Volvo Penta O-Ring 3583831 – Heat Exchanger / Oil Cooler Seal | D4 D6

Volvo Penta O-Ring 3583831 – Heat Exchanger / Oil Cooler Seal

Part Number: 3583831
Brand: Volvo Penta (OEM)
Product Type: O-Ring / Cooling System Seal
System: Cooling – Heat Exchanger & Oil Cooler Thermostat Assembly
Sold: Individually

The Volvo Penta 3583831 is a genuine OEM O-ring that seals the heat exchanger and oil cooler thermostat assembly on D4 and D6 marine diesel engines. It sits within a three-seal cooling stack alongside 3583830 and 3583832, and is most often serviced whenever that assembly is opened for any reason.

Compatible Applications

• Volvo Penta D4-180 through D4-300 (verify by engine serial number)
• Volvo Penta D6-280 through D6-480 (verify by engine serial number)

Cooling-system layout, heat exchanger version, and oil cooler configuration vary across D4 and D6 production runs. Always confirm fitment using your engine serial number and the applicable Volvo Penta cooling-system parts diagram before ordering.

Serial Number & Diagram Fitment Notice

Several O-rings in this cooling stack are similar in appearance but seal different positions (see diagram positions in the Volvo Penta D4/D6 Cooling System schematic). Match part number 3583831 to its exact diagram position for your serial range — do not rely on visual size comparison alone.

When to Replace

• Any time the heat exchanger, oil cooler thermostat housing, or adjacent cooling assembly is opened
• When the seal shows flattening, hardening, swelling, or signs of seepage
• During cooling-system service when the thermostat-area sealing group is already apart
• Do not reuse a previously compressed or heat-cycled O-ring — replace as a matter of course

Installation Notes

Clean the sealing groove thoroughly before fitting the new O-ring. Install dry or with a light film of clean engine oil to ease seating — do not use petroleum-based grease. Confirm the diagram position of each seal before reassembly to avoid transposing adjacent O-rings.

Service Interval

Replace any time the heat exchanger or oil cooler thermostat housing is disassembled, or when seepage or seal degradation is found during a cooling-system inspection. At the cost of this seal, replacement on every opening is the right call.

Kit Contents

1 × O-Ring 3583831 (sold individually)

Related Parts

• Volvo Penta O-Ring 3583830 – adjacent seal in the same cooling stack (replace together)
• Volvo Penta O-Ring 3583832 – adjacent seal in the same cooling stack (replace together)
• Volvo Penta Thermostat 3583827 – thermostat commonly serviced in the same assembly

Technical FAQ

Q: Can I reuse this O-ring if it looks undamaged?
A: No. O-rings that have been compressed and heat-cycled in a marine cooling system lose their sealing ability even when they look intact. Always fit a new seal on reassembly.

Q: Do I need all three O-rings (3583830, 3583831, 3583832) at once?
A: If the cooling assembly is already apart, yes. Replacing the full set of adjacent seals in one visit avoids repeat disassembly if a neighboring seal fails shortly after.

Q: How do I tell these O-rings apart?
A: By their diagram position, not by size. Match each part number to the exact location shown in the Volvo Penta cooling-system schematic for your engine serial range.

Parts Desk Insights

This seal is one of the most common mix-up points in the D4/D6 cooling stack — neighboring O-rings look nearly identical, and customers sometimes order the wrong one based on the removed part alone. The reliable fix is to match the part number to the diagram position rather than comparing by eye.

If a customer is only replacing one seal after a cooling leak, it's worth suggesting the full three-piece set: 3583830, 3583831, and 3583832. All three are low-cost, and returning to the same assembly for a second seal failure is a frustrating and avoidable service call.