2006 6.0L Extended Cranking During Cold Soak

[mchan68]

I have one here that I've been unable to repair an issue with extended engine cranking thus far. The vehicle in question seems to have already had a Ford Quality Repaint engine replaced sometime in its history RETAIL (since it doesn't appear in OASIS). Originally, when it first appeared here, I replaced the oil filter with an OEM filter and cap during a service. I just replaced the engine oil pan (due to rust and and dents).

 

During cold soak, it takes forever (about 10 seconds of engine cranking) for ICP to build sufficient pressure to fire up. ICP sensor reading is not biased. I've already replaced an IPR (thinking about the numerous ones I've seen coming in on the hook with aftermarket oil filters that ended up taking them out). Once up to operating temperature, the engine fires up within the usual timeframe. I'm thinking if it were a high pressure oil system leak, wouldn't it be difficult or impossible to fire up once the engine is warm? For this reason, I am reluctant to do a high pressure oil system leak check. Any suggestions?

[Alex Bruene]

Port plugs will cause that.  As the engine soaks, the manifold drains completely, then it takes some cranking to fill the manifold back up.  Port plugs don't always cause a no-start hot scenario, but will eventually as the leak gets worse.

[Jeff Clyde]

Mike, I have also seen the small round headed plug in the oil rail leak; I believe it is about in the middle of the oil rail. It caused the same symptom, once started, it was fine.

[Matt Saunoras]

I keep 2 of those little round oil rail plugs on hand just incase.  I keep forgetting to take one out and check it so I know what to expect..  I've been lucky, never really had a starting concern that got the brain warmed up.