Diesel Engine PM for Heavy Trucks

The engine side of a heavy-truck PM centers on the oil and filter change, plus whatever an oil sample or a scheduled overhead (valve) adjustment adds to that visit. Capacities and intervals are not one number for every truck. They come from the engine manufacturer's documentation for that engine and the way the truck is run. This page covers the heavy-truck engine. For oil, transmission and hydraulic fluids across trucks, generators and marine engines, see engine oil, transmission, and hydraulic fluids.

What does a semi truck oil change cover?

An oil change on a heavy-truck diesel is more than a drain and refill. The technician:

• replaces the oil filter, and any additional or bypass filter the engine is built with;
• fills to the quantity and oil specification the engine manufacturer gives for that engine and its oil pan, then checks the level;
• looks at what came out: metal in the filter, a fuel smell, or milky oil each point somewhere specific;
• takes an oil sample, when the customer or the maintenance plan calls for one.

The capacity depends on the engine, and on some engines on the oil pan and the number of filters fitted. The engine pages below give each manufacturer's published figure with its source.

What does a diesel oil analysis tell you?

A lab report on an oil sample reads the engine in ways a visual check cannot:

• Wear metals, such as iron, copper, aluminum and lead, show which parts are shedding material.
• Contaminants point to a failure path. Coolant in the oil points toward a leak from the cooling system, fuel points toward the fuel system, and silicon (dirt) points toward the air intake.
• Oil condition, such as viscosity and oxidation, shows whether the oil is still doing its job.

One sample is a snapshot. The value is in the trend across visits on the same engine, so the result belongs in that engine's service record, next to the rest of the visit, where the next technician will see it.

Where does the maintenance schedule come from?

"What is the maintenance schedule for a semi truck?" has no single answer. Engine manufacturers publish service intervals by duty cycle, so the same engine can be due at different mileages depending on how the truck is run. Cummins, for example, sets the X15 oil drain interval by fuel economy band, and Detroit sets the DD15's by duty category. The engine pages quote those intervals where the manufacturer's document gives them. Blue Collar Parts does not set intervals of its own.

Engine pages

Each page gives a manufacturer's published specification, quoted from a named document, and what the service record should show. Most give the oil capacity; the Series 60 page gives valve lash.

• Cummins X15 oil capacity: oil change volume, drain intervals and overhead adjustment interval.
• Detroit DD13 and DD15 oil capacity: service fill for both engines and the DD15 valve lash adjustment interval.
• Cummins B6.7 oil capacity: standard and high-capacity oil pans.
• Volvo D13 and Mack MP8 oil capacity: oil change volume by oil pan and filter count.
• PACCAR MX-13 oil capacity: oil system capacity and the oil and filter interval by duty.
• Detroit Series 60 valve adjustment: intake and exhaust valve lash, and how to find your engine's setting.

Log the PM in Blue Collar Parts

The truck PM form in Blue Collar Parts has an Engine Oil & Filter section, where the technician records what was done and found. The finished visit becomes the service record the customer receives. See the semi truck PM checklist for the whole visit.

Preventive maintenance is not a federal annual inspection and does not establish regulatory compliance. This page describes engine PM in general terms. Use the engine manufacturer's current service documentation for the items to check, procedures, specifications and service intervals.