Home

Performing a valve job after diagnosing a misfire on a 2002 Mazda Tribute 2.0L

Oct. 14, 2015

Removing a cylinder and performing a valve job

Barry Hoyland

Vehicle Affected:

2002 Mazda Tribute 2.0L

Tools Used:

Vehicle specifications
Diagnostic worksheet
Scan tool
Vacuum gauge
Snap-On Compression Tester, No. MT308JB
Lab scope
Fluke Vacuum/Pressure Transducer, No. PV350
Matco Leak-Down Tester, No. CLT200

(This repair is diagnosed in the Tool Briefing: Diagnosing the root cause of a misfire)

Following the repair procedure outlined in AllData, we removed the cylinder head and had a valve job performed and the head surfaced. During the valve job it was noted that cylinder No. 4 had a significant amount of carbon build-up on the valve stems and valves. This information was valuable because it showed why there was a lower vacuum reading on that cylinder, it was lower because the air entering the cylinder was partially blocked by the carbon. Since we had a pulsation in the engine vacuum readings, we took extra care to make sure the valve springs were within specifications. We found the intake valve spring was weak on cylinder No. 2, which would cause the issue. After re-installing the cylinder head and replacing the ignition components due to wear, the engine ran well with no misfires.

About the Author

Barry Hoyland

Barry Hoyland has been in the independent aftermarket for more than 45 years as a technician, technician instructor, shop owner, and shop management consultant. He owned and operated a successful Southern California automotive repair center that offers complete auto care and specialized in emission and diagnostic services for over 28 years. Hoyland also owned a company that modified vehicles to perform as emergency response units and mobile command centers, incorporating high-end electronic components into today’s vehicles. Hoyland has experience with all size and types of vehicles including traditional gas, hybrid electric, alternative fuel, and heavy duty diesel trucks.

Hoyland has provided consulting services for many automotive shops, fleets, and government agencies in order to improve their operational efficiencies.

In addition, he has worked with many NHRA drag racing teams as a crew chief on supercharged alcohol and nitro-methane fueled cars and currently serves as a crew chief on a Top Alcohol Funny Car, a Nostalgia Funny Car, and a Nostalgia Alcohol Dragster

Hoyland holds certifications in ASE: A1, A6, A8, and L1, MACS 609, maintains a California Advanced Emission license, and a CDL with endorsements for double and triple trailers, tankers, and HazMat.

When he is not helping to run a shop in the Pacific Northwest, Hoyland travels across the U.S. as an instructor of technical and shop management courses, many of which he has developed.