Haldex pump gauze was gunked-up.
Unfortunately, replacing the Haldex pump and doing the VCDS pump re-learn procedure doesn't seem to have improved things. I'm told that the rear transfer box is still getting insufficient oil flow. The garage is going to try a final flush of the system from the pump onwards in case the gunk has gotten that far, but otherwise they say the next step is a new rear transfer box at c.£5k fitted!
I'm obviously a bit unsettled at that prospect.
It certainly doesn't seem like great value compared to all the other things in my life and at that price I'd consider the alternatives. Sadly, the car is out of warranty.
I guess I'm just asking for any experience or opinions on this. One option is to have a second garage or Haldex specialist look at it, though I'm already racking up a fair bit of labour charges just getting this far.
Unfortunately, replacing the Haldex pump and doing the VCDS pump re-learn procedure doesn't seem to have improved things. I'm told that the rear transfer box is still getting insufficient oil flow. The garage is going to try a final flush of the system from the pump onwards in case the gunk has gotten that far, but otherwise they say the next step is a new rear transfer box at c.£5k fitted!
I'm obviously a bit unsettled at that prospect.
It certainly doesn't seem like great value compared to all the other things in my life and at that price I'd consider the alternatives. Sadly, the car is out of warranty.I guess I'm just asking for any experience or opinions on this. One option is to have a second garage or Haldex specialist look at it, though I'm already racking up a fair bit of labour charges just getting this far.
The Cardinal said:
I have a 2018 S3 S-Tronic and although it drives very well overall I've never been convinced that it had proper working 4WD when compared to my previous cars. I had it inspected in the last few days because this is a common issue on S3 / Golf Rs of this era. As suspected (and despite new fluid earlier this year), the Haldex pump gauze was gunked-up.
Unfortunately, replacing the Haldex pump and doing the VCDS pump re-learn procedure doesn't seem to have improved things. I'm told that the rear transfer box is still getting insufficient oil flow. The garage is going to try a final flush of the system from the pump onwards in case the gunk has gotten that far, but otherwise they say the next step is a new rear transfer box at c.£5k fitted!
I'm obviously a bit unsettled at that prospect. It certainly doesn't seem like great value compared to all the other things in my life and at that price I'd consider the alternatives. Sadly, the car is out of warranty.
I guess I'm just asking for any experience or opinions on this. One option is to have a second garage or Haldex specialist look at it, though I'm already racking up a fair bit of labour charges just getting this far.
What made you realise that it was a haldex issue? Wheelspins pulling away from junctions? Anything else. The S3 and R are very much FWD biased as I'm sure you know, and having a similar car from the era i'd be keen to know what the warning signs might be! Unfortunately, replacing the Haldex pump and doing the VCDS pump re-learn procedure doesn't seem to have improved things. I'm told that the rear transfer box is still getting insufficient oil flow. The garage is going to try a final flush of the system from the pump onwards in case the gunk has gotten that far, but otherwise they say the next step is a new rear transfer box at c.£5k fitted!
I'm obviously a bit unsettled at that prospect.
It certainly doesn't seem like great value compared to all the other things in my life and at that price I'd consider the alternatives. Sadly, the car is out of warranty.I guess I'm just asking for any experience or opinions on this. One option is to have a second garage or Haldex specialist look at it, though I'm already racking up a fair bit of labour charges just getting this far.
Your other option is to use WBAC in this buoyant SH market. Unless the fault is very obvious? But perhaps not great to pass the problem on to someone else.
Flashing TC light, loss of traction on acceleration in the wet and slipping on spirited starts is a very common set of symptoms for Haldex issues on these cars, albeit usually cured by replacing the pump and flushing the system. It's not obvious unless driven hard, which I don't do much of.
I'm annoyed because I otherwise like this particular car and bought it as a keeper. I will indeed consider all options.
I'm annoyed because I otherwise like this particular car and bought it as a keeper. I will indeed consider all options.
Has the work been done at a dealer? If not, maybe buy the All-In package then claim on the warranty - although they'll probably say there's nothing wrong.
How many miles are on it? I tried to get a VW dealer to remove the pump and clean the screen on wife's Tiguan and they looked at me as if I was mad.
How many miles are on it? I tried to get a VW dealer to remove the pump and clean the screen on wife's Tiguan and they looked at me as if I was mad.
It's currently with a trusted VAG indy - the car's out of warranty. 24k miles, just coming up to 3.5 years old!
Edited to add: the Audi warranty quote was around £8-900 p/a from memory. I wouldn't want to pay that sum and then find that they declined any claim as a pre-existing issue (which it could quite rightly be).
Edited to add: the Audi warranty quote was around £8-900 p/a from memory. I wouldn't want to pay that sum and then find that they declined any claim as a pre-existing issue (which it could quite rightly be).
Edited by The Cardinal on Thursday 16th September 21:45
The Cardinal said:
Flashing TC light, loss of traction on acceleration in the wet and slipping on spirited starts is a very common set of symptoms for Haldex issues on these cars, albeit usually cured by replacing the pump and flushing the system. It's not obvious unless driven hard, which I don't do much of.
I'm annoyed because I otherwise like this particular car and bought it as a keeper. I will indeed consider all options.
I've certainly seen the TC light flash quite a lot, usually in damp / wet conditions but haven't experienced the slipping on spirited starts other than often getting a rather brutal jolt when the rears kick in. I've not had any noticeable wheel spin in five years. Tyre choice (and condition) will also be a massive factor in any traction issues as I'm sure you will also know. I'd be interested to hear how you get on. Fingers crossed flushing out works.I'm annoyed because I otherwise like this particular car and bought it as a keeper. I will indeed consider all options.
The Cardinal said:
It's currently with a trusted VAG indy - the car's out of warranty. 24k miles, just coming up to 3.5 years old!
Edited to add: the Audi warranty quote was around £8-900 p/a from memory. I wouldn't want to pay that sum and then find that they declined any claim as a pre-existing issue (which it could quite rightly be).
The All In package is less than that for 2yrs. Bizarrely the Audi price is slightly lower than VW.Edited to add: the Audi warranty quote was around £8-900 p/a from memory. I wouldn't want to pay that sum and then find that they declined any claim as a pre-existing issue (which it could quite rightly be).
The car has to have a quick check first, but if it doesn't show a fault code then they wouldn't know.
I must add that I've no idea if this woud be fool-proof for your situation! In depth checks may show the Haldex had been worked on. They may refuse cover if they've no record of the Haldex fluid being changed (recommended at 3yrs).
Any sign of an oil leak or grinding noise from the bevel box? Is there any play in the prop shaft? Presumably feeds to pump already tested?
I've never seen one completely fail but there are (rare) known issues with it.
If the haldex pump is getting feed/power then control unit fuse is unlikely:
Guided fault finding would have taken them through this but ask just in case. I've never seen this but it apparently can happen.
The general fix is pretty clear cut:
This doesn't sound like your symptoms but there may be an ESP update available:
From my experience this is more noticeable in roll-on acceleration rather than at launch.
I've never seen one completely fail but there are (rare) known issues with it.
If the haldex pump is getting feed/power then control unit fuse is unlikely:
Guided fault finding would have taken them through this but ask just in case. I've never seen this but it apparently can happen.
The general fix is pretty clear cut:
This doesn't sound like your symptoms but there may be an ESP update available:
From my experience this is more noticeable in roll-on acceleration rather than at launch.
I guess this is a gen 5 Haldex? Have you seen this: https://www.haldexrepairs.co.uk/generation-5-halde...
One of the things it notes is that it's vital the pump learn process is done after the pump is replaced (although they're mainly having a go at dealers and I've found indies seem to have more of a clue, although you don't generally get to talk to technicians at a dealer).
One of the things it notes is that it's vital the pump learn process is done after the pump is replaced (although they're mainly having a go at dealers and I've found indies seem to have more of a clue, although you don't generally get to talk to technicians at a dealer).
Well, this tale took an unexpected turn and not one I've seen reported elsewhere online.
Firstly, a proper VCDS scan did show a fault code. I haven't checked which the code was, but it's not one that came up via my Carista app and that's worth noting in itself. The mechanic removed the original Haldex pump and found it to be working, though with shards of metal and gunk present. I guess this is what many other people are finding and, following a clean / new oil / reset this is usually enough to solve the issue.
[I should add that my Haldex oil was changed 2,500 miles ago by the same people...]
This might normally have been enough to restore satisfactory performance. However, in my case, there was another issue.
This second issue was a manufacturing defect in the Haldex unit itself - where several of the oil reservoir chambers were insufficiently machined and this meant that the unit was unable to create sufficient pressure. The mechanic's view was that this was present at the time of manufacture and that the rear drive had quite probably never worked from new.
The solution of shortening the drain plug to create more space for the oil flow. I was instructed to tell whoever does the next Haldex oil change to make the same adaptation to the drain plug. I'm a little confused about this and it seems slightly bodge-ish. Nonetheless, it's worked!
Finally, the Haldex pump was replaced as it was found to be underperforming - probably a legacy of the first issue.
Just... wow. The transformation of the driving experience is immense. I challenge anyone to drive one of these cars in the state mine was in and then not to notice a *massive* improvement. Even at very low speeds there's an huge difference, while on the open road / out of bends etc it's nothing short of breathtaking now that full torque is being put down by all 4 wheels. Now I know why I persisted in solving this and it reminds me how well-suited these VAG 4WD hatches can be for me and my preferences.
I drove the car for 5 months and 2,500 miles in its pre-fixed state. To think that the first owner probably drove 22,000 miles like that seems amazing to me.
I suppose the final bill was somewhat steeper than I'd like, caused by more investigate labour and two flushes of the Haldex fluid - but right now it seems worth it.
Firstly, a proper VCDS scan did show a fault code. I haven't checked which the code was, but it's not one that came up via my Carista app and that's worth noting in itself. The mechanic removed the original Haldex pump and found it to be working, though with shards of metal and gunk present. I guess this is what many other people are finding and, following a clean / new oil / reset this is usually enough to solve the issue.
[I should add that my Haldex oil was changed 2,500 miles ago by the same people...]
This might normally have been enough to restore satisfactory performance. However, in my case, there was another issue.
This second issue was a manufacturing defect in the Haldex unit itself - where several of the oil reservoir chambers were insufficiently machined and this meant that the unit was unable to create sufficient pressure. The mechanic's view was that this was present at the time of manufacture and that the rear drive had quite probably never worked from new.
The solution of shortening the drain plug to create more space for the oil flow. I was instructed to tell whoever does the next Haldex oil change to make the same adaptation to the drain plug. I'm a little confused about this and it seems slightly bodge-ish. Nonetheless, it's worked!
Finally, the Haldex pump was replaced as it was found to be underperforming - probably a legacy of the first issue.
Just... wow. The transformation of the driving experience is immense. I challenge anyone to drive one of these cars in the state mine was in and then not to notice a *massive* improvement. Even at very low speeds there's an huge difference, while on the open road / out of bends etc it's nothing short of breathtaking now that full torque is being put down by all 4 wheels. Now I know why I persisted in solving this and it reminds me how well-suited these VAG 4WD hatches can be for me and my preferences.
I drove the car for 5 months and 2,500 miles in its pre-fixed state. To think that the first owner probably drove 22,000 miles like that seems amazing to me.
I suppose the final bill was somewhat steeper than I'd like, caused by more investigate labour and two flushes of the Haldex fluid - but right now it seems worth it.
The Cardinal said:
I drove the car for 5 months and 2,500 miles in its pre-fixed state. To think that the first owner probably drove 22,000 miles like that seems amazing to me.
I guess if you don't know.... I took over a company car that someone had done 20000 miles in in 6 months (and it had been serviced) and it was instantly (like within a mile) obvious there was something seriously amiss. It still had the transit blocks in the suspension. Going around roundabouts it was hilarious - it just went sideways!If the garage is correct in their diagnosis I wonder if that's a one off, or if there's a whole bunch of incorrectly made Haldex's out there?
The only time it drives the same as before this fix is at high speeds. I can't detect an improvement accelerating at NSL-type speeds, so at least it was eventually getting the power down I guess.
But (as I think DrG sagely advised me in advance) in almost any other situation it's night and day. It even sounds angrier through the gears and the sense of torque at low speeds is now exactly what you'd expect of a car like this. Stunning.
But (as I think DrG sagely advised me in advance) in almost any other situation it's night and day. It even sounds angrier through the gears and the sense of torque at low speeds is now exactly what you'd expect of a car like this. Stunning.
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