Got about 1300 miles on my newly built motor, and I still get this grey stuff on the dipstick. Assembly lube still coming out? Compression tests good: 1-190, 3-200, 5-214, 2-190, 4-190, 6-190. I just want to know if it's normal for this grey stuff to be on the dip stick? Sometimes there's more grey than other times. Oil looks like a healthy brown color under the light on the dipstick though. I've never actually had a brand new engine lol...

Car pulls strong, and runs fine, just stalling occasionally through idle while in neutral or clutch in. Idle is set to 1000rpm. I have C8 cams though, maybe they are just causing this. Doesn't happen often at all.





Also, at WOT/high RPM, I am noticing black smoke. I think I'm just running rich perhaps. Injectors are at 94% duty cycle, and are the OEM original injectors with 117k miles on them. Throttle body, ignition coils, and MAF sensor is the same. Everything else has been replaced.

 

How about doing a UOA to get a fuller picture of what's going on?

 

Ya, going to do an oil analysis. Just wanted to know if anyone with a built motor would chime in.

 

The gray, is it sort of like bird poop ?

 

No, it's sort of like barely anything there. Not enough to be feelable. I am wondering if it's piston rings still wearing in, or cross-hatching from the hone? Magnet doesn't pick it up.

I know the bird poop like feeling you're talking about. My last engine had failed piston rings, and who knows what else - the oil pan I had to clean up all sorts of grey "bird poop."

 

Lack of bird poop rules out water and oil mixing so you can breathe easy on that front.

What you have is lube from the engine build. It will be gone shortly.