Description
The CM838929A is a marine-grade aluminum pencil anode designed to protect internal engine cooling passages from galvanic corrosion. Installed inside the engine’s cooling system, this anode sacrifices itself to protect critical components such as heat exchangers, oil coolers, and water jackets.
Aluminum construction provides longer service life and broader protection range than traditional zinc, making it ideal for saltwater and brackish applications.
Key Features
- Direct replacement pencil anode
- Marine-grade aluminum alloy
- Protects internal cooling system components
- Extended lifespan vs zinc
- Threaded design for secure installation
- OEM-style fit and performance
Engine Compatibility
Fits various:
- Volvo Penta gasoline and diesel engines
- Engines using pencil-style internal anodes
Common on:
- Heat exchanger–equipped engines
- Closed cooling systems
Serial Number Fitment Notice
Always confirm:
- OEM reference: 838929 / 194
- Thread size and length
- Engine model and cooling system configuration
Proper fitment is critical for correct protection and sealing.
When This Part Needs Replacement
- Anode is 50% or more consumed
- Heavy pitting or uneven deterioration
- During routine cooling system service
- Annually in saltwater applications
Installation Notes
- Remove plug and replace anode in housing
- Use thread sealant if required (non-insulating)
- Do not overtighten
- Inspect regularly (especially in saltwater use)
Alternate / Cross-Reference Part Numbers
- Martyr: CM838929A
- Volvo Penta: 838929
- Also referenced as: 194
- Zinc equivalent available
- Magnesium version available for freshwater
Parts Desk Insight
Pencil anodes are one of the most overlooked maintenance items—but they protect some of the most expensive parts of your engine. If these are gone, corrosion starts inside where you can’t see it, often leading to costly heat exchanger or cooler failures.
Shipping
Shipping: Ships same or next day for fast Canada wide shipping.
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