The 5.0 GDI and the 3.0 GDI motors have been having issues with carbon deposits on the valves.

This is an inherent design flaw in the GDI motors. Since the fuel injectors are directly positioned in the combustion chamber, fuel never passes the valves, thus never cleaning them. With engineers working to increase motor efficiency, they have reduced the piston ring tension rates. deposits form on the rings leaving gaps in the ring seal allowing fuel and air to get in the oil and for oil to get into the combustion chamber. Once oil gets into the combustion chamber it looks for the coolest place to rest, back of the valves.

These motors have been dropping valve seats and causing owners to have to replace or machine heads, not cheap.

We have been doing the BG petrospecs EPR engine service at our shop. While this will not remove the carbon on your valves, it will emulsify the carbon deposits on your rings creating a uniform seal on the cylinder walls, restoring compression.

Here is a link to the BG explanation:

https://www.bgprod.com/blog/under-pr...-piston-rings/