Gray oil

cee21 · Post by **cee21** » Tue Dec 30, 2008 7:39 am

My brother-in-law changed the oil in his 71 chevelle 454 the other day and the oil was gray. Not a little gray, or gray looking, but gray as a naval ship. He put aluminum heads on it and then put valvoline max life synthetic blend int it. This oil has only 800 miles on it and is 6 months old and he uses 110 octane (has to, it diesels with 93 al little). This is the first oil change with the new heads. What could have caused the oil to be gray?

Also, if he used full synthetic, could he have longer periods of no oil changes since it is not driven much? Say a year between oil changes?

prpleranger · Post by **prpleranger** » Tue Dec 30, 2008 7:51 am

is it aluminum gray or is there a water leak? water and oil mixed make nasty gray crap he could have a head gasket or intake gasket leaking water into the crankcase

cee21 · Post by **cee21** » Tue Dec 30, 2008 9:07 am

Dark gray. Not shiney, just a dull grey. He didn't notice any sort of water leak, or andy white smoke out the tail pipes.

MalcolmV8 · Post by **MalcolmV8** » Tue Dec 30, 2008 9:47 am

You can send a sample of the oil to http://www.blackstone-labs.com/ and they'll tell you more about your oil than you ever wanted to know.

cgrey8 · Post by **cgrey8** » Tue Dec 30, 2008 9:57 am

Ever since I started using synthetic oil, I go 10kmiles between oil changes. I was sold on synthetic back in the 90s when I read a study Mobil did with their Mobil1 oil where they tested for wear in an engine with oil changes every 3k, 6k, 12k, and 15k. The results of that experiment were that there was no discernible increase in wear between the engine that got its oil changed every 3k and the engine that got its oil changed every 15k. So just for simplicity, I change my oil every ~10kmiles. My original 2.9L V6 in my Ranger got pulled with 267kmiles on it and was still running the day I pulled the engine. The compression was a bit weak and it barely pulled itself up hills on the Interstate, but I would expect that from any small engine that went 250+kmiles. It may have been a V6, but it never was much for power even when it was new.

prpleranger · Post by **prpleranger** » Tue Dec 30, 2008 12:55 pm

not sure water in oil is a lighter gray almost white and he might not notice it in tailpipes if its going into crankcase, could possibly be main rod or cam bearings but i dont think that would turn all oil gray would just have alot of speckles it... it could be aluminum dust from the new heads if they werent cleaned after they were milled at the factory. could try changing oil and run it a bit but i would also recomend the oil sample route i work on over the road trucks and we sample everyone that comes in the door, thoes guys are good they will tell you everything thats in it.

as far as synthetic i was told by a rep from mobil that you just have to change the filter and add oil.... i think thats bs but who knows i dont think it will breakdown like conventional oil so a year may be possible