Aluminum readings from Ford 4.6 and 5.4 engines

[nickmckinney]

I don't post here much anymore, but I wanted to bring something up that I have learned well enough now. For those debating the aluminum readings in oil samples from Ford 4.6 and 5.4 engines, it has been 99.999% proved to me that it is not the crank bearings, it is the cam bores in the heads. I have pulled apart enough of these now to see the crank bearings are perfect in nearly every engine, and the cam bores show signs of scoring in nearly every engine.

So for those that see aluminum in your oil sample on one of these engines, don't worry IMHO. Its the nature of the beast, and the beast is in the cylinder head. It doesn't really hurt the engine from what I have seen here, they all ran just fine with the slight scoring they all seem to have. Now the valve guides and seals on the other hand.......

 

[Hirev]

Do you think its from mis alignment of the cam bores ? I used to see this situation in older motors a lot. But in those days the lead/babbit cam bearings sort of wore OK (no scoring) to help the situation out.

 

[nickmckinney]

No I think its just from a cheaper design. The cam bores are cut directly into the head, there are no seperate bearings. Heat treating or some other treatment at the cam bore might help, but from what I see the engines seem fine even with the scoring. I bought a ball hone to clean them up myself, and polish the cams to 600 grit. I don't worry about it to be honest anymore now that I have seen enough of the heads.

 

[punisher]

We saw that all the time. Neglected 4.6 comes in the shop and the cam bores are toasted. Most common problem was a semi-plugged pickup screen and wasted heads due to cam bore wear. Those old farts with Towncars in '91 learned you didn't treat oil change intervals the same way you did as with a 5.0. At least a 5.0 would twist the oil pump drive in half and turn on the oil pressure light nice and bright for the owner to see. The 4.6 would do irreperable damage before a customer noticed a problem.