Change Your Mercruiser Engine Oil

Changing your Mercruiser engine oil is not as difficult as you might think. Having the right tools makes this job much easier.

Steps

  1. Read your Owners Manual and its Safety Precautions.
  2. In general, you need to change your oil every year or every 100 hours of use, whichever comes first.
  3. Visually inspect your engine and check the oil before starting.
  4. Make sure the prop has been removed and that no people or pets are near the stern drive or prop before starting the motor.
  5. Check for fuel or fuel vapors outside or in a well ventilated area to prevent Carbon Monoxide poisoning to people.
  6. Make sure your engine has a water supply before starting.
  7. Be prepared for spilt oil. Cover your floor and cushions with old towels or blankets.
  8. Start your motor and let it warm up. This will warm up the oil and make it much easier to suck it up and out of your dipstick tube.
  9. Turn the motor Off. After the engine has run long enough to reach operating temperature turn the motor off and let it cool for a few minutes.
  10. Remove the dipstick and thread the oil hand pump onto the end of the dipstick tube. If you are using an electric oil changer bucket hook up the hose to the tube and attach the pumps wires to the battery (red is positive and black is negative).
  11. Suck out your oil into a container. Mer cruiser dipstick tubes are also Oil Withdraw tubes. You can suck all the oil out of the engine through the dipstick tube. This requires the use of either a small hand pump (part 802899A1 Oil Pump which can be purchased online or you can buy a more expensive Oil Changer Pump/Bucket Assembly from a marine supply store (about $160.00 and up).
  12. Replace the oil filter.
  13. Use the correct filter wrench and remove the old filter. Turn it counterclockwise as viewed from the bottom end of the filter. In some cases the filter might be difficult to remove. This is usually because it had been over-tightened when installed. A good wrench and patience usually prevails but in some cases you have to drive a large screwdriver through the body of the filter to get it off.
  14. Once the filter is removed use a lint-free towel and wipe off and inspect the filter mounting area. Make sure that the old filter o ring has been removed from the engine.
  15. Compare the size and type of the threaded hole of the new filter to the old filter to make sure you have the correct type.
  16. Coat the o ring on the new filter with clean oil.
  17. Thread the new filter into place until hand tight.
  18. Use the filter wrench to tighten another 3/4 of a turn and no more! Over tightening the filter makes it very difficult to be removed.
  19. Look up your engine oil capacity in the owner's manual or on the capacity decal on the engine. Most inline 4 cylinder engines take 4-5 quarts. Most V6 engines take about 5 quarts. Most V8 small blocks take about 5 quarts and Big Block V8's can take up to seven quarts depending on the exact model.
  20. Fill the engine with the correct amount of oil. Newer Mer cruiser engines use a Color Coding System to locate and identify the oil fill cap and dipstick. Mer cruiser uses yellow to identify oil service points.
  21. Let the motor sit for 5 minutes before checking the level on the dipstick. This will allow the new oil to drip all the way down into the oil pan.
  22. Remember that the filter will hold some oil too.
  23. After you are done filling install your oil fill cap and perform a general inspection on the engine. Make sure the filter has been installed and that you have cleared the engine area of all rags and tools.
  24. Supply a water supply to the motor and start the engine.
  25. Immediately inspect the oil filter while the engine is running. Look for any oil leaks. Go to the helm and observe your oil pressure gauge for a proper reading.
  26. Let the engine warm up to operating temp.
  27. Turn off the motor and let it sit for 5 minutes.
  28. The manual that came with my mercruiser says to check the oil level with the boat "at rest in the water".
  29. Remove and wipe off the dipstick and check the oil level again.
  30. Add more oil if needed. In general one quart adds about 3/8" on the dipstick. This can vary from model to model, though.
  31. Clean up your mess and go boating!

Tips

  • The filter is filled with oil and when you remove the filter oil will drip everywhere. Have a few rags handy and place a couple under the filter as to catch any drip-age. Pout the filters oil into the bucket that you used to suck out the engine oil. Make sure to legally dispose of your old filter and oil. Most cities have a Disposal Center and some service stations will accept your old oil and filters for free.
  • Use good oil, it's worth the money.
  • Use OEM factory parts whenever possible.
  • Keep your bilge clean and free of oil. Observe all environmental rules, laws and regulations.
  • The engine oil can be changed with the boat in or out of the water.
  • Take note of the condition of your old oil. It can tell allot about how your engine has been performing. Does it smell like gas? Does it have white milky streaks? Should it be changed more frequently?
  • Never over-tighten a filter.
  • Use this opportunity to inspect all engine systems and to perform other scheduled maintenance items required.
  • Use your engine serial number when ordering filters and parts.
  • Log your change in your Owners Manual or vessels log book.
  • Use a black marker and write the change date on the filter.
  • Use factory parts. Use your engine serial number to order the correct parts.
  • Online help sites such as sterndrives.com can answer your questions and supply the parts.
  • You will need an oil filter wrench to remove and change your oil filter. There are two basic sizes of oil filters used depending on which model Mer cruiser engine you have. Most Mer cruisers use a standard Oil Filter Wrench. The only exception are some of the Mer cruiser V6 (4.3L) engines. If you have a V6 and the filter is threaded onto the block it should be a smaller diameter filter. The smaller diameter V6 filters require a smaller V6-type oil filter wrench. Both types of wrenches are sold at most auto supply stores and they are pretty cheap.
  • Read your Owners Manual. It's filled with good information.
  • Never install double o-rings. Make sure the old o-ring has been removed. Never reuse a filter. Once it's been removed it's junk.
  • Have all the proper tools and materials before starting the job.

Warnings

  • Use protective gloves.
  • Props are sharp and can injure or kill a person or pet. Remove your prop before running the engine on land.
  • Use protective eye-wear.
  • Fuel vapors can explode causing damage, injury or death.
  • Moving parts can injure or kill you. Always stay clear of moving parts such as pulleys and belts.
  • Have a fire extinguisher close by, just in case.
  • Oil is known to cause cancer. Do not get oil on your skin or in your mouth. Immediately wash off any oil with soap and water. Seek medical treatment if needed.
  • Always have an adequate water supply to your motor when running. Never run dry!
  • Warm engines can have hot spots which can severely burn you. Take care when working around hot engines to prevent burns.
  • Lead-Acid batteries can produce explosive hydrogen gas. Make sure the area is fully vented.
  • Carbon Monoxide is deadly poisonous and impossible to detect by sight or smell. Only run your engine outdoors and clear of any buildings where people might reside.
  • Use care in working around a hot motor. You can be burned.

Things You'll Need

  • Owners Manual (can be purchased at http://www.sterndrive-information.com)
  • Oil Filter Wrench (proper size).
  • Oil Changer Pump (hand or electric).
  • New Oil Filter (use engine serial number to look up).
  • Oil. Correct type and amount. See Owners Manual or decal on the motor.
  • RAGS, RAGS and more rags.
  • Water supply to motor.
  • Soap and Water.
  • Protective gloves.
  • Eye Protection.
  • Fire Extinguisher close buy.

Related Articles

Sources and Citations

Retrieved from "https://kipkis.com/index.php?title=Change_Your_Mercruiser_Engine_Oil&oldid=303598"