While doing my 5000 mile service recently I came across this. Not sure if this a problem or "normal". The ridges feel raised which makes me think it had to do with casting. It just seems to me to be an awful lot of casting marks. Opinions?
Oil pan cracks or casting?
-
It's completely normal. It has them all over the place. What freaks me out is the Styrofoam designs all over the block. The liquid aluminum was poured into a Styrofoam mold and it leaves the surface that looks like a cooler.
-
The tooling for alum diecast is heat treated, and as the tooling is used in the casting machine the surface gets stress cracks. These small hairline cracks transfer into the surface of the casting. They are harmless as they are just a reflection of what the moulding surface looks like.
-
It's completely normal. It has them all over the place. What freaks me out is the Styrofoam designs all over the block. The liquid aluminum was poured into a Styrofoam mold and it leaves the surface that looks like a cooler.
Normal or not, it disturbs me when my engine block looks like a poorly-made Styrofoam cooler!
-
Normal or not, it disturbs me when my engine block looks like a poorly-made Styrofoam cooler!
.
It sorta started out as one .........
........
.
-
From the video it looks like a great method for making detailed castings, but the end product can still look like crap when it looks like Styrofoam!
-
A little more info that I learned ..... When poured this way the engine blocks have passages that sometimes develop cracks. Water and oil passages kinda mix together when this happens. It is actually a known problem for these engines to develop this issue when they are machined and cleaned up when building them with forged goodies. The vibrations during these processes can cause the porous castings to vibrate and give way. You need to pressure test the block after its machined to make sure a water passage way didnt vibrate and crack through to another area that shouldn't have water.
General Motors has known about the issue and changed from a pouring method to a pumping method so that bubbles and imperfections are minimized.
