Hi there,

 

In the past week or so I've noticed a funny noise as the fuel pump primes before starting the engine (it's an AXR code TDI PD 105 with 82,000 km on the clock). The pump seems to be priming normally, but there's what I can only describe as a cracking noise as it does so - almost like there's stones or ice in the fuel line and they're banging off the wall of the fuel line as they move along. I haven't been able to hear the sound with the engine started, there's no particular starting issues, and the engine seems to run completely normally, with no loss of power or smoothness. Is it any harm do you think, or is something on the way out?  

My vrs sounded similar to this, I don't know if yours uses the same pump mind you, but I think mine was down to a weak battery, as soon as I changed it the noise stopped and the pump generally got louder when priming.

Thanks for the reply That's an interesting one, when I changed the battery on my mk4 GTI a few years ago that didn't happen, but that was in the spring iirc. The Octavia's still on the original battery though, and with the cold weather at the minute battery symptoms would make sense. I've just been told by SWMBO that it's intermittent too - I only really drive it in the evenings when it'd be a bit colder still. Being a Diesel though, if it's the battery it won't be long letting us know