Cummins X15

Access a printable PDF copy at this link: Cummins X15 605 Engine.pdf

Customer Support

• The most up to date and complete information for your engine can be found on QSOL at quickserve.cummings.com
• To find your nearest Cummins authorized location, go to locator.cummins.com or call 1-800-CUMMINS (1-800-286-6467)
• Having the Engine Serial Number available ensures correct information. The engine serial number can be found near the top of the engine.

Storage

• Store with a full tank of fuel from a high volume fuel retailer to prevent condensation and microbial growth in fuel tank.
• Completing annual maintenance prior to storage will remove corrosive elements in the engine oil and potential microbes in the fuel filter.
• Monthly exercise prolongs engine life. A 30-40 minute drive is best. If driving is not possible, operate the engine until coolant reaches 150-F to recharge system batteries and lubricate internal components. In park, turn cruise control on, and use cruise set switch to enable fast idle.

Operation

• Engine warm up - operate with light throttle for 3-5 minutes.
• Engine cool down - allow 3-5 minutes before shutting the engine off after full load operation.
• The ISX 15 and X15 compression brake can produce up to 600 braking horsepower. Use caution if using compression braking in slippery conditions.
• Amber "check engine" light indicates the need to pull over as soon as it is safely possible. If the lamp is flashing, the engine will shut down within 30 seconds.
• A complete guide to dash lamps related to the engine is contained in Cummins Bulletin 4971518 which can be found on cummins.com/brochures.
• Fuel economy can be improved by using cruise control, reducing vehicle speed, keeping tires properly inflated, reducing weight, keeping air conditioning system charged and keeping the radiator clean.

Cooling System

Check cooling system level before each trip.

• All coolant should be tested for freeze protection and dilution at least twice per year. A refractometer (e.g. Fleetguard CC2806) is much more accurate than floating ball hydrometers.
• Coolant must be maintained according the chassis manufacturer's recommendation. Most recommend changing coolant at 5 years of service.
• When having your motorhome serviced, insist on using the coolant that was originally used by the chassis manufacturer or equivalent.
• There are many formulations of coolant. It is ideal to use the coolant formulation that the motorhome was originally filled with.
• Mixing coolant formulations can result in loss of protection of
  the engine and other components in the cooling system.
• All coolants used in the ISX15 or X15 must meet Cummins
  14603 or 14439 specification.
• Engine Coolant Formulations include:
• Older traditional Heavy Duty Coolants are typically green in
  color. These coolants require testing twice per year for proper
  additive (SCA) concentration. 3 way test strips are available
  from Fleetguard in 4-packs (CC2602A). Coolant filters may
  have chemical additives. Buying “blank” non-chemical filters
  and using liquid additives, if needed, is recommended.
• Fill for Life Coolants (example: Fleetcharge) are typically
  pink in color. These coolants require testing for proper additive
  concentration.
• Organic Additive Technology Coolants (example: Fleetguard
  Compleat ES OAT, Peak Final Charge, Shell Rotella ELC) can
  vary in color and may require addition of a chemical extender
  before the change interval is reached.

Fuel System

• Purchase fuel from high volume fuel retailers to avoid issues

with water or microbe contamination.

• Engines built since 2002 can use up to B20 biodiesel. Pre 2002

engines can use B5.

• It is best to avoid storing your motorhome with biodiesel.
• Cummins engines are designed to run on commercially

available diesel fuel without the need for additives.

• A biocide can help when fuels are prone to contamination

(black slime).

• Cummins Bulletin 3379001 on QSOL contains a comprehensive

explanation of Fuel Recommendations.

Air System

• Not maintaining your air system is the most expensive mistake

you can make.

• Change air filter based on chassis manufacturer time

recommendation or more frequently if operating in dusty
conditions.

• The air restriction indicator should not be solely relied upon for

air filter replacement.

• Loose or broken clamps, hoses, or piping can lead to dirt entry

into the engine requiring engine overhaul.

Oil System

Check oil level before each trip.

• The X15 requires 1-2 gallons of oil to move the level on the

dipstick from add to full.

• For normal engine operation, Cummins recommends the use

of a high quality 15W40 or 10W30 heavy duty engine oil that
meets the requirements of Cummins® 20086 specification (API
classification CK-4).

• API classification FA-4 engine oils are NOT recommended for

motorhomes.

• The use of synthetic oils is allowed but does NOT justify the

extension of the oil drain interval.

• Break in period oil changes are not required on Cummins

engines.

• Cummins engines are designed to run on commercially

available oils without the need for supplemental additives.
Cummins does NOT recommend or require supplemental oil
additives.

• Oil analysis can be helpful in detecting contaminants, but does

NOT justify extension of the oil drain interval.

Diesel Exhaust Fluid (DEF)

• Cummins engines built since 2010 require the use of DEF. DEF

equipped engines achieve greater fuel economy.

• DEF is non-toxic, non-polluting, and non-flammable.
• DEF fluid must meet ISO 22241-1 specification.
• For maximum shelf life (18 months) store DEF in a sealed

container at temperatures below 78F (26C).

• DEF will freeze at 11F (-12C) but will not degrade when frozen.
• DEF tanks and lines are designed to accommodate freezing.