Annoying problem

[A3some]

I'm hoping for some help to cure this annoying fault my A3 has got. When the car is warm, there can be a sudden 'flat' spot where there is no acceleration at all, the car just rolls. It can happen on the motorway for instance, just on the point of lane changing/overtaking, and I have to drift the car back in again to get out of the way of rapidly advancing cars.

It can happen when moving away from traffic lights or roundabouts, and no matter where my foot is on the accelerator pedal, there is nothing. This evening the 'flat' spot happened again, and lasted for four seconds at least, forcing a Nissan Micra to overtake me at its maximum speed (of about 28mph).

This problem coincides with a 'ticking' or clicking sound that comes from behind the dashboard??? As I lift or press the accelerator pedal this clicking can be heard off/on etc. , I'd never heard it before two weeks ago.

A VW specialist garage had the car for two days, and they replaced the thrust sensor, the 'repair' costing me nearly £190. This hasn't cured the fault.
I have contacted them to take another look but I'm not ready to take it in yet, I want to be able to tell them what to do.


Is that clicking sound anything relevant?? Because I'm convinced this is the cause of it, whatever it may be, a sensor or something maybe.

Has anyone else had this problem before?? :1zhelp:

[A3some]

Tough one for you, OK. I'll figure it out. Just need to figure out where the throttle control unit is.

[grayh]

When you took it in, i assume they plugged it into VAG com? Surely this would highlight any fault codes related to the problem? It sounds like it could be a power failure to fuel pump relay or something? Maybe ecu going into fault? Wahtever it is these intermittent faults are the most annoying. Does it coincide with heavy rain or anything like that?

[A3some]

When they first looked at it, on a Friday afternoon, I was told it was just a wiring fault and they'd sort it straight off. A 'mechanic' spent time looking under the dashboard. I waited 45 minutes and they couldn't fix it.

They then took the car from me for two whole days, and after their diagnosis (or the VAGCOM diagnosis!!) they replaced the thrust sensor.

When I got the car back I asked them if the VAGCOM showed clear/no faults & I was told it showed no faults.

They convinced me the car had been thoroughly tested. And they told me the fault was cured.

The fault occurs at any time rain or shine, any time of day.

Thanks for the reply.

[a8 tech]

fuel pump is very common and i suspect the fault code was a red herring as the engine cuts out causing crank sender to loose its signal and store a sporadic fault

[A3some]

The engine doesn't cut out though, just keeps running, but when I try and accelerate, the revs don't rise.

This lasts for a good four seconds at least, then it kicks back in again. Nightmare.

The reason why I think its something under the dashboard, as some tick-tick sound comes from there now if I lift and accelerate on the accelerator pedal.
Never happened before.

And I hear this same tick sound when the fault happens.

Is there a sensor located under the dashboard??

And thanks for replying, both of you.

[grayh]

The engine doesn't cut out though, just keeps running, but when I try and accelerate, the revs don't rise.

This lasts for a good four seconds at least, then it kicks back in again. Nightmare.

The reason why I think its something under the dashboard, as some tick-tick sound comes from there now if I lift and accelerate on the accelerator pedal.
Never happened before.

And I hear this same tick sound when the fault happens.

Is there a sensor located under the dashboard??

And thanks for replying, both of you.

Wow, i'm baffled, not heard anything like that before, it must be a dodgy connection to a relay or something or even a relay breaking down?

[pjbimmer]

I have an 06 A3 doing the same thing. I took it in and there was no fault code. They just told me that was the way DGS drives. Bull. It has stalled three times while in motion and from a dead stop. The gearshifts rough and jerks when I pull out of a stop or a rolling stop. I am taking it to a different dealer to see if they have a clue. I did find a service bullentin on it and told the service tech who was suprised that I had the information, but it did not help. Now the car is loud when idleing. may just sell the darn thing and I have only had it six months.

[A3some]

Mine isn't as bad as that I suppose. It'd be perfect if this problem can be solved, there are no other faults with it.

Perhaps the best thing I could do is run the car until the fault occurs, then just go direct to the garage to hook up the VAG-COM diagnostics, but without switching off the engine, because maybe the fault code is 'lost' for some reason.

[Andy500]

Did you ever get to the bottom of this? My 05 53 plate 2.0 fsi is doing the exact same thing and is accompanied by the same clicking sound!

[rydale13]

this fault sounds like a right pain!

i have an idea:

does the fault sound anything like this? If so I reckon it might be a faulty throttle body, sounds like the power to it is intermittent, causing the throttle to just dissapear...

on the 1st video, listen for the click right at the end. This is what a throttle body sounds like when it turns off and on.

http://thud.us/videos/car-av/TB-ign-on-divx.avi

On the 2nd video it clicks at the beginning and at the end. Ignore the high pitch whine on both the video,s its impossible to hear from inside the car, but the click may be audible.

http://thud.us/videos/car-av/TB-align-divx.avi

Luke

[A3some]

I still haven't had the fault fixed, although I have discovered that if I have at least 1/2 tank of fuel or more at all times it doesn't happen.

Well, until it happens that is.

The click always sounds like a weak tinny click, inside the dashboard. This might be a throttle control switch or something.

If I had the time to get it back to the garage, actually trust them to fix it this time, and not have the fault again I'd do that. 'Cos they owe me anyway because of the thrust sensor that cost me £180...but I haven't got the time atm.

So I'll keep plenty of petrol in it and hopefully the fault stays away.

BTW, the ticking sound is still there, so maybe this isn't a fault? I don't really know.

[A3some]

Since I've posted the previous post I've not had the fault occur, not once.

So I'm going to keep a good amount of petrol in the car to keep the fault away.

Just posting this to help anyone looking for answers for the same problem.

Unless as dumb drivers we actually have plenty of money to throw at garages to find obscure faults on our cars that is.

[Andy500]

Unfortunatly mine kept doing it regardless of the fuel level in it. I never got to the bottom of the problem as ive part exchanged it with Audi for a 3.2 V6 version, which incidently was back at the dealers 2 days later with a fault on the DSG!!! Wheres the often spoke about VAG relibility?

[A3some]

Reliability? Yes you are right, its more like liability. Still, when I look at my A3 and compare it to say, a focus or an astra I know which one I'd go for if given the choice, and it'd still be the A3.