2010-emissions MaxxForce 11 and 13 coolant loss: refill history, verified leak path and core or assembly repair scope.

MaxxForce 11/13 Coolant Loss and Oil in Coolant

by Advanced Truck Parts on Oct 31, 2026 Categories: Parts & Maintenance

Back to the ATP Garage guide libraryInternational / MaxxForce 11/13 / Coolant loss and EGR cooler evidence

For oil found in MaxxForce 13 coolant, use the separately scoped oil-consumption branch and cleanup discussion below. Keep the confirmed fluid finding with the installed-engine and repair record.

Quick answer: On a 2010-emissions MaxxForce 11/13, repeated coolant loss without an obvious puddle needs a documented cooling-system diagnosis. Navistar's dated diagnostic separates external leaks, the pressure cap, overflow/temperature concerns and coolant reaching the exhaust, intake or oil. An EGR cooler is a possibility to test, not a conclusion from the engine name. [1]

Scope checked November 2, 2026: This guide uses the identified 2014–2015 Navistar bulletins, including their later retirement note for 2010-emissions MaxxForce 11/13 applications. Navistar explicitly removed N13 from IK1201066's applicability in April 2015. Confirm the installed engine and current service information; do not transfer this path to N13, A26, MaxxForce DT or DT466 engines. [1]

What should I record when coolant keeps disappearing?

Build a short history before the next service visit. Record the amount added, date, miles/hours, level-check conditions and when the concern occurs. Include recent cooling-system repairs and refill work. Navistar's cooling diagnostic flags improper refilling, an uncleared prior code and overfilling as history that can confuse the complaint. [1]

Keep an actual repeated refill requirement separate from a warning message with no verified loss. The general cooling diagnostic sends an isolated SPN 111/FMI 1 concern without coolant loss to coolant-level-switch circuit troubleshooting. [1] Give the shop both observations so the request does not become "replace the low-coolant part."

Photograph any accessible residue or wet area while the engine is stopped and safe to approach. Note whether the symptom started before or after the last repair. Avoid adding a guessed cause to the work order: "added coolant twice since Monday" is more useful than an untested component diagnosis.

Why do SPN 111/FMI 1 and SPN 2659/FMI 21 matter together?

The cited documents identify 111/1 as low coolant and 2659/21 as EGR low flow. When EGR low flow accompanies coolant consumption or the low-coolant code, the July 2015 version of IK1201066 referred technicians to IK1201100 first. That historical branch considered the combined complaint before returning to wider coolant-loss checks if needed. [1] [2]

Save the complete scan report, including active and historical status, before codes are cleared. Ask the technician which current procedure applies to that engine and combination of symptoms. A code number is useful evidence, but an online description does not replace the diagnostic findings needed for a repair.

Historical-source limit: IK1201113 revision 13, November 2, 2015, records a September 16, 2015 change removing its IK1201100 link because that article had been retired and integrated into the diagnostic manuals. The July IK1201100 copy here explains the dated reasoning; use the current matching manual and Fault Code Action Plan for the actual diagnosis. [4]

What if there is no visible external leak?

Ask the shop to document where coolant is going and which tests establish that path. The distinction matters more than a list of parts that other owners have replaced.

Observation to report	Ask the shop to document	Avoid this assumption
Repeated refill with no puddle	Inspection findings, applicable system/cap checks and the next diagnostic branch.	No visible puddle proves an internal engine failure.
Coolant residue or wetness	The traced source and how it was distinguished from old repair residue.	The nearest component is automatically responsible.
Smoke, odor or suspected contamination	What substance was actually confirmed and where it was found.	Appearance alone identifies an EGR cooler or head gasket.
Overflow or temperature complaint	When it occurs and the findings under the matching diagnostic.	A refill alone completes the repair.

Keep pressure testing, component isolation and disassembly with a qualified service provider using the applicable manual. Do not open a hot pressurized cooling system. If a stop-engine warning, overheating or suspected coolant contamination is present, follow the vehicle's warning instructions and arrange service rather than continuing a trial drive.

What should be checked before replacing a MaxxForce 11/13 EGR cooler?

Navistar's coolant-in-exhaust bulletin calls for testing the low-temperature (LT) and high-temperature (HT) EGR-cooler sections and identifying which section leaks. If neither leaks, it returns to cooling-system testing. It also directs oxygen-sensor diagnostics after confirmed coolant leakage to the exhaust; that is a follow-up diagnostic, not proof that the oxygen sensor has failed. [3]

The later November 2015 HT-core bulletin retains an important test distinction: residual air from HT testing can make the LT section appear to leak when the test setup is not handled correctly. A report of "both halves failed" therefore needs valid test results and procedure control. [4]

Before approving a cooler purchase, request the engine identity, procedure used, confirmed leak location and repair scope. Ask whether the finding concerns an internal section, an external leak or a different coolant path. Keep the answer with the estimate so the parts request reflects what was diagnosed.

IK1201113 revision 13, November 2, 2015, distinguishes a diagnosed internal HT leak, for which it describes a core-repair path, from external housing or joint findings with different repair scope. Its stated coverage includes 2010-emissions MaxxForce 11/13 and separately 2013 N13. That separate repair coverage does not restore N13 to IK1201066's cooling diagnostic. Have the current procedure establish the correct repair scope; do not convert every coolant-loss complaint into a complete-cooler order. [4]

Have the estimate name the tested section and distinguish a core or section repair from a complete assembly. Ask the installer to identify the required seals, hardware and follow-up service under the current instructions. Keep uncertain findings separate from confirmed repairs.

For the broader parts decision, read our EGR cooler leak and coolant-loss guide. Use this engine-specific article for the MaxxForce bulletin scope, and the broader guide for organizing evidence before ordering.

What if oil is found in MaxxForce 13 coolant?

Keep this finding separate from coolant disappearing, coolant in the crankcase or coolant reaching the exhaust. Record which fluid was confirmed, where it was found, oil use and previous cooling-system work. Ask the shop to match that evidence with the installed engine and current diagnostic.

Separate scope: This example uses the 2010 MaxxForce 13 application in Navistar IK1201050, revision 7, December 4, 2015. That oil-consumption document also lists MaxxForce 11 and N13; its N13 listing does not extend the different coolant-loss diagnostic above. [5]

Within that historical oil-consumption workflow, oil-use verification and an external-leak check precede step 3 on page 3, which inspects the coolant surge tank for oil. Its Yes branch directs oil-cooler replacement under the Engine Service Manual and cooling-system flushing under IK1201248; its No branch continues the oil-consumption investigation. [5] Have the provider verify the fluid finding and applicable current procedure before ordering a cooler.

Cleanup is a separate part of the repair. Navistar IK1201248, revision 7, January 3, 2017, describes a contaminated-system flush using a MaxxForce 13 demonstration. Its checklist accounts for the engine/radiator, heater circuits and applicable DEF, auxiliary-heater, APU and aftermarket circuits. It calls for hose-condition inspection and staged cleaning/rinsing; the final section addresses oil traces and oil-soaked rubber hoses. [6] Ask which installed circuits and affected components are included in the work order and how completion will be checked. Use current matched instructions for the actual equipment and cleaner; this guide does not reproduce the historical chemical, hot-fluid, pressurization or electrical-override procedure.

Before a parts quote: Keep the VIN, installed engine serial and emissions identity, fluid findings, oil-use record, prior repairs and the shop's diagnostic reference together. Confirm the exact cooler or other repair item and included seals, then agree the contamination-cleanup and final-verification scope. Broader fluid-identification questions are covered in our oil/coolant contamination guide.

What should I send before ordering MaxxForce 11/13 cooling parts?

Truck VIN, installed engine model and complete engine serial number.
Confirmed emissions generation, plus known engine or cooling-system changes.
Full SPN/FMI report and the actual coolant-loss history.
The technician's confirmed leak location and identified assembly or section.
Existing part/assembly markings and clear photos when safely available.
The quoted repair scope and the seals, hardware or other items it requires.

Match the diagnosed component

Use ATP's fitment request with those details. Request confirmation of the specific application and what the package includes. Do not order a cooler, sensor or cap solely because it appears in another truck's coolant-loss story. For a separate starting complaint, see the 2010-emissions MaxxForce 13 cold-start guide.

Common MaxxForce 11/13 coolant-loss questions

Is this the procedure for an N13?

No. The source's scope note excludes N13 from this cooling diagnostic. Obtain that engine's applicable information. [1]

Does a low-coolant code prove coolant is leaking?

Record the actual level/refill history as well as the code. A warning and measured consumption are different observations to give the shop.

Can recent service affect the coolant-loss complaint?

Yes. Include the repair and refill history in the work order; the cited cooling diagnostic specifically considers it. [1]

Does white smoke prove the EGR cooler failed?

No. Ask what confirmed the coolant path and which test identified the component. Do not choose a repair from the appearance alone.

Should both EGR-cooler sections be replaced together?

Have the shop explain the verified findings and current repair procedure. The dated bulletin distinguishes the sections and cautions about misleading test results. [4]

Is the July 2015 IK1201100 copy the current diagnostic?

The later IK1201113 change log says it was retired into the manuals. Use current matching service information; the archived copy explains a dated diagnostic distinction.

Does the December 2015 bulletin make every oily reservoir an oil-cooler diagnosis?

No. Its oil-cooler branch belongs to a defined oil-consumption workflow. Have the provider verify the fluid finding, installed application and applicable current diagnostic before selecting a repair. [5]

Is changing the cooler the whole contamination repair?

The cited flush document addresses affected circuits, hose condition and cleaning/rinsing after contamination. Ask the shop to include the installed circuits, affected-component decisions and final checks in the repair plan. [6]

Technical sources and application notes

These primary manufacturer documents support the stated examples. Dated bulletins explain diagnostic distinctions; the current service information for your engine controls the repair. ATP prepared this editorial guide; no independent technician review is claimed.