Car conking out and power reset

[clone_tk422]

Hi All

Got a 2007 Polo GTI and hoping someone can shed some light because the mechanic is scratching his head

The problem started where suddenly I would be driving along and power got reset as in the stereo reset itself and got a few warning lights but the car kept running.

Fast forward and suddenly once when I was turning into my driveway the car completely conked out

Took it to mechanic he ran the diagnostics and got back a code that the purge valve was faulty so he replaced it

This may not be linked to the issue but at the same time had the exhaust warning light on too so because of this got two new O2 sensors and that issue has gone away)

So after all this work done and driving along again the other day car conked out like 3 times in a couple of minutes! So the problem getting worse as last time it only did it once.

So take it back and he's scratching his head... he ran scans and only thing he got was low voltages.. he reckons at the time too the battery charge was low, and when testing it he got bad cells.. ok so eureka! Problem is bad battery or perhaps the terminals?

But now he has left the battery on to charge all night and its come back good no bad cells, and the car is starting every time He told me about he thinks the issue could be the Secondary Air Pump because I've got the issue when starting cold it makes a high pitched jet engine noise.. I don't believe this would be causing it to conk out this is my second Secondary air pump because the first one also got the high pitched noise (water in pump?) and now my second one has same issue and has had for a long time

Also I believe the pump is not needed as some have removed them and blanked them out and they are only needed for startup right? As Mechanic is saying could be injecting bad air into the car when its driving causing it to conk out?

At a loss now anyway and thinking if it was a bad battery before and its charged good now, go and drive it around again for a while and see if it does it again.. Battery was only a cheapie from Kmart but its less than 2 years old. Mechanic reckons cant be the alternator not charging the battery properly because that would trigger a light and a code?

Long post sorry but hope I can get this issue fixed.. only does less than 180K even though car is 14 years old Ta

[simon k]

The conking out sounds like the battery disconnecting itself, I'd check all the earths. It's not related to your SAI or O2 sensor and problem

And yep, removing the SAI pump is dead easy

[clone_tk422]

Thankyou so much yeah I thought battery issue. Terminals have all been checked and supposed to be fine.

Mechanic reckons if it was ECU it would throw a code as well

[Lucas_R]

Ignition switch? I had a somewhat similar issue in a Mk6 Golf GTI where the stereo would randomly turn itself off then on again (no issue with dash lights or the car stopping though) and I had to replace my ignition switch. Quite a common issue on the Mk6 GTI. An $80 part and 3 hours of my time and it was fixed (prick of a job to get the ignition switch out)

[h100vw]

I'd have a look at the strip fuses at the battery. Common for them to crack and become intermittent. Usual culprit is the Power steering, but it could affect any of the fuses.

[clone_tk422]

I'd have a look at the strip fuses at the battery. Common for them to crack and become intermittent. Usual culprit is the Power steering, but it could affect any of the fuses.

Thanks that's a good idea!