03 SD 6.0L. hard to crank sometime, like last night

[mardad]

Third time it's happened. Runs great then won't crank. Last night my wife pulled us and it cranked. Water in fuel light not on. Runs like a scalded ape when it's running.

 

[DaveBen]

Welcome to SDD mardad. How old are your batteries??? They will give you a very unreliable cranking of they are too old.

Dave

 

[patrickc]

Sounds like batteries or starter motor drawing. I would have the batteries load tested.

 

[dzl_x_4x4]

I just had my 2 batt's and altenator change Wednesday. When you say it won't crank do you mean it turns over but does not start? When it is turning over is it turning over good (like normal). If it turns over good (i forget what RPM's) that should fire the injectors and it should start. If it doesn't turn the motor quick enough I would suspect the CPS, on some years it would go out in a heartbeat (like a chebby). When my CPS went out, it would start when the motor was cold, but not start when the motor was hot, consistently. A trick on my 2000 is to watch the tach when starting it and see if it reading RPM's while trying to start it. Let us know what it was!