Wondered if anyone could help. I'm having an issue where if I drive a short trip, my car then won't start. It tries to turn over, but then just clicks. Checked the voltage before and after start, and it seems to line up with what the Internet suggests as acceptable levels, so doesn't seem like it's an alternator issue. Bad battery perhaps? It's only a year old and showing green on the indicator.

Thanks in advance!

2012 Octavia 1Z estate 2.0 tdi

Edited 11 October, 202511 Oct by vanillapodfan
Missing info

If it clicks from alternator it may be a poor connection at alternator or bad chassis earth or coroded/dirty battery terminals. Sometimes a connection will fail when it starts to warm up. It may also be a low/failing battery. It just takes one cell to be poor and the battery wont hold a proper charge. enough to start but not being charged enough to restart after a short journey. Check as well that the battery light illuminates at pre ignition and goes off when car is running.

Alasdair

The "click" is the solenoid on the starter motor activating but not sending the power through to the starter motor.

Bad earth

Poor connections

Failing solenoid

Failing starter motor

It shouldn't be a 12 month old battery if it's the right one.

If you have a battery charger put it on battery overnight and check voltage across battery in morning and see if it makes a difference. As previously said a year old battery as long as its the correct one shouldnt be the problem but its not unknown to get a battery that fails prematurely.

Battery should read voltage aprox as follows

1. Engine running:

   13.8−14.5 volts

2. Engine at rest (fully charged):

   12.6 -12.8 volts

Thanks all for your suggestions. Replaced the battery and that seems to have solved that issue, however now we have a new issue 👌 love cars so much 😂

1 minute ago, vanillapodfan said:

Thanks all for your suggestions. Replaced the battery and that seems to have solved that issue, however now we have a new issue 👌 love cars so much 😂

If you only bought the battery 12 months ago it should still be in warranty

Might be worth checking voltage at rest and voltage when car running anyway just to check the alternator is charging battery properly. Whats your new problem?

Alasdair

53 minutes ago, Alasdair1 said:

Might be worth checking voltage at rest and voltage when car running anyway just to check the alternator is charging battery properly. Whats your new problem?

Alasdair

Thanks Alisdair. Checked them and they fell well within the expected range.

The mew issue is the car is turning over, but won't start, and it throwing up a P0091 error code.

2 hours ago, vanillapodfan said:

The new issue is the car is turning over, but won't start, and it throwing up a P0091 error code.

This code suggests a fuel pump or relay problem.

https://www.ross-tech.com/Search-Results.php?q=P0091

I agree with above. Sounds like a fuel/relay/wiring problem. Pulled this from rostech

P0091/000145 - Valve for Fuel Metering (N290): Short to Ground

Possible Symptoms

• Malfunction Indicator Light (MIL) ON

• No start or performance problem(s)

Possible Causes

• Wiring and/or Connector(s) from/to Transfer Fuel Pump (G6) -or- Fuel Pump (FP) Control Module (J538) faulty.

• Transfer Fuel Pump (G6) faulty. See Special Notes

• Fuel Pump (FP) Control Module (J538) faulty.

Possible Solutions

• Check Fuse(s), Wiring and/or Connector(s).

• Check/Replace Transfer Fuel Pump (G6). See Special Notes

• Check/Replace Fuel Pump (FP) Control Module (J538).

Electrical gremlins can be traced to earthing problems.

In a 13 year old car check the negative to body connections and clean them up.

3 hours ago, Stonekeeper said:

Electrical gremlins can be traced to earthing problems.

In a 13 year old car check the negative to body connections and clean them up.

Please forgive my ignorance, but where will I find negative to body connections?

1 hour ago, vanillapodfan said:

Please forgive my ignorance, but where will I find negative to body connections?

Not got access to an Octavia but The main one will be the negative lead of the battery to the body. others you need to find by looking for wires that are bolted to the body elsewhere. Usually a strap from the body to gearbox/engine, wires near lighting that terminate at the body. Near the fusebox. Also components that are bolted to the body could be loose if the body is rusty and they may rely on that connection for earth.

Found this on here. It may be of some help . The most common ones are in the engine compartment. Check that the fuel pump in tank is actually running as well. Think its accesible under rear seats. Check the wirin and connector there to as my sons fabia had worn through.

Alasdair

6 minutes ago, Alasdair1 said:

Found this on here. It may be of some help . The most common ones are in the engine compartment. Check that the fuel pump in tank is actually running as well. Think its accesible under rear seats. Check the wirin and connector there to as my sons fabia had worn through.

Alasdair

Thanks so much Alisdair, I'll see what I can do!

Just in case anyone was interested, I ended up calling the AA out, was told it was 100% a fuel pump issue, replaced the fuel pump, and the issue wasn't solved (£100 down the toilet). Had a couple of mates come over, checked the fuel filter (all clear), checked the air filter (just in case), and when one of my mates rang one of their mates we were pointed at the secondary fuel pump (I think that's what it's called, the one next to the fuel filter). I unplugged the fuel pressure valve (I'd been looking at the one on the fuel rail), the dash light vanished, and it started immediately. Praise be.