Replace or Reuse?

[trydrew]

Tonight I decided to clean off some of my engine parts, while everything is waiting to go back together. I came to the rear timing plate/engine front cover. As I removed the grime, I started noticing a pattern of cracks and stresses in the metal surface. Im pretty sure this isn't normal and I am planning on replacing the part, considering its position on the engine.

I guess what i'm asking though is why would the aluminum get like this?

 

[jdub]

Are those just surface cracks or do they travel down into the metal?

I've coated a bunch of these...that's the worst I've seen. Most are small fractures in the casting and will cause no harm.

 

[trydrew]

Are those just surface cracks or do they travel down into the metal?

I've coated a bunch of these...that's the worst I've seen. Most are small fractures in the casting and will cause no harm.

There are fractures on both sides, but the lines do not run consistant. In other words, there are cracks on one side with little or none on the opposing side (same spot). It still worries me though, because in some places it seems to break casting and stress out. Let me go look again...

 

[trydrew]

It's odd. Ive taken a closer look with a magnifying lens and all the marks protrude off the cover. Combined with a little grime, they appear to be cracks with shadows. That threw me off. I took a look also at the top edge where the markings would continue off the part, but there is no visable sign of internal stress; Only slight thickness variations where the markings ran to the edge. Ill take another look at it when im not so tired, but I guess i'll reuse it.

 

[jdub]

I've seen those marks...if they are like you describe, they are from the casting process. Do this...take a wire cap brush on a grinder or drill and hit the marks. If they smooth down with no crack, you have no problem

 

[spoolme]

sand em down and see.

 

[trydrew]

sand em down and see.

I was planning on doing this... I like smooth aluminum lol.

Ill let you know how it turns out.

 

[spoolme]

heres what i did with mine.

 

[pb92supraturbo]

Looks like normal casting ridges to me. Mine look similar when I replaced my timing belt and I've had no problems. I cleaned the cover really well and inspected it thoroughly before reassembly. I'd reuse it . . .