Hi All, I could use some help with some results of oil samples from a survey. I am very close to buying a 1981 53 Hatteras MY with only 900 hours on the motors (a grocery getter basically). Brief background is that the boat is in amazing condition, got a rave review in the general pre-purchase survey, the owner lives in Asia and has spent 2 weeks aboard per year over the last 12 years and may take her out once or twice during that time. She shows “like new” above and below deck. The boat is professionally managed, upgraded and cared for with calculated maintenance if it was needed or not. I am NEW to diesel motors... The last 12 years I’ve owned a Chris Craft Commander 392 which is gas... I have gotten some of the oil samples back from the lab as part of the due diligence of the purchase. -The starboard motor came back green lights and no issues. -The generator test came back as: SODIUM LEVEL IS HIGH. NO GLYCOL/WATER DETECTED AND MAY BE BURNING OFF IN THE COMBUSTION PROCESS. ALL OTHER ANALYSIS READINGS APPEAR NORMAL. MORE SAMPLE HISTORY NEEDED TO ESTABLISH A NORMAL WEAR TREND. MONITOR FLUID LEVELS/USAGE CHANGE OIL AND FILTER(S) AND RESAMPLE IN 100 HOURS TO MONITOR. My brain thinks this is because the genny is just not run...My experience is that generators need to be used consistently to run clean and run well. -One of the transmission reports came back as: IRON IS ELEVATED AND MAY INDICATE GEAR / BEARING WEAR. ALL OTHER ANALYSIS READINGS APPEAR NORMAL. MORE SAMPLE HISTORY NEEDED TO ESTABLISH A NORMAL WEAR TREND. INSPECT ANY MAGNETIC PLUG(S) FOR DEBRIS. CHANGE OIL AND FILTER(S) AND RESAMPLE IN 10 HOURS TO MONITOR. Here I have no clue what to think, no experience... The mechanic told me that also it’s because the boat is not run. Two more tests will come back this week for the other engine and tranny. Also, I should share that they are Detroits...8V71TI’s with Allison’s. Any thoughts or feedback from any of you more experienced salts? Thank you.
What is the sodium level on the generator in PPM? What is the iron level on the gear? How many hours are on the oil? Without that what you're saying is useless. Generator most likely needs a new heat exchanger......but we need the actual levels. Why have you only gotten some samples back, they're usually all run at the same time.
Thanks for the reply Capt J. Sodium level on the generator is at: 200 Iron level on the gear is at: 176 Engine oil was changed recently within the last 45 days, however I am unsure about the generator and transmissions. I am going to find out. Great question about the missing samples. I also scratched my head. All I heard upon inquiry is that the lab must have misplaced them. So, the mechanic re-sampled and should get the updated results this coming week.
Both samples are high, but not OMG high. The problem is your just don't know. On both I would change the oil, and sample again at 20 hours and see where they're at. The location the generator is in shouldn't ingest salty air, but you don't know.....could be a heat exchanger there or perhaps hasn't been changed in a very long time. The gear is a bit high, but a lot of times people never change the oil in the gears.....ZF calls for 1000 hours but has no time limit for example......I do them every 2 years on the yachts I manage.
Sounds like condensation in a salt environment. Lack of use will cause this. Fresh service with hours after, will be the next oil test. Sadly, you may not get these test in time unless you run for a while at sea trials and test again when hot and back at dockside. There is usually a DD 71 tech somewhere close. Parts are around. Allison techs are getting harder to find. Most clutch parts and seals are still available. larger parts are used. Ask around thru your cruising areas. With that low of HP, there should not be problems with the clutch, but,,, it's a boat. Gen-set is probably an Onan MD4-20Kw. If it's running fine, then good but has no value. Just remember; there are no more big or cast parts available for the MD4. I was about to order a head gasket kit this past summer; It's was in Bolivia. professionally managed, upgraded and cared for with calculated maintenance if it was needed or not. calculated is pronounced budget in south Georgia.. Not is usually the outcome. Survey the heck out of all with your surveyors.
Hi All... Further to this posting, I have some additional info from the oil sample results and would like your two cents if you don’t mind. Concerning the generator: The oil on it was two years old and in this time, there was probably only around 4 hours on it. Also, the sample was taken cold at the oil filter. With this info, do you think the theory of lack of use illustrating the higher sodium level (200 ppm) holds water? Since then, the oil has been changed and will re-sample after some hours of use. Concerning the gear oil: Same thing...It’s been even longer since the oil has been changed, however minimal hours on them. Again, the sample was taken cold at the filter. Any additional thoughts to an elevated iron level (176 ppm) from what you’ve already given feedback? Also, the oil has now been changed and will re-sample after some hours. I was informed that taking samples cold and at the filter is the dirtiest spot to sample, so it’s in turn the best spot to get a read? I am scheduled to close on this vessel in two weeks and just want to make sure there aren’t OMG red flags. My instinct is to go for it and just keep an eye on it given the overall condition and care of the boat that has been given to her. Again, I am new to diesel motors, hence the rookie questions. Thanks fellas.
Yes, the age of the oil gives a high probability that it is just old oil. At least with the gear, iron is usually caused by internal rust and if the oil is that old and boat used that little, from condensation in the gear. The generator is a wild card....monitor it and see what the oil sample reads after running it 24 hours or so.....worst case scenario is it is probably the heat exchanger or exhaust riser. Given it's age, I'd recommend changing the heat exchanger and exhaust riser on the generator when you buy it, or best case scenario is to just budget to replace the entire generator when it goes.
That is good news. Good equipment. Not the Oh No gen-set I thought it could be. There were cast iron exhaust riser issues with the original equipment. NL released a new design made of bronze. Make sure your surveyor looks this over well.
