Scoring in cylinders. How did that happen?

[Nickolodeon]

Q7 3.0 tfsi 2015 4L.

Year and a half ago cylinders were fine.
Terrible oil consumption of 1 quart per 1000 miles quickly risen its appetites to 1qt per 500.

Several month ago started to smell gasoline in oil. Garage did this endoscope check saying they found corrosion and scoring. They are proposing ironcast sleeving. Compression in 5th cylinder is barely 8, the others 12.

For now they say fuel pump should be replaced which allegedly caused oil dilution.

Any thoughts?

P.S. Attached images links, but they don't show. Weird tooling.
https://ibb.co/rQvV2Yh

https://ibb.co/SQWjzrk

[Audibot]

Q7 3.0 tfsi 2015 4L.

Year and a half ago cylinders were fine.
Terrible oil consumption of 1 quart per 1000 miles quickly risen its appetites to 1qt per 500.

Several month ago started to smell gasoline in oil. Garage did this endoscope check saying they found corrosion and scoring. They are proposing ironcast sleeving. Compression in 5th cylinder is barely 8, the others 12.

For now they say fuel pump should be replaced which allegedly caused oil dilution.

Any thoughts?

P.S. Attached images links, but they don't show. Weird tooling.
https://ibb.co/rQvV2Yh

https://ibb.co/SQWjzrk

Consumption suggests piston rings. Scoring might have been a buildup of carbon stuck to the edge of the piston or chunked of the valves. I'm not sure how the fuel pump caused fuel dilution because it feeds the injectors unless it's way over pressure; injectors not working right sound more likely to me (like stuck open). If it ever had a lot of effort to start, could have washed the walls with fuel too.

On your images, you have to show the actual URL ending in .jpg (or similar).

[Zuzuwu]

We get a lot of q7s traded in at the dealer i work for and nearly every one of them has this issue. Carbon buildup in the rings causes poor lubrication and cylinder scoring.


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[namvar]

I had a 2013 with extended warranty. They finally replace the motor for me at 85K miles. Ran great until 210K miles but the oil consumptions was back to the pre-engine swap days. I had the engine carbon cleaned every 50K miles.

[AANgry90q]

High pressure fuel pumps can leak fuel into the crank case as they are driven off of the camshaft, diluting oil which can cause scoring/low compression. Carbon however is one of the biggest more likely killers as was said, (right up there with tunes) 10k plus oil change interval’s and poor quality fuels cause buildup so excessive clogs rings, can break valves, bend rods….that “corrosion” looks like the plating/coating on the cylinder walls delaminating….wear…


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