Impeller pumps: Everything you need to know to replace or repair a wat

Impeller pumps: Everything you need to know to replace or repair a water pump!

Regularly replacing the coolant in your Volvo Penta engine is crucial. Failure to do so could result in cooling problems and costly repairs.

Coolant for Volvo Penta engines: Everything you need to know!

Which coolant should I use for my Volvo Penta engine? We get this question a lot at MarineDustrie . In this blog post, we'll tell you everything you need to know about the different types of Volvo Penta coolant , how to use it, how to replace it, and how often to change it.

Table of contents:
1. Why Coolant is Critical
2. What is coolant and what does it do?
3. How do I choose the right coolant for my Volvo Penta engine? -> Handy search tool
4. When and how often should you change coolant?
5. Step-by-step: Checking and topping up coolant
6. Overview per engine: correct type and capacity (liters)
7. Frequently Asked Questions (FAQ)
8. Safety, environment & warranty
1. Why Coolant is Critical
- Prevents overheating and cavitation
- Protects against corrosion (engine block, heat exchanger, pumps, pipes)
- Lubricates the circulation pump
- Increases boiling point and lowers freezing point
2. What is coolant and what does it do?
Base: water + ethylene glycol/propylene glycol

Additive packages: IAT / OAT / HOAT

OEM Specifications Volvo Penta (VCS/VOA: VCS-2 (Yellow) and Coolant-Ready-Mixed (Green) Non-OAT
3. How do I choose the right coolant for my Volvo Penta engine?
Always refer to the OEM specification on the nameplate/manual -> Refer to our search tool.
- Do not mix different coolants
- Color ≠ specification (color is an indication, but not binding)
- Environmental conditions: frost protection down to –25 °C / –36 °C
- Mixing ratio: 40/60 vs 50/50 (Volvo Penta coolants are ready to use and do not require dilution!
4. When and how often should I replace the coolant?
- Volvo Penta coolant should be replaced every 2-4 years
- Replace immediately in case of: rust/sludge, discoloration, unknown mix, or if you are performing maintenance on the cooling circuit
- Caution! Never mix two different coolants together. Mixing OAT and EG coolants can cause excessive sludge formation.
5. Step-by-step: Checking and topping up coolant
- Always check the coolant level when the engine is cold!
- Check expansion tank level (MIN–MAX)
- Refractometer/hydrometer: measuring freezing point
- Top up with the same specification and correct dilution
- Bleeding: open/warm up high points and recheck level
7. Frequently Asked Questions (FAQ)
Can I mix green and yellow/green coolant? → No, always flush when changing.
Is color the leading factor? → No, follow OEM specifications.
How do I measure freezing point? → Refractometer.
What if I don't know what's in it? → Use a full rinse and the correct specification.
8) Safety, environment & warranty
- Use collection container, dispose of old coolant as chemical waste
- Do not discharge into bilge or environment
- Please note the warranty conditions in case of incorrect specifications