Here we have a 2012 Ford E-350 Super Duty with a 6.8L V10 that was having multiple cylinders misfiring. After checking for the basics, air fuel and spark all were working as they should. Checking compression showed the engine was having issues in the cylinder sealing d.epartment. Our technician Pete then performed a cylinder leak down test compressing the cylinder with air while the valves are closed. In doing this he was able to determine the cylinder was leaking past the intake and exhaust valves. This is from “burnt valves”, a condition that causes pitting at the valve “seat” where the valve seals the cylinder. Burnt valves happen for many reasons but no matter the reason, the cylinder heads needed to come off and they received a full rebuild from our favorite machine shop.
Before getting the heads back we also decarbonized the pistons and rings to make the bottom end fresh and sealed. The customer took our advice while we were there doing the timing chain and guides along with the tensioner, water pump, and spark plugs and a full engine reseal was only fitting due to the advantage of having the engine out saving him a lot of time, money and aggravation later. We were able to resurrect this V10 quickly and she's running as good as new with many many more miles ahead of her.
(As you can see, we're all willing to dig in and get our hands dirty, even Jodi is a willing participant)