dirty rusty cylinder from e85?

[Shredd]

I recently changed spark plugs and decided to check with a flashlight down in the hole and the piston looked all dirty brownish orange in color. I have been using e85 for past year and was wondering if that could actually be rust or is that normal for 60k mile car. Not sure If you can tell from pictures. Should I be using any kind of additive?

 

[black92]

Pistons should not rust, at all. My first thought is just a browning on the piston from combustion, but I'd imagine E85 would leave it pretty clean. Are you running an oil separator? I'm wondering if maybe that's a light coating of oil?

 

[Shredd]

I bought it with 50k miles and it didnt previously have oil seperator until I bought it and put 10k miles on it, I put about 3k miles with e85 so far. Is there anyway of cleaning that thru additives or should I just leave it alone?

 

[gimmie11s]

Pistons should not rust, at all. My first thought is just a browning on the piston from combustion, but I'd imagine E85 would leave it pretty clean. Are you running an oil separator? I'm wondering if maybe that's a light coating of oil?

exactly. Its not rust on an aluminum piston.

The crown of the piston will have a browish color due to how clean the e85 burns vs. the black crown of a carbon crusted piston run on gasoline.

 

[SID297]

Agree with above. From what little you can see I would say it looks pretty good.


Sent from my iPhone using the svtperformance.com mobile app

 

[CobraBob]

Note the color differences pointed out by others above. These are actual photos of pistons from the same engine. It had been on 93 octane fuel and then the owner switched to E-85 and drove the car 3,000 miles.

Piston after 3,000 miles using E-85.

.

And here's an adjoining piston 3,000 miles earlier on unleaded 93 octane fuel.

 

[Shredd]

Good to know thanks for the info. Ill keep using e85