[sbaptistes]

Hi

will i was replacing my spark plug on my 2015 5.7, i take picture of my pistons using an endoscope camera, and I wanted your feedabck about their conditions (regarding the color...)

What do you guys think ? Is it rust ? Normal ?

Engine tu peux very well

 

[Nuke]

I see nothing alarming. They are relatively clean and carbon-free. Combustion appears to be occurring as expected - completely and efficiently.

How many kilometers (or miles) on the engine?

Original spark plugs still in use?

 

[sbaptistes]

Thank you

55k miles, i replaced with iridium spark plug (ngk 4469)

 

[Stay Thirsty My Friends]

How many miles? (Replied at 55k)

You have done a good thing here. More people should invest/borrow tool to take these pictures. The only problem is there is generally no reason to pull a plug and risk damaging electronics just to take a picture of your cylinders/pistons on a good working engine. So that means the first picture might not be taken until 60k+ miles if one decides to change plugs.

I have taken apart 3 engines with a variety of engine miles on them. My expert engine builder was never worried about the piston tops as much as he was worried about the condition of the cylinder walls and rings...with one caveat: You would hope the pistons pretty much all look the same...and in your case they do. The pistons tops are not lubricated like the walls and take most of the heat, and also need to be light to reduce stress on the engine. As a result, pistons are typically aluminum alloy, so that is not rust you are seeing, just the result of exploding fuel on the surface.

I did a search for used 5.7 pistons. They pretty much look like yours. So, you are probably in good shape. The bottom line, would I take that engine apart to replace the pistons based on your pictures? Nope. Hope you get another 150k out of them.

 

[Nuke]

Thank you

55k miles, i replaced with iridium spark plug (ngk 4469)

The original plugs should have already been iridium, but either way, those are doing you well, and they should last 100K miles before needing to be replaced.

👍

 

[sbaptistes]

Thank you all for your answer, i feel better now

 

[Stay Thirsty My Friends]

Also...might be too late and not possible with your tool....if you could take a picture looking up at the valves.

One valve will look like your pistons, black and charred...this is the exhaust valve. The other valve might look different as it is your COOL AIR INTAKE VALVE.

Before fuel injection, the intake valve was not only cooled by incoming air but by evaporating fuel. So, it would look much less burnt/charred than the exhaust valve which is probably one of the hottest components in the engine.

Not sure what an intake valve will look like on a fuel/port injected engine...but again as long as they all look similar you are probably in good shape. I believe our 392's are PORT INJECTION so I would expect the intake valve to be cooler. I did a quick search for valves and did not see any images I could trust.

 

[Middleagecrisis]

As mentioned above, very little carbon build-up, which is a good thing. The reddish discoloration could be a byproduct of an additive in the fuel your using, or a fuel additive you may have added recently in the past.