[Palm]

As the title says I have a 2009 320i with around 77k miles. Every once in a while the car could take several seconds of turning over till it actually started. I didn't think anything of it as it was like once every few months. Now it will hesitate to start maybe 50% of the time. It can take 4+ seconds to fire and once started the idle is a bit rough. This mostly happens from cold. I checked for error codes and the only code was one relating to the thermostat which I have just replaced and that code is gone. So the car has no warning lights and no codes. Also once the car is running I have full power across the rev range and it's very smooth.

I have also recently replaced the stop start battery which had no effect. I have tried fuel system cleaner/treatment which had no effect. I also changed the oil and filter and the air filter.

There has been several tanks of fuel through it so if there was any bad fuel it's gone.

With no codes to look at I'm a bit lost. I have done some searches and it points to the high pressure fuel pump failing but that should throw some codes apparently.

Any ideas?

Thanks for looking.

Chris.

[Eddien123]

Mine would sometimes excessively crank and after I changed my spark plugs I noticed it was gone. If your plugs are on their way out they may struggle to make an efficient spark. Once the motor is on it cleans all the gunk out and that's why it smoothes out.

Just some advice. Either way plugs should get changed anyway so I just did it as maintence and it seemed to fix my problem.

[paulm3251]

Change the plugs if it still does it new starter.