Oil & Fluid Service

Diesel Truck Oil Changes& Fluid Service in San Diego

Preventive maintenance starts with clean fluids. LTEK provides OEM-spec oil changes, coolant service, transmission fluid exchange, DEF, and differential service for all major diesel truck platforms. We use the right fluids for your engine — not generic one-size-fits-all products.

Fast turnaround. Fleet volume pricing available. Every oil service includes a visual multi-point inspection at no extra charge.

Fluid Services
Engine Oil & Filter Change
OEM-spec oil (CK-4/FA-4) and filters. Cummins Fleetguard, Donaldson, Baldwin — matched to your platform.
Coolant Service & Flush
Extended life coolant (ELC) flush and fill. SCA/DCA additive testing. Thermostat and water pump inspection.
Transmission & Differential Fluid
Allison TES 295/389, Eaton PS-164, and OEM differential lube. Filter replacement included.
DEF Fill & Quality Check
API-certified DEF. We check concentration levels to prevent DEF quality fault codes and aftertreatment derates.
OEM Fluid Specs
CK-4 / FA-4FleetguardTES 295ELC CoolantAPI DEF
45 min
Avg Oil Change Time
OEM
Spec Fluids Only
FREE
Multi-Point Inspection
Fleet
Volume Pricing
Why OEM-Spec Fluids Matter

Wrong Oil = Expensive Problems

Modern diesel engines are precision machines with tight tolerances. Using the wrong oil viscosity, wrong coolant chemistry, or low-quality DEF can cause accelerated wear, aftertreatment failures, and voided warranties.

Cummins requires CK-4 or FA-4 rated oils. Allison transmissions need TES 295 or 389 approved fluids. Detroit engines have specific ELC coolant requirements. We know what goes in every platform — and we use exactly that. No shortcuts.

What's Included with Every Oil Change

More Than Just an Oil Swap

Every oil change at LTEK includes a complimentary multi-point visual inspection:

Belt & hose condition Coolant level & condition Air filter inspection Visible leak check Tire condition Brake visual check Light & reflector check DEF level verification
Oil & Fluids FAQ

Common Questions

How often should I change the oil on my diesel truck?+

Most diesel trucks need oil changes every 15,000–25,000 miles depending on the engine platform, oil type, and operating conditions. Cummins X15 with CK-4 oil can go up to 25K. Stop-and-go city driving or heavy loads may require shorter intervals.

What type of oil do you use?+

We use OEM-specified oils only — CK-4 or FA-4 rated depending on your engine platform. We match the oil viscosity and specification to your manufacturer's requirements. No generic bulk oil.

Do you offer fleet oil change pricing?+

Yes. Volume pricing for fleets with 5+ trucks. We can also set up scheduled PM programs with automated reminders so oil changes happen on time, every time. Learn about fleet programs →

Can bad DEF cause aftertreatment problems?+

Absolutely. Contaminated or diluted DEF is one of the most common causes of aftertreatment derates. We use only API-certified DEF and can test your existing DEF concentration to verify it meets the 32.5% urea spec.

Due for an Oil Change? We Use the Right Stuff.

Diesel truck oil changes and fluid service in San Diego. OEM-spec. Fast turnaround.