The right way to approach an International depends on when it was built. Navistar changed engine strategy several times over the last 25 years, and the trouble spots on a 2004 DuraStar have little in common with a 2012 ProStar or a new LT. RDI Power works on all of them, in our Brooksville bays and at fleet yards around the region.
Before 2010: DT466 and VT365
DT466 and DT466E
The DT466 earned its reputation in International 4700 and DuraStar 4300 trucks, school buses and farm equipment. Electronic DT466E engines use HEUI injectors fired by high-pressure engine oil, the same principle as the 7.3 Power Stroke. Oil condition, the high-pressure oil pump and injector O-rings drive most of their fuel system problems. Our fuel injection page explains how we test them.
VT365
The VT365 is Navistar’s version of the 6.0 Power Stroke, used in 4200 and 4300 trucks and in IC buses. It carries the 6.0’s weak points: oil cooler and EGR cooler failures, head gasket problems and sticking injectors. Our Power Stroke service page covers that family, and Alliant Power builds HEUI components we use on these engines.
The MaxxForce years
MaxxForce engines carried International from the 2007 emissions rules into the mid-2010s. The MaxxForce 7 is a sibling of the 6.4 Power Stroke, the MaxxForce DT followed the DT466, and the big-bore MaxxForce 11 and 13 were built to meet the 2010 rules with EGR alone, without SCR. That EGR-only approach produced a long record of EGR, cooling and soot complaints, and later trucks added SCR.
On a MaxxForce we test EGR cooler integrity, EGR valve operation, turbo actuators and sensor data together before trusting any single code. These engines punish guesswork, and a straight answer on whether a repair makes sense for the truck is part of the job.
Current Internationals
- LT and RH: on-highway and regional tractors, with the International A26, the newer S13 or a Cummins X15.
- HV and HX: vocational and severe-duty trucks for dump, mixer, utility and heavy haul.
- MV: medium-duty trucks, commonly with the Cummins B6.7.
- CV: Class 4 and 5 trucks developed with GM and powered by the 6.6L Duramax.
The A26 is Navistar’s 12.4-liter engine introduced for 2017, and the S13 is its newer 13-liter. Both run full aftertreatment with a DPF and SCR, so DEF quality, doser condition and NOx sensor agreement are routine checks. Our exhaust and DPF page covers that system.
IC Bus
IC CE school buses share engines and much of their engineering with International trucks, from older DT466 and VT365 buses to newer ones. We handle engine, brake, electrical and chassis work on them; see bus repair.
Electrical and body controls
Many Internationals run lights, wipers, gauges and upfit circuits through Navistar’s Electronic System Controller. A lighting or gauge fault on these trucks can be a wiring problem, a switch input or a programming issue, so we test the circuit before suspecting the controller. Humidity and road spray corrode chassis connectors, especially on trucks with years of local work behind them.
How we work an International
We start by confirming exactly which engine and emissions package the truck carries, because a MaxxForce DT and an A26 share almost nothing. Then we pull fault history from every controller, test under load, and confirm the cause with pressure, voltage and leak tests. Nothing is approved until you have seen the digital inspection and its photos.
International trouble signs
- Hard starts or long cranking on a DT466E or VT365, especially when warm
- Coolant loss, white smoke or coolant in the exhaust
- EGR or aftertreatment codes that return after clearing
- Oil level rising or dropping between services
- An IC bus due for its inspection
Send the VIN and any active fault codes. We will tell you what we need to see, and whether to bring the truck in or have a mobile technician start at your yard.