Hard starting D12 2007

Had the truck for about just about a year now 633,000 miles on the truck, I would start the truck, Like I always do, put the key into the ignition and turn on position, let the truck do its system test after the third beep I turn the key to start the engines, she would turn over in about three seconds. Now it takes about 15 seconds or longer to get the engine to start in the morning. only thing that has happened since this time is the oil pressure sensor went out on it, The Volvo dearler put in new sensor, and it's been running fine for a week. my suspicion is that the sensor is bad, it does not detect crank case pressure!

After the truck start up, she start up as usual.

Dose any one have an idea, could it be the oil pressure sensor or something else.

 

How about the sensor on the flywheel since the oil pressure sensor blew three weeks ago, I imagine, that it has to be full of oil and grit. I think the sensor can't read when the engine is being turned over !

Does anybody else have any input on this, kind of trying to figure out where the sensor sits on the D12

 

No, hot or cold it takes 10 to 15 sce. To start the truck some times. Before it wood start in 3 sce. Like clock work! Only thing that as change was the the oil pressure sensor, it blu oil all over the bottom and the side of the engine.

 

It turned out to be a bad cam shaft sensor, you would think Volvo parts should be Perfect they are not, I replacing the cam sensor again, now the truck started up about two seconds hot or cold.