The F355 is in for it’s annual service and this one will require an engine out and belt change amongst many other things. As you can see above, indeed the engine is now out.

Interestingly, there is some major corrosion present on the outside parts of the plugs as you can see above for cylinders 1 – 4

and cylinders 5 – 8, above. This is strange given that the corrosion is on the part of the plugs that is outside the cylinder! It is also interesting that two plugs on either side are largely unaffected while two others are quite corroded. The part that goes inside the cylinder is fine. This kind of suggests that somehow water has been trapped in and around the plugs for some reason.

Next was a leak down test on all the cylinders.

Most of cylinder are good, like above, except:

Cylinder 4 at 30% and

and Cylinder 3 also at 30%.

This is a loss of power in those cylinders and is typically caused by wear on the valve guides. Getting that fixed is a major job for the future but it good to have these readings as a benchmark.

No signs of issues with the evap system but got a replacement charcoal cannister just in case.

Still more work to be done but the corrosion on the spark plugs is a bit of a mystery and the valve guides will need replacing down the track as well.

Let’s wait and see what else is found.