Exhaust leaks caused by calapsed exhaust manifold pipes on 34 IC units with PSI engines. they are wrapped with aluminium covering with insulation. This in turn makes high heat tempuraters that split and burn up and disfigure pipes. Which can cause a fire if any oil leakage or fuel occurs. It also has been snapping exhaust manifold bolts away from manifdolds.
The worst 2021 Ic Bus Cesb problems
Ranked by number of owner complaints. Mileage and cost come from what owners wrote.
- Engine2
- Fuel system1
Problems by type
Tap a problem to see which part fails, at what mileage and in which other years.
- Engine2
- Fuel system1
Recalls 4
Structure: body
- What is wrong
- International Motors, LLC (International) is recalling certain 2016-2026 IC Bus CESB and 2016-2021 RESB school buses. The underfloor reinforcement may not have been installed, compromising the structural integrity of the buses. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) numbers 210, "Seat Belt Assembly Anchorages" and 222, "School Bus Passenger Seating and Crash Protection."
- Risk
- Reduced structural integrity may increase the risk of injury in a crash.
- Remedy
- Dealers will inspect and install a reinforcement channel as necessary, free of charge. Owner notification letters were mailed December 8, 2025. Owners may contact International customer service at 1‑800‑448‑7825. International's number for this recall is 25514.
Recall number 25V580000 · Recall details
Service brakes, hydraulic: fluid
- What is wrong
- International Motors, LLC (International) is recalling certain 2016-2024 IC Bus CESB school buses. The brake pressure switch assembly may leak brake fluid into the brake pressure switch's electrical components and cause an electrical short-circuit.
- Risk
- An electrical short in the brake pressure switch can overheat the circuit and increase the risk of a fire while driving or parked.
- Remedy
- Owners are advised to park outside and away from structures until the recall repair is complete. Dealers will install a silicone black jumper harness, free of charge. Owner notification letters were mailed December 15, 2025. Owners may contact International customer service at 1‑800‑448‑7825. International's number for this recall is 25510. Vehicles previously repaired under 23V398 will need to have the new remedy completed.
Recall number 25V503000 · Recall details
Service brakes, hydraulic: fluid
- What is wrong
- Navistar, Inc. (Navistar) is recalling certain 2016 and 2018-2024 IC Bus CE school buses. The brake pressure switch assembly may leak brake fluid into the brake pressure switch's electrical components and cause an electrical short-circuit.
- Risk
- An electrical short in the brake pressure switch can overheat the circuit and increase the risk of a fire while driving or parked.
- Remedy
- Owners are advised to park outside and away from structures until the recall repair is complete. Dealers will replace the brake pressure switch assembly and if necessary, the wire harness or fuse, free of charge. Owner notification letters were mailed September 29, 2023. Owners may contact Navistar's customer service at 1‑800‑448‑7825. Navistar's number for this recall is 23518.
Recall number 23V398000 · Recall details
Engine and engine cooling: engine: engine control module (ecu/ECM)
- What is wrong
- Navistar, Inc. (Navistar) is recalling certain 2020-2023 IC CE school buses. The engine control module (ECM) may set a fault code that results in an unexpected engine shut down.
- Risk
- Unexpected engine shut down can increase the risk of a crash. Additionally, a disabled school bus may require an evacuation procedure in an uncontrolled traffic situation, increasing the risk of injury to passengers.
- Remedy
- Dealers will reprogram the ECM, free of charge. Owner notification letters notifying owners of the safety risk were mailed January 18, 2022. Owners may contact Navistar customer service at 1‑800‑448‑7825. Navistar's number for this recall is 21507.
Recall number 21V837000 · Recall details
Technical service bulletins for the 2021 Ic Bus Cesb 74
Bulletins tell dealers how to fix known problems. A warranty extension means the manufacturer pays for that repair for longer.
- This article provides guidance to dealership personnel, Technical Services personnel, Dealer Service...
- The purpose of
- Certain International® trucks and IC BusTM CE Series buses may have out of date BCM programing that may
- This document is for Diesel buses MY2020, MY2021, MY2022, MY2023, and MY2024 specifically built between...
- This document provides guidance for assessing the feasibility of implementing a customer-requested change...
- New CARB Idle Reduction Change Request
- This tool is designed to compare Diamond Logic feature data across multiple vehicle configuration files
- Engine replacements for all International engines will need to follow this procedure.
- This document will guide the user through a step-by-step procedure for detecting water leaks in vehicle...
- This article will guide the reader through steps to help gain a general understanding of the LPG Gen 1 and...
What 2021 Ic Bus Cesb owners say
Most recent owner complaints, unedited.
THis is a school bus- Exhaust downpipes leading into the catalytic converters melted down and created large holes in the exhaust pipe itself. Extreme heat developed by engine.
School buses. We have a fleet of these and the condition is happening repeatedly and to almost every bus with this PSI brand 8.8L gasoline engine. The engine exhaust downpipes melt from excessive heat and/or fuel. The pipes then crack and produce an exhaust leak near the body firewall. Potential for exhaust and flame to escape from the pipe.
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Questions about the 2021 Ic Bus Cesb
Is the 2021 Ic Bus Cesb reliable?
Owners have filed 3 complaints about the 2021 Ic Bus Cesb, 1.5 times a typical Cesb model year.
What is the most common problem with the 2021 Ic Bus Cesb?
Engine and cooling, with 2 complaints. Next is fuel system (1).
How many recalls does the 2021 Ic Bus Cesb have?
4 recalls, covering structure, service brakes, hydraulic and engine and engine cooling.
Was there a recall on the 2021 Ic Bus Cesb engine?
Yes, 1 recall: 21V837000. Check your VIN to see if your car still needs the free repair.
VIN decoder
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