Caterpillar C18 ACERT Marine Diesel Engine Heat Exchanger Plates, Gaskets & Seals
Precision-engineered replacement plate packs, gaskets, and seals for CAT C18 ACERT marine propulsion and auxiliary engines — built for efficiency and endurance.
Caterpillar C18 ACERT Heat Exchanger Gaskets, Plates & Seals
The Caterpillar C18 ACERT is an 18.1-liter, inline 6-cylinder diesel engine that powers some of the most demanding marine and industrial applications worldwide. Designed for high performance and durability, it produces between 454 and 1136 bhp (339–847 kW) at 1500–2100 rpm and complies with EPA Tier 3, IMO II, and EU Stage V emissions standards.
At the heart of its cooling system lies a separate-circuit, shell-and-tube heat exchanger, which transfers heat from the closed-loop jacket water coolant to raw seawater. MechPro supplies OEM-equivalent titanium or stainless plates, rubber gaskets, spacers, bolts, and seal kits for all C18 and C18 ACERT configurations. Each component is built to withstand corrosion, vibration, and extreme thermal cycles for long-lasting performance.
Whether for commercial propulsion, auxiliary power, or offshore industrial systems, our replacement parts are precision-engineered to meet Caterpillar’s exacting standards.
To Schedule Parts & Service Today
Call 1 (800) 249-6709 or Use our RFQ Form

C18 ACERT heat exchanger shipped to MechPro for inspection and cleaning.

C18 ACERT heat exchanger parts and service.

C18 ACERT marine heat exchanger repair service.

C18 ACERT heat exchanger plates in refurbished unit.

C18 ACERT marine heat exchanger parts assembly scheme drawing.
Why Choose MechPro
- Worldwide Shipping – Fast and reliable delivery of all Cat® marine heat exchanger parts.
- Genuine & Aftermarket Options – OEM-spec compression, heat tolerance, and installation compatibility.
- Expert Support – Send us your serial number, part code, or image for instant identification help.
- Trusted Supplier – Over 15 years of heat exchanger service expertise across marine, refinery, and power generation industries.
Precision-Engineered for Reliability
Long-term durability, high fuel efficiency, simplified service, and long-life-to-overhaul — Cat® marine engines are designed for maximum productivity and minimal downtime.
A consistent maintenance schedule extends your Caterpillar engine’s lifespan and performance.
MechPro supports that mission by providing exact-fit heat exchanger components built to OEM specifications.

MechPro supplies C18 ACERT heat exchanger gaskets

Refurbished C18 ACERT heat exchanger boxed and ready for delivery.

MechPro refurbishes C18 ACERT marine diesel engine heat exchangers.
Caterpillar C18 ACERT Heat Exchanger Parts List
(Representative parts; verify by serial prefix or arrangement number. Contact MechPro for exact compatibility.)
| Part Name | Caterpillar Part Number (Example) | Description |
|---|---|---|
| Plate – Heat Exchanger | 358-7063, 358-7071 | Stainless or titanium plate for shell-and-tube exchanger |
| Gasket – Plate | 6N-4083, 7E-4642, 4N-7825 | Rubber or nitrile gasket for coolant-seawater isolation |
| Seal – O-Ring | 1P-3706, 8M-4991, 9X-8258 | O-ring seal for housing and pipe joints |
| Spacer – Plate Pack | 9M-9801, 8N-9679 | Spacer to maintain plate compression and alignment |
| Bolt – Assembly | 5M-2904, 7X-0840, 6V-7078 | High-tensile stainless bolts for exchanger frame |
| Collar – Locating | 1N-3802, 3B-4512 | Alignment collar for internal assembly |
| End Cover – Housing | 9N-9845, 6I-4356 | Front and rear cover for exchanger body |
| Gasket Kit – Complete | SEBP4246-012, SEBP5243-022 | Full gasket and seal kit for C18 ACERT heat exchanger |
| Liner – Coolant Tube | 327-1099, 327-1105 | Tube liner for corrosion and wear resistance |
Detailed assembly drawings available from Caterpillar publication SEBP4246. MechPro can supply vector-labeled diagrams and parts breakdowns upon request.
Product Overview
Heat Exchanger Gaskets
Create a tight, leak-free seal between exchanger plates. Essential for efficient operation and fluid isolation.
Heat Exchanger Plates
Precision-engineered titanium plates maximize heat transfer efficiency, ensuring consistent cooling for C18 ACERT engines.
Heat Exchanger Seals
Durable elastomeric seals prevent leaks at joints and maintain proper pressure within the system.
Together, these components sustain optimal engine cooling performance, prevent overheating, and extend engine life.
CAT C18 ACERT Engine Specifications
| Specification | Details |
|---|---|
| Configuration | Inline 6, 4-stroke-cycle diesel |
| Displacement | 18.1 L (1106 in³) |
| Bore × Stroke | 145 mm × 183 mm (5.7 in × 7.2 in) |
| Power Range | 454–1136 bhp (339–847 kW) |
| Rated Speed | 1500–2100 rpm |
| Aspiration | Turbocharged & Aftercooled (SCAC System) |
| Cooling System | Heat Exchanger or Keel-Cooled |
| Governor | Electronic (ADEM A4 ECM) |
| Fuel System | Electronic Unit Injection |
| Rotation (Flywheel End) | Counterclockwise |
| Emissions Compliance | EPA Tier 3, IMO II, EU Stage V, China II |
| Dry Weight | ~4,000 lb (1814 kg) |
| Dimensions (L×W×H) | 73″ × 44–47″ × 47–51″ |
Request a Quote
Whether you need a single gasket or a full heat exchanger rebuild kit, MechPro can help.
📞 Call: 1 800 249-6709
📧 Email: [email protected]
Or simply use our Request for Quote form to send us your engine model and photos of the exchanger — we’ll handle the rest.
C18 ACERT Heat Exchanger System Overview
The C18 ACERT uses a Separate Circuit Aftercooling (SCAC) configuration. This system includes two independent coolant circuits:
- Jacket Water Circuit (JW): Maintains cylinder block and head temperature.
- Aftercooler Circuit (SCAC): Cools intake air via a dedicated seawater-cooled heat exchanger.
Heat Exchanger Function:
- Transfers heat from the hot engine coolant to cooler seawater
- Keeps engine operating within a safe temperature range
- Prevents seawater from contacting internal engine components
- Uses corrosion-resistant plates and gaskets for longevity
Benefits:
- Prevents overheating under sustained load
- Improves fuel efficiency and performance stability
- Extends service life of seals, pumps, and coolant system components
Maintenance Recommendations
Proper heat exchanger maintenance prevents costly engine downtime:
- Inspect and clean heat exchanger plates every 1,000 hours or annually
- Replace gaskets during each disassembly to maintain seal integrity
- Flush seawater side after extended operation to remove scale and debris
- Monitor coolant quality and replace per Cat ELC service interval
- Check raw water pump for wear and impeller condition
Frequently Asked Questions (FAQs)
Q: How often should the C18 ACERT heat exchanger be serviced?
A:It’s recommended to inspect and clean every 1,000 operating hours or once per season for marine use. Gaskets should always be replaced when disassembled.
Q: What are common signs of a failing heat exchanger or oil cooler?
A: Symptoms include engine overheating, oil in coolant, or loss of seawater flow. These indicate possible gasket failure or internal corrosion and should be addressed immediately to avoid major repairs.
Q: What are signs of a failing C18 heat exchanger or seawater pump?
A :Indicators include rising coolant temperature, reduced seawater discharge, leaks at gasket joints, or oil/coolant cross-contamination. Early diagnosis prevents engine overheating and component failure.
Q: Do most CAT C18 ACERT Marine Diesel Engines use a shell & tube heat exchanger or a plate heat exchanger?
A: Most Caterpillar C18 ACERT marine engines use either a shell and tube heat exchanger or a titanium plate heat exchanger, depending on the specific configuration (e.g., propulsion, auxiliary, or generator set). For heat-exchanger (HEX) cooled engines, shell and tube is common, while plate heat exchangers are also used, sometimes with integrated fuel coolers.
Shell and tube heat exchanger
- This is a standard component for many HEX-cooled C18 configurations.
- It is often used for both the separate circuit after-cooling (SCAC) and the jacket water (JW) cooling systems.
Plate heat exchanger
- Plate heat exchangers are also used, particularly for a compact design.
- These can sometimes have the aftercooler and an integral fuel cooler combined into one unit.
Which one is used?
- Check the specific engine model: The type of heat exchanger depends on the engine’s intended application (e.g., propulsion, generator) and the specific model’s configuration.
- Look for “HEX-cooled” or “plate heat exchanger”: The documentation for a specific engine will specify whether it is heat exchanger (HEX)-cooled or keel-cooled. If it is HEX-cooled, check for details about whether it is a shell and tube or a plate-style exchanger.
Disclaimer
All manufacturer names, part numbers, and product descriptions are provided for reference and identification purposes only. Caterpillar®, CAT®, and associated model names and numbers are registered trademarks of Caterpillar Inc.
MechPro is not an authorized dealer for Caterpillar Inc. and is not affiliated with the company. Our inventory is constantly changing and may include both genuine OEM parts and high-quality aftermarket replacements. Unless explicitly stated, we do not guarantee that a listed item is manufactured by the original equipment manufacturer.
Product images, diagrams, and specifications are for reference only and may not exactly match the item shipped. Customers should use original part numbers to verify compatibility and determine the most suitable replacement for their needs.
