Originally Posted by 02slammedranger
Well now im going to have to check the tsbs and ssms today at work
In case you have trouble locating it, here it is.
MIL ON WITH VARIOUS MISFIRE RELATED DTC'S P0300-P0306 AND P0316 - 3.0L-2V VULCAN ENGINE
Publication Date: December 15, 2005
Some 2004-2006 Rangers 3.0L-2V "Vulcan" vehicles may exhibit:
Malfunction indicator lamp (MIL) on with diagnostic trouble codes (DTCs) P0300-P0306 and P0316
Rough running at various RPM
This may be due to an engine exhaust valve seat recession causing a loss of compression. Refer to the following Service Procedure to diagnose exhaust valve seat recession.
Perform a power balance test to clarify if a cylinder is misfiring. Identify and keep record of any cylinder that has a concern.
Perform a manual compression test with the spark plugs removed to locate any cylinder that may have low compression. Refer to the appropriate Workshop Manual, Engine System, General Information, 303-00.
If no low compression is found per shop manual instructions, proceed with normal misfire diagnostics per the Powertrain Controls/Emissions Diagnosis (PC/ED) manual for the appropriate model year.
If low compression is found and it is a cylinder that had a misfire on power balance, perform a leakdown test to determine the source of leakage that may be causing the low compression. Refer to the appropriate Workshop Manual, Engine System, General Information, 303-00.
If low compression is found in a cylinder that did not have a misfire detected then proceed with normal base engine diagnostics per the Workshop Manual, Engine System, General Information, 303-00.
If the exhaust valve is identified as the source, replace both cylinder heads with the newly released service cylinder heads. Refer to the appropriate Workshop Manual, Section 301-01A.
Cylinder Head Assy.
Upper Gasket Kit
Cylinder Head Bolts
Engine Exhaust Gasket
Valve Cover Gasket
China Gasket (Front)
China Gasket (Rear)
Gasket-Upper Intake Manifold
Eligible Under Provisions Of New Vehicle Limited Warranty Coverage And Emissions Warranty Coverage