Car takes 1-2 seconds longer to crank on a cold start? Any ideas?
 

The car runs great at all times, and starts fine when warmed up. But on a cold start the car takes 1-2 seconds longer to fire up. There are no service/check engine lights and I had the cars memory checked for stored faults and everything came up ok. I want to believe it is a crank sensor or cam position sensor, but I don't want to throw money at it if I am not sure exactly what is causing this. Glyn, any suggestions or anyone have any insight on any good troubleshooting? Thanks.

Update*

I removed all the connectors from the cam position sensors and cam shaft magnets to look for any corrosion in the pins and found no corrosion, but on bank 1 on the intake cam magnet sensor, I found a bit of oil pooled up inside around the pins, and bank 2 exhaust cam magnet, found a bit of oil pooled up in there as well. I sprayed them out with some cleaner as any kind of fluid in contact with any part of an electrical system can cause a short. I will post an update once I can perform another cold start. In the meantime, anyone who has experienced this or has any ideas please let me know!

in my case, I found that if I turn the key gently and slowly to the position that just connect the starter to crank, it startup perfectly fine. But if i just turn the key all the way down, there will be at least 6-7 crank before the engine fires up.

So weird. :crazy:

I believe there is a recall on the cam solenoids or cam magnets.

B21: MERCEDES DRIVEABILITY 2012070002 cam solenoid

Will they replace the cam solenoids or just replace the harness?

*Update #2

Went out to perform a cold start on the engine and it started up great for the first time in a month! I believe I have solved the issue with the hard cold start by cleaning out the bit of oil that was found sitting inside a couple of the cam position sensor electrical connectors.