Morning guys, 

I’ve got a 2008 Octavia Scout 2.0l diesel and had a hot starting problem for a while now when car is cold no difficulty in starting. When the engine is at running temp and I stop to get petrol or park or Stall the engine. The engine will crank over really slowly as if the battery has low voltage, and struggle to start and sometimes doesn’t. Charging circuit is charging at over 14 volts  and battery puts out 12.8 volts.

The obvious thing to me would be a problematic starter solenoid or a loose connection to it. However I wondered if there are other common faults which would cause this to happen?

 

Peter

Edited 11 February, 20233 yr by Knodty

I think you're on the right lines.  I'd be checking earthing points and straps if it were me - poor earthing preventing the amps getting through, although that it only happens when hot kinda contradicts this.

 

I was trying to find a poor starting problem on a mate's FIAT a few years back.  Turned out to be the main earth strap corroded inside its plastic sleeve and not visible.  Found after some head scratching by by-passing the strap temporarily with a jump lead.

 

Have it scanned for fault codes?

 

Gaz

Haven’t scanned for codes lately as it never showed up before when I had the fault. 

It's a common fault and detailed to death on this forum.

 

Of course putting petrol in a diesel won't help ( ͡~ ͜ʖ ͡°)

 

Check the battery connections and if possible try a jump start when it's hot, if it cranks in a lively fashion and starts without issue the battery is dickered.

This was a problem on the Mk1 Octavia and the Mk 2 problem is probably of the same cause.

The Mk1 was allowed to start at low cranking revs when cold but when hot, starting was inhibited until a higher cranking speed was achieved.

So the question is why is the cranking speed too low?

As said by others, the two major problems are a battery that no longer produces a high enough current, and poor connections introducing resistance into the circuit between battery and starter motor.

As said by MicMac, try a second battery for a jump start.

If it works then try a newer battery in the car. Also check for corrosion at all connections, especially at the earth strap on the engine.

 

I see your point,  however surely if the battery was on its way out it wouldn’t produce 12.8 volts?

Just been too busy to look into it tbh. 
Thanks for your help Guys I’ll let you know how i get on. 
👍🏻

A battery can show good voltage yet not produce enough current to light a 55W halogen bulb.

 

A garage can perform a battery capacity test in seconds.

My 2.0 BKD TDi has done this since forever. Had various new batteries over its life. Cleaned all the earthing points with emery paper etc etc etc. No fault codes.  Starts on the button when cold  (had a slight issue last year when it wasn't driven much). But when hot it takes a few cranks for it to fire.  I just take it as a characteristic of the engine now.

The part that causes the problem is the starter turning too slow. This happens when it is only a little worn. I went round in circles with this with earthing points, new batteries, a new starter. The only thing that fixed it in the end was a remap. I was living with the issue happily and then realised the map fixed it.

 

The way I lived with it was to turn the car over, back off, then start properly. It always started this time rather than chugging and labouring the start.

@MicMacwhy the groan?

@MarkyG82

Why stop there, when the fuel tank runs dry just buy another car!

I don't understand sorry. Was just sharing my experience of what I changed to solve the problem. A map was the only thing that finally solved it for me.

@MarkyG82

Relax, it's all good.