838929 Zinc Pencil Anode for Volvo Penta D19 D21 D27 D29 D30 D31 D32 D40 D41 D42 2001 2002 2003 | JLM Marine

Zinc Pencil Anode for Volvo Penta D19 D21 D27 D29 D30 D31 D32 D40 D41 D42 2001 2002 2003

This zinc pencil anode is designed to protect critical engine components on Volvo Penta marine diesel engines, including the D-series (D19, D21, D27, D29, D30, D31, D32, D40, D41, D42) and 2001, 2002, 2003 models. It provides galvanic corrosion protection for oil coolers, intercoolers, and cylinder heads in saltwater and brackish water environments.

This aftermarket replacement directly replaces Volvo Penta OEM part numbers 838929, 804107, 800476, 858501, 3838499, as well as Sierra 18-6001 and GLM 12789, ensuring seamless fitment and reliable performance.

• Material: Zinc – optimized for saltwater use
• Thread options: 7/16 UNC and M8 for versatile installation
• Diameter: 15 mm

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

• 1 × Zinc Pencil Anode (OEM #838929)

Installation Guide

1. Ensure the engine is completely cool and the cooling system is depressurized before beginning work.
2. Locate the existing zinc pencil anode on the oil cooler, intercooler, or cylinder head (consult your engine manual for exact locations).
3. Use an appropriate wrench to carefully unthread and remove the old anode. Inspect the threads for damage or debris.
4. Clean the mounting hole and surrounding area to remove any corrosion or old sealant residue.
5. Apply a small amount of anti-seize compound to the threads of the new zinc anode to ease future removal.
6. Thread the new anode into the mounting hole by hand first to ensure proper alignment and avoid cross-threading.
7. Tighten the anode to the manufacturer's specified torque using a torque wrench (typically 15–20 Nm; verify in your service manual).
8. Refill the cooling system if any coolant was drained, and bleed air from the system per manufacturer procedures.
9. Start the engine and check for leaks around the anode installation points.
10. Inspect the anode regularly (every 100–200 hours or annually) and replace when more than 50% depleted.

Troubleshooting & FAQ

Q: How do I know if this anode fits my Volvo Penta engine?
A: Check the Compatible Engine Models table above for your engine model (D19, D21, D27, D29, D30, D31, D32, D40, D41, D42, 2001, 2002, 2003). Cross-reference the OEM part numbers (838929, 804107, 800476, 858501, 3838499) with your engine's parts list or service manual to confirm fitment.

Q: How often should I replace the zinc pencil anode?
A: Inspect the anode every 100–200 operating hours or at least once per season. Replace it when more than 50% of the zinc material has eroded. In saltwater or high-use conditions, more frequent replacement may be necessary.

Q: What are the signs that my anode needs replacement?
A: Visible erosion or pitting of the zinc material, corrosion appearing on nearby engine components (oil cooler, intercooler, cylinder head), or coolant leaks around the anode installation point all indicate it's time to replace the anode.

Q: Can I use this zinc anode in freshwater?
A: Zinc anodes are optimized for saltwater and brackish water environments. For freshwater use, aluminum or magnesium anodes are generally recommended. Consult your engine manual for the correct anode material for your operating environment.

Q: What is the difference between OEM and aftermarket anodes?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.