Normal piston deposits?

[chris719]

Scoped the bores on my 94k mile car with unknown history. A lot of white deposits around the edge of the piston crown. Any reason to be concerned?

Thanks!

[maupineda]

White deposits may indicate lean conditions. I have not checked mine to compare, but others that have taken the head off may have more data points. Overall your pistons look clean, I would of expect more carbon build up.

[cobra]

I have seen this before on exhaust valves, but not pistons. If it's running fine I wouldn't worry about it - it could be indicative of oil burning, running lean, lack of fuel additives, etc.

[fattycharged]

which cylinder? That looks to me like mineral deposit from water...er coolant

[Cubieman]

which cylinder? That looks to me like mineral deposit from water...er coolant

That was my initial impression as well.

[Slideways]

Normal, in fact, the top of the piston is so clean that you can still see the circular pattern on the piston from when it was new. This is what you expect to see when an owner only uses premium fuel and exercises the engine when it is up to temp. Also, like most well-maintained S54s, it is not burning oil.

[fattycharged]

Normal, in fact, the top of the piston is so clean that you can still see the circular pattern on the piston from when it was new. This is what you expect to see when an owner only uses premium fuel and exercises the engine when it is up to temp. Also, like most well-maintained S54s, it is not burning oil.

I haven't seen any without, is that common to see them worn off?

[Slideways]

I haven't seen any without, is that common to see them worn off?

They won't wear off unless the piston has a hole in it . Said that because the alternative to a clean piston, like OPs, is one that is completely covered in carbon from the engine running rich or consuming oil.

[fattycharged]

They won't wear off unless the piston has a hole in it . Said that because the alternative to a clean piston, like OPs, is one that is completely covered in carbon from the engine running rich or consuming oil.

gotcha mine have 100k and you can tell how long it's been sitting and how many times I've started it up to just move it and not gotten up to operating temp

[chris719]

which cylinder? That looks to me like mineral deposit from water...er coolant

All 6 look like this to varying degrees. Not losing any coolant that I can see either.