Right I have been waiting in the wings and have now read all the posts.
So I have had this issue for months and have covered 20'000 miles without the fuse in. Note it is not fun when the car loses grip, so drive safe. itâs like a 200BHP 1980 front wheel drive hot hatch with no tranction control, if youâre old enough to have owned one of them.
My issue started after I had new tyres put on the front (Audi A3 2.0T Quattro 2006). I then did a 100 mile journey and noticed my ESP light flickering when pulling out of a lay-by. Thought nothing of it. After returning home, I then did another 100 mile trip no problems. parked my car and went to the office. Came out 8 hrs later turned the car on (no error lights) and drove away. Straight away I had clonking noise from the real wheels. Like Haldex was engaging them at the wrong time. The noise is there when driving in a straight line, turning, just moving it happens.
I changed the Haldex controller, this did not fix the issue. so removed the fuse, and itâs been like it since. Very annoying!!!!
After reviewing the Audi manual (get it from ebay for about 7quid) there are a number of tests all with fuse in:
1. Handbrake lift it up one notch - Yes this stops the noise
2. Pull away in second gear - Yes but as soon as I turn a corner or the front wheels slip noise comes back
3. Drive along and press the brake at the same time - I will be doing this, this weekend.
I had an ex Audi guy check the car over, he noticed the Haldex oil had grey tints in it, and stated the Haldex inside was chewed up. After much searching I found my car had the Haldex oil (this was by tracing the history back to the original owner) changed at 20'000 miles. This issue happened at 60'000 miles.(note Haldex is meant to be change every 40â000, so this fits in line with not changing it) But the service book never stated any of this, so much for full-service history. I have sent email to Audi UK stating I'm not happy, but as its a second-hand car not a leg to stand on, but it made me feel better.
so what's next
1. Left foot braking
2. Handbrake 1 click - Could be ABS unit if this does not work - test again to be sure
3. Check earth strap - Never knew about this until reading all the above fingers crossed
4. Does ABS work with Fuse out â Yes ,loads of wet leaves about this time of year.
Could be
Corroded ABS wiring
Earth Strap â this interests me the most and I really hope itâs this.
Haldex Unit
PRE Charge pump
Speed Sensors
It does not sound like Rear Diff â Do you agree?
I will know more at the weekend. But what I find interesting and what is new to me is the speed sensors, as after the tyres where changed the car never felt right, it went back and they stated a weight had come off. But the steering wheel was sitting off centre, they stated itâs because my aftermarket wheels were not Audi. I now think they may have damaged the speed sensors when changing the tyres, if I can prove this even though itâs been months since they were changed I will be looking for compensation.