Audi A5 Intermittent Engine Start - Help!

[Matthew_s]

Hi everyone,

I'd be so grateful for your suggestions as to what could be wrong with my car.

I recently purchased a second hand Audi A5 S Line, 65 plate with 46k on the clock. 

On Monday driving back from work, I stalled the car and the engine wouldn't start up again for me. There was no crank at all in the engine. Managed to push the car to the side of the road, and tried the ignition a few more times and it started up again. Managed to drive it back home and switched the car off and back on again. This time it wouldn't start up at all. I left it a couple hours and it started up again normally.

There are no error codes on the dashboard, and all of the lights, radio etc seem to still work. 

I've taken it to a local garage who can't seem to figure out what the issue is. They've tested the battery, and alternator, all seem to be fine. They've also tested the clutch switch/sensor, as it's a manual drive, and they said that it's not that either. They did say that there a quite a few errors with low voltage coming up on their diagnostic tool. But I specifically asked about the battery and they said that it wasn't the cause.

This seems to only happen when the engine is warm. As it starts first time when cold. At the time of posting this the.garage said that it could be the "Key Reader" and/or electrical wiring. But that will be tomorrow's job. They also mentioned that they've tested the key, and there's no issues with that.

I'm absolutely gutted about this, and I would be very grateful for any help from anyone on this forum. I'm sure you frequently receive requests like this, but I will be respectful to the moderators and not "post and run".

Thank you

 

 

Edited November 27 by Matthew_s

[cliffcoggin]

If that was a recent purchase from a dealer take it back and get him to sort it out at no cost to you.

If that is not an option then the obvious problem is the battery, hence the low voltage warnings. If your garage test was done with a simple volt meter it will not have revealed internal battery faults. I suggest in that case you get the battery professionally tested elsewhere. That is not to say the battery is certainly the cause of the problem, but until you eliminate the battery as a cause it is pointless to look for other faults.

[Matthew_s]

46 minutes ago, cliffcoggin said:

If that was a recent purchase from a dealer take it back and get him to sort it out at no cost to you.

If that is not an option then the obvious problem is the battery, hence the low voltage warnings. If your garage test was done with a simple volt meter it will not have revealed internal battery faults. I suggest in that case you get the battery professionally tested elsewhere. That is not to say the battery is certainly the cause of the problem, but until you eliminate the battery as a cause it is pointless to look for other faults.

Thanks for your reply, Cliff. I will definitely consider this once I hear back from the garage tomorrow.

[cliffcoggin]

What news on this Gethin?

[Matthew_s]

Hi Cliff,

The car is still with the garage, they've unfortunately been unable to find the time to properly diagnose this issue for me. Which is becoming increasingly frustrating!

I'm keen for a local garage to sort this out and to claim back the costs from the warranty. 

The garage assured me that the battery was not the cause of these issues and were looking at the "Key Reader" and Immobilizer. But I'll be honest, this is all beyond my understanding of the inner workings of a car.

Praying that I'll hear back from them this week.

Thank you,

Edited December 2 by Matthew_s

[Matthew_s]

Just a quick update on this, and likely to be the last regarding this particular car.

I took the car to a Audi specialist for a second opinion who have confirmed there are two significant faults with the car. The first being the "gateway module", and will need a new part and subsequent coding. The second fault being excessive clutch wear which is causing overheating of the clutch plates and preventing start up when warm.

The car will be going back to the garage for a full refund. The used car market is an absolute minefield!

Thanks again for your replies.

[cliffcoggin]

25 minutes ago, Matthew_s said:

The used car market is an absolute minefield!

It always has been Gethin. There was a lot of truth in the TV series "Minder" four decades ago, and little has changed since those days.