Doesnt start once hot

[jazz5000]

Hi
Have a 1.4.

Car starts fine first time its started for the day, Then when driven and parked up it will fail to start.
When i put the key to the start position there is no cranking. Only way is to bump start the car or let it cool down for around 20 minutes.

Not sure if its a starter problem or a sensor. Any help here guys.

[rio_gti]

crank sensor?

[jazz5000]

Just scanned it with vagcom:

2 Faults Found:
16804 - Catalyst System; Bank 1: Efficiency Below Threshold
            P0420 - 35-00 -  -
16712 - Knock Sensor 1 (G61): Signal too High
            P0328 - 35-10 -  -  - Intermittent
Readiness: 0000 0000


Would this mean the crank sensor?

[jamie16v]

Just scanned it with vagcom:

2 Faults Found:
16804 - Catalyst System; Bank 1: Efficiency Below Threshold
            P0420 - 35-00 -  -
16712 - Knock Sensor 1 (G61): Signal too High
            P0328 - 35-10 -  -  - Intermittent
Readiness: 0000 0000

it`s KNOCK sensor, not a good thing really, are you mapped? what fuel are you running?..
the non starting issue could be due to a sticky starter motor solenoid.. you need a new starter by the sounds of it.

Would this mean the crank sensor?

[jazz5000]

No not mapped as its a 1.4

Just running regular supermarket fuel

[jamie16v]

not starting once warm sounds like a coolant temp sensor tbh..
also supermarket fuel isnt the best for knock control.
delete the codes, and see what comes back!

[SI74]

I would go with along the lines of coolant temp sensor of the fuel one.

[xxChrisxx]

Not cranking? Starter.
The fact that it bumps means the fuel and spark is ok. Try belting the solenoid with a mallet.

Also the knock is not the fuel you are using. The 1.4 is pretty agricultural as far as engines go and 95RON is 95RON is 95RON. So buying Shell fuel save, or Tescojuice, it'll have basically the same knock characteristics. As it all has to meet standards, or it can't be sold, in many cases it'll be the same fuel stock. The difference is lubrication and other assorted additives.

With a signal too high code, it's more likely that you've got a broken knock sensor/wire.

[jamie16v]

i stand corrected, didnt read the bit where he said it`ll bump start..  sticky solenoid, and i also agree with the knock sensor wire.

[jazz5000]

Thanks for replies,

I have changed the coolant temperature sensor last month as i used to never get a reading on the clocks before.

When i try to start once its warm it does slightly crank very slowly and after around 3-4 tries it stops cranking.



Also where is the knock sensor located so i can investigate

Thanks