Crankcase Oil Test ?

[chaco]

Now that I have learned that my engine was done in by ancient sea water
in the crankcase....the SeaDogs in the harbor asked me if I had my oil
tested during the survey
What is an oil test ?
Where do you get it done ?
What results are you looking for ?
And.....shouldn't this be part of a standard survey ?

My suggestion...DO NOT BUY A USED BOAT WITHOUT DOING AN OIL TEST !

Thanks for your help on this

 

[Geoff Johnson]

You can have a test run by these folks:

http://www.blackstone-labs.com/marine.html

My surveyor didn't even come close to the level of thoroughness that would have included an oil test. In fact, I found out after I signed the papers that the PO hadn't even changed the oil in three years. So far, however, my engine is running very smoothly.

 

[NateHanson]

That's pretty cool. I hadn't heard of that. At $20 it might be worth it when considering to buy. But is a single test useful? Sounded in their sample reports like they relied a lot on comparing current values to previous test values. Looking for changes from a baseline.

Anyone use these? Anyone know if a single test is informative? How important is it to know exactly how many hours since the last oil change?

 

[Emerald]

I've used engine oil analysis in the past and it is quite useful, even without a baseline. If you start off with a fresh (known) batch of oil and run it x hours/miles, and then check it, you can get a pretty good read on engine wear by different levels of contaminants e.g high carbon may be ring blow by. Used in conjunction with other things like compression test, leak down test etc. it can all give you an idea of what is going on.


-David
Independence 31
Emerald

 

[NateHanson]

Think it's useful in a survey, where you can't typically change the oil and run it for a known number of hours before testing?

 

[Seth]

Oil Analysis

In aviation, many plane owners routinely send out samples at each oil change-it is a great way to track the health of your engine.

There are many compnaies who do this-do a search-and they can give you instructions and costs.
S

 

[Emerald]

Yes, definatly can still be informative. First, ask how old the oil is before you request a sample to take for testing - just trying to get a more accurate answer. There are certain things like water contamination and the presence of metals which would be indicators of a serious damage condition.

If you hit your favorite search engine with a query on "engine oil analysis", you'll get a lot of informative hits.

Don't forget to start with your eyes and ears and nose when checking out an engine - how's it sound (knocks, rattles, whirs etc. especially as revs up and down), look - color of exhaust from start through warm up/ visual survey of engine and components etc, color/consistency/feel of oil, smell - burned oil smell in crankcase breather? These are just some of the first things as you approach it and familiarize yourself with an unknown engine.


-David
Independence 31
Emerald

 

[escapade]

oil testing sites

Truckers, farmers, & heavy equipment operators use oil analsis also. Their usage is closer than aircraft type and typically would be less costly. The only time I would say to not get this done is if your a good mechanic w/spare engine laying in your garage waiting for a new home! Will give a fairly good indication of whats going on inside the beast and how long you can go before a major overhaul. Even thoough we sail it's nice to have a reliable battery charger!
Have fun & sail fast
Bud E34 "Escapade"

 

[jmoses]

Major assumption

There's a major assumption here that when buying a boat and taking an oil sample for survey that the oil wasn't changed prior to the survey/oil sample.

As a rule, I don't take oil samples unless requested. Why? Most owner's who are savvy change their oil regularly and even if they aren't, will most likely change the oil prior to selling. This way the crankcase oil will look good to a prospective buyer and a semi-clueless surveyor. It's amazing how much deferred maintainance gets done prior to selling a boat!

I do inspect the crankcase oil and after being a marine engineer for 20 years and looking at thousands of gallons of oil I've learned what may contaminate oil. A simple smear test will reveal alot about oil - water, coolant and fuel contamination are high up there in problems. Of all the oil tests that I've done, rarely was there any metal wear problems that weren't detectable by taking the oil filter, cutting it open and having a look. That's were all the metal bits will collect after all. In addition, a magnetic drain plug is also helpful in collecting wayward metal bits. As for trivial amounts of metal in a test, you need trending analysis by taking samples at regular intervals, otherwise it's not tremendously helpful unless there are tell-tale issues (bad valve adjustment, blue smoke, strange noises, funky turbo, etc.), metal chunks visible or other problems. Changing your oil at least once a year or at regular intervals is the key!


In addition, looking around an engine room will tell me whether the owner has completed any regular maintenance. If I see the engine is covered in rust, the bilge full of crap (oil, rags, etc.), the Racors are full of crud and other basic items not taken care of, I can assure you the oil wasn't changed any time in the past decade either. Also, how easy it is to change the oil tells me whether it gets done regularly. If it's a real pain, I doubt it gets done on schedule.

Surveyor's prospective:

John M.