sam i am

Hello all,

My complaint is that the S has a catastrophic misfire when the engine is cold and thins out as the engine warms up. MIL flashing. I am worried about the CAT. I would love to look at some engine PIDs, but I do not have access to a scan tool. I did a few basic test.

First, I hooked up a vacuum gauge. The needle was around 19" Hg and had a steady regular drop, but caught itself back quickly. If I could go back now (too late), I would raise the RPMs because I suspect I may have leaking valve guides (you will see below)

During the cylinder drop test, I found that all cylinders were contributing.
After, I inspected the spark plugs and piston heads and found some good info. Test results follow:

Cy#4) dry with black spots on piston (gap .042")
Cy#3) dry with black spots on piston (gap .0425")
Cy#2) wet, sooty, oily piston (gap .042")
Cy#1) wet, sooty, oily piston (.0375"! <---suspect overheating?)

All plugs looked the same. I will upload a pic tonight.

Cylinder 1 and 2 seem to be where the issue may be. The oil on the piston leads me to believe that the valve guides may be worn. I do run the engine hard, but not every day. Recently started using Amsoil and preformed an injector cleaning service. No other repairs have been preformed lately.

If anyone has any direction, help is welcome. May upload pic of spark plug tonight. Ty!