Hello all,

This is my first post here, and I'm working on my first ever rebuild. I'm looking for some advice on my scored camshaft bearings on my 4.0 SOHC.


On a particularly cold winter morning in Wisconsin, I cold started my oil burning (150k miles) 2010 Ford Ranger 4x4 and the timing chain guides decided to delete themselves from existence and let the chains make a TRTRTRTRTRTRTRTR sound as they slapped around in the heads, so I decided to immediately stop driving that vehicle to prevent further damage.

I heard the noise coming from around the passenger side head, and after reading into it and finding out the motor had to be pulled to do the guides and chains, and pissed off that my motor was burning oil, I knew what wanted to do. It's rebuild time.

I took the motor out, started stripping it apart piece my piece, bag and tag, blah blah --->

The cam bearing towers closest to the timing chain sprockets on both the heads are scored up (image attached). My scratchy machinist finger tells me were dealing with something MAYBE .002-.003" deep on the scratch over the oil galley hole thingomobob. The rest of the bearing surfaces look great, it's just the two.

The tolerances and clearances for the cam and the bearings are still in Ford's specifications, so the question is, will this amount of scoring (in the image) be an issue for reliability, oil pressure, or performance? The scratching on the cam cap matches and is no better or worse.