How to spot bad haldex system?

[Slava]

Hi all!

Just signed up to this forum. I was test driving a used car which I am planning to buy. It is 2015 Audi S3 Prestige model with 42700 miles. I have read few forums about haldex problems and want to find out how a normally working haldex behaves vs a bad one.

I did a hard launch(not launch control) from the stop on dry asphalt. Below are 3 tests:

First try: The front tires spun for 2 or 3 sec and then I felt the rear wheels kick in and car took off nicely.
Second try: Did another launch, but this time with traction control OFF and front tires spun a bit(1 sec) and car took off!
Third try: Launch again, but with traction control ON and front tires spun a bit and car took off!

So looking at the first launch, the tires spun longer before car took off. This car was on the lot for a few months and possibly haldex wasn't engaged for some time and after first try it started working?
OR
It this normal behavior on S3 or it doesn’t sound right and there is a possibility of Haldex system that might be bad?

Basically I want to make sure I don't buy a car with an issue as the manufacturer's warranty had expired

 

[Beery]

The first try sounds a little long for it to kick in to me...The haldex does take a moment or so to kick in under normal conditions but on mine its usually a fraction of a second. I believe (I may be corrected) that in dynamic mode it puts more power to the rear under normal conditions.

On mine...my haldex is fine but the filter was pretty clogged and it would even spin in 2nd gear...oil change and filter cleaned and its back to normal. Could just use it as a bit of a bargaining reason and just get the filter cleaned out - Audi don't do this as part of the normal servicing, they just change the oil. Also the pump will usually go first if its clogged up before the haldex itself...the pump isn't hugely expensive.

 

[Slava]

The first try sounds a little long for it to kick in to me...The haldex does take a moment or so to kick in under normal conditions but on mine its usually a fraction of a second. I believe (I may be corrected) that in dynamic mode it puts more power to the rear under normal conditions.

On mine...my haldex is fine but the filter was pretty clogged and it would even spin in 2nd gear...oil change and filter cleaned and its back to normal. Could just use it as a bit of a bargaining reason and just get the filter cleaned out - Audi don't do this as part of the normal servicing, they just change the oil. Also the pump will usually go first if its clogged up before the haldex itself...the pump isn't hugely expensive.

Interesting, so if the first try sounds a bit long for haldex to kick in, could it be then the car was stationary for a few months and haldex just came to life again after that first try?
I can check with Audi about cleaning haldex(oil and filter change) and find out the price.

There are 2 cars that I am considering, the 2015 S3 Prestige I was referring to and 2017 A4 Premium with only 21500 miles on it with over 2 years of factory warranty left. Both cars are fine to me. I never had an Audi, so which one would you recommend for a piece of mind?

 

[Dannymoto]

Audi won't clean the filter, they only change the oil. You're best off taking it to an Independent garage. Should be around £75-£100 depending where you go.

The tyres don't spin on my S3 at all unless I'm turning out of a junction with full lock and plant my foot then it takes a second or two to kick in.

 

[Terminator x]

Audi won't clean the filter, they only change the oil. You're best off taking it to an Independent garage. Should be around £75-£100 depending where you go.

The tyres don't spin on my S3 at all unless I'm turning out of a junction with full lock and plant my foot then it takes a second or two to kick in.

When mine was done I specifically asked Audi to change the filter as I'd heard they just leave it alone! The part is peanuts so **** knows why they don't just change it out.

TX.

Sent from my BBB100-2 using Tapatalk

 

[Slava]

Audi won't clean the filter, they only change the oil. You're best off taking it to an Independent garage. Should be around £75-£100 depending where you go.

The tyres don't spin on my S3 at all unless I'm turning out of a junction with full lock and plant my foot then it takes a second or two to kick in.

I see. In my case it was a straight line.

 

[Dannymoto]

I see. In my case it was a straight line.

Never had any problems with spinning wheels in a straight line, might be worth trying it in launch control. The haldex pumps are prone to failing due to the build up of gunk, if it has failed then if it’s under warranty then they will replace it as there is a TPI out for it. If not then you can buy a brand new from HaldexRepairs for £200.


Sent from my iPhone using Tapatalk

 

[HertS3]

My car (2014 with 44k miles) used to do this 'juddering' for a few seconds then launch and the computer did actually show a failed Haldex pump, and also when it was icy I got stuck on an uphill start and have to reverse down and get a rolling start to get over the hill which apparently shouldn't happen. However, I had the oil changed and filter cleaned and computer reset, since then I believe that the car is working fine. I've not had any wheel spin, so I can only conclude that the Haldex had issues (as the filter had never been cleaned up to 44k miles/3.5 years) and flagged the pump as faulty, however once the system was cleaned out, the car realised that the pump is OK and started using it again.

What I'm saying is that the pump may be brought back to life with a good clean and oil change, and in any case as @Dannymoto mentioned it's £200 to replace if need be, though if you haven't bought it yet, the dealers should sort all of this out before you buy it.

I've not driven an A4 but I would say that an S car is going to be a lot more fun, I'm certainly loving mine!

 

[RichardT]

There are 2 cars that I am considering, the 2015 S3 Prestige I was referring to and 2017 A4 Premium with only 21500 miles on it with over 2 years of factory warranty left. Both cars are fine to me. I never had an Audi, so which one would you recommend for a piece of mind?

The two cars are not really comparable. If you like each one equally, then I would say that the A4 would be the one to go for as it’s newer.

 

[quattrorally]

Never had any problems with spinning wheels in a straight line, might be worth trying it in launch control. The haldex pumps are prone to failing due to the build up of gunk, if it has failed then if it’s under warranty then they will replace it as there is a TPI out for it. If not then you can buy a brand new from HaldexRepairs for £200.


Sent from my iPhone using Tapatalk

what's a TPI?

 

[Dannymoto]

what's a TPI?

Technical Product Information. They are documents relating known issues of the particular models of car.

You can often reference the TPI number when trying to get a known/common fixed at the dealers.

 

[ViperG]

Do they offer the service record on the cars? the S would have had two haldex fluid changes by now and a S-tronic fluid and filter change.
They would both need the same services. Launching and guessing I don't think you can tell much. Haldex is a kick in all wheel drive unlike the true AWD of a Torson Audi. Sounds like it is working though when it fails I typically hear that you get nothing from the rear wheels.
Fluid and filter change is pretty simple though. And a pump is cheap and easy two screws and a plug https://www.ecstuning.com/b-genuine-volkswagen-audi-parts/haldex-pump-repair-kit/0cq598549/

That's a link to my pump looks like the 2015 costs a little more but you get the idea.

 

[Slava]

Never had any problems with spinning wheels in a straight line, might be worth trying it in launch control. The haldex pumps are prone to failing due to the build up of gunk, if it has failed then if it’s under warranty then they will replace it as there is a TPI out for it. If not then you can buy a brand new from HaldexRepairs for £200.


Sent from my iPhone using Tapatalk

There is no warranty and if there is an issue, I may skip this car and purchase something else, unless dealer is willing to fix it first

 

[Slava]

The two cars are not really comparable. If you like each one equally, then I would say that the A4 would be the one to go for as it’s newer.

I agree, that S3 handles differently from A4 in corners. I did drive both of them and A4 feels like driving a luxury car which is worth money. S3 was pretty fast and agile, but that haldex issue and the fact that is has no warranty - holding me back from getting it.

 

[Slava]

Do they offer the service record on the cars? the S would have had two haldex fluid changes by now and a S-tronic fluid and filter change.
They would both need the same services. Launching and guessing I don't think you can tell much. Haldex is a kick in all wheel drive unlike the true AWD of a Torson Audi. Sounds like it is working though when it fails I typically hear that you get nothing from the rear wheels.
Fluid and filter change is pretty simple though. And a pump is cheap and easy two screws and a plug https://www.ecstuning.com/b-genuine-volkswagen-audi-parts/haldex-pump-repair-kit/0cq598549/

That's a link to my pump looks like the 2015 costs a little more but you get the idea.

I have seen the records of "carfax" by looking up the car's VIN #. So the S3 never showed any maintenance records 3 years, except when dealer got a trade in on the car recently and dealer also claim that maintenance was done, but I really think it was basically engine oil change. The A4 2017 does show 10000 mile service was done by Audi

 

[Slava]

My car (2014 with 44k miles) used to do this 'juddering' for a few seconds then launch and the computer did actually show a failed Haldex pump, and also when it was icy I got stuck on an uphill start and have to reverse down and get a rolling start to get over the hill which apparently shouldn't happen. However, I had the oil changed and filter cleaned and computer reset, since then I believe that the car is working fine. I've not had any wheel spin, so I can only conclude that the Haldex had issues (as the filter had never been cleaned up to 44k miles/3.5 years) and flagged the pump as faulty, however once the system was cleaned out, the car realised that the pump is OK and started using it again.

What I'm saying is that the pump may be brought back to life with a good clean and oil change, and in any case as @Dannymoto mentioned it's £200 to replace if need be, though if you haven't bought it yet, the dealers should sort all of this out before you buy it.

I've not driven an A4 but I would say that an S car is going to be a lot more fun, I'm certainly loving mine!

Since the car has almost 43000 miles on it, I assume haldex oil/filter change was never performed, but I want the dealer do this before I think about buying this car for $28700 which is a lot of money. A4 on the other hand is about $24000 with 21500 miles + under 2 years warranty still

 

[RichardT]

To me it looks like a no-brainer. Buy the A4.
I think you’ve answered you own question in the ladt couple of posts.

 

[Slava]

To me it looks like a no-brainer. Buy the A4.
I think you’ve answered you own question in the ladt couple of posts.

Here is the S3: https://www.autotrader.com/cars-for...e1=AUDS3&digitalRetail=true&clickType=listing

Here is A4: https://www.bellevuehonda.com/vehicle-details/used-2017-audi-a4-premium-WAUANAF42HN026990