I sent my oil out to be analyzed and one of the engines showed high iron. The other engine was normal. The engines have 1500 hours on them and are serviced regularly. What does high iron mean and what is the typical life span (in hours) before these 1994 Cummins 6BTA will need overhaul?
Greetings Amnesia, Welcome to YachtForums. Have you been regularly sampling your oil to have a timeline, or is this a one-time snapshot? Oil analysis is most useful over a period of time with regular sampling. One sample may not mean too much. Was there a recommendation from the lab for action? Is the engine behaving well otherwise? Without more info, I would encourage an oil change (if you haven't already) and sample again after 50 hours. I have experienced a situation where we determined that there were apparently contaminated oil samples. We re-tested the same oil and have gotten clean results. If that same oil is still in the engine, you may want to run another sample through testing.
That was the first time oil sample I ever took. I noticed diesel soot around exhaust ports more than usual and the engines still smoke a bit even after coming off plane, never did that before. Smoke is blueish. Nothing major, just noticeable to me. I've owned the boat 12 years. I ran some Lucas diesel additive to the oil. I heard good things about this product on older diesels. The lab report picked that up as well (high viscosity). Didn't change anything.
It's been my experience that it is best to adhere to the manufacturer's recommended general service intervals, to include specified lubricants - to the letter. The smaller displacement diesels are cranking out some pretty high HP. I would keep the oil pure, change it on schedule and run the lube oil that Cummins suggests. Makes sense to re-test the suspect sample.
To answer your question. High iron is rust, usually caused by condensation or moisture in the engine/oil. If high iron is combined with a high sodium reading, then you have saltwater getting in there. How many PPM was the iron content? How many hours and years on the oil? How often are the engines run?
you should change the oil and retest after putting some hours on the engine. record the engine hours, fuel used, type of use type and brand of oil used, and if any oil was added between oil change and sample. I would have a Cummins tech come down and address the smoke and leak. Iron, in addition to rust could mean wear from liners, camshafts, crankshaft, valve train, timing gears. Im not sure, but maybe rings? which could be the reason for some visible smoke and soot. viscosity can flux for a number of reasons including, fuel or coolant in oil or from recently adding or topping off oil before sample, or use of an additive. Also, i think at 1500 hrs, there should be alot of life left in 5.9 Cummings in a twin 40' express
As stated, the single oil sample is fairly meaningless on its own, however combined with the soot and blue smoke it's more telling. I agree with RT46. You didn't say if the soot and smoke are just from that one side or equal. Your hours/years works out to about 100 hrs. per year which is minimal, and I'll guess it wasn't put on equally which means it's probably sat for some extended periods. Motors don't like to sit. I've read that our engine (Yanmar) could see a life of 40,000 hours in continual service. Average recreational use of 200 hours a year should give it a lifesman of about 2,000 hours. Ours got 250 hours in 8 years. We just rebuilt it due to a valve breaking which was attributed to corrosion. I'd be inclined to pull the valves and inspect or at least scope, although corrosion may not be evident to the eye even. In any case I would not wait through another oil change before investigating.
We'll, I started her up for the first time this year and took her out for a sea trail. Port engine running 20 lbs of oil pressure at load and at idle. I checked the redundant guage on the engine and it said the same. Also noticed what I think to be "blow by" coming from the engine compartment. This is the same engine that had tested high iron in oil sample.
Blow by as in crank case gasses or steam? How old is the oil again and how long since last time a load was put on her? How does the exhaust gasses look?
I had the same cummins in a Tiara, do the same blowby in the engine room. The motors were low houred and ran great. Cummins said the blowby was normal on these engines and there was a way to route the Exhaust gas bypass into the intake and do away with the blowby in the engine room.
I think they were the 330 hp 6BTA's. I forget rpm's, but it made what it was supposed to at top rpm's. Call Cummins and run through your problem with them, but they stated it was normal, and there was a way to route the open breather to the air intake to solve the engine smokiness. The engines had around 1000 hours on them.
