I was cleaning up the front cover that came off the blown engine from my base model, and noticed all these tiny cracks all over the inside. They don't appear to be very deep, but they can be felt. It's an S4 n/a, the engine was severely overheated, I suspect that has something to do with it.

Has anyone else seen this before? Any possible cause other than heat?

 

I'm pretty sure that's completely normal and ok, I'll get out my spare in a bit and check it out.

 

Casting marks. The cover is fine.

 

Looks normal to me, the front cover is one of the cheaper castings mazda ran. I have seen oil weep through those cracks very slowly, so I'll usually mediablast the fronty cover and then coat it with glyptal to prevent it.

 

i thought my oil filter pedestal was leaking, has very similar cracks all over but not deep. asked around and everybody said things like casting marks. now just got to figure out where the oil is actually coming from on that side of the engine...no work tomorrow,AMP energy drinks, coveralls.time for an all night'r lol