PPT Question & Answer Forum

Question: I have a 1993 Mercruiser V6 with an Alpha Sterndrive. I live in the Midwest and have to deal with freezing temperatures every winter. Can I simply remove the drain plugs from the engine to prevent freeze damage or are there other items I need to be aware of?

Response: This is a common question we are faced with regarding if winterization and freeze protection are one in the same. The answer is that they are definitely two different things. Freeze damage prevention is encompassed by winterization however winterization includes other maintenance and storage items in preparation for over the winter storage. The following video will go through the draining and freeze protection portion of the process however the video does not outline the oil and gear lube changes.

1. Stabilizing the fuel system – Always try and avoid ethanol based fuels during usage but more importantly during storage. Use a fuel stabilizing product that will stabilize the fuel system for long term storage.
2. Install an Engine Flusher (Muffs) –  The engine needs to be run and brought up to normal operating temperature before removing the various drain plugs and hoses. Be careful when removing hoses and plugs as the water that you will be draining out will be hot.
3. Remove the circulating pump hose and visibly ensure that the pump drains completely.
4. Remove the plugs from both the port and stbd side of the engine block. **IMPORTANT** Make sure and use a small screwdriver or piece of wire to clear the drain hole after removing the plug. It is very common for the drain hole to be partially blocked with sand or debris that prevents complete drainage.
5. Remove the hoses from both exhaust manifolds and visibly ensure complete drainage from each manifold.
6. Remove the hose from the poser steering cooler and visibly ensure that it drains completely.
7. Reinstall the drain plugs and hoses.
8. Glycol Engine Flush – – Using an engine flusher along with Propylene Glycol antifreeze – – While the engine is still warm run it until you visibly verify that a consistent flow of  glycol is being exhausted. This will ensure that the engine is now full of glycol. This not only prevents freeze damage in the event that a small portion of water unknowingly remained in the system somewhere, but it also protects the internal cooling passages from corrosion.
9. Change the oil and filter
10. Inspect and replace the sterndrive water pump impeller if necessary
11. Drain and replace the gear lube

Winterization Video – Mercruiser 4.3L V6 w/ Alpha Sterndrive

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