Judge engine age when the odometer is in question?

[Qaxe]

Has anybody ever used a service such as Oelcheck to determine the approximate mileage of a vehicle based on your motor oil?

My K6 reads 11,480 miles but there's no way in Perdition that is so. My bike runs, but it's certainly not 11k miles old...maybe 111k miles old. My engine came from a parts bike which had sat for years and years. I think that Tutankhamun was the last owner. My gauges came from the same parts bike as the engine, but again, there's no way my engine is that young. My compression is 125psi across the board, so it's no Spring chicken.

Odometer aside, I read something about testing engine oil to determine engine age, and wondered if it was real or fake. Has anyone here had any experience which such things? Have you or anyone you know tried it? If so, do you recommend it?

 

[brettp]

If the oil is changed, even once, they can't tell at all. Oil additives, valve adjustments, me piston rings, etc. would change whatever they are measuring. Sounds like BS to me.

 

[dirtdigger]

They can tell you what types of metals are in the oil. This can give you an indication of age....different metals and the PPM of the metals can tell you what is worn or what is wearing at a higher rate than it should. Different amounts of metals can indicate higher mileage or lower mileage etc.

 

[brettp]

Ok, I had to look this up to see what they promised. This analysis is similar to what Blackstone Labs does (I've used them before). They are analyzing the lubrication (oil) only. They measure oil additives, metals, etc. of the oil to tell you how often to change the oil. An engine that is putting more metals into your oil needs oil changes more frequently. Some other metals can indicate coolant in your oil. This quote is directly from their page: "The aim is: extending the operating time of the lubricant and the service life of the machines."

 

[Qaxe]

Thank you. Even when I read things, I don't see all the details. That sounds reasonable about the metals. Basically, like with most sorts of testing, you get a piece of the puzzle on whatever you're working on. Like the test that told me that 35% of my DNA is Scottish, but can't say where it came from.

I'm turning my attention to Blackstone Labs now. I reckon it's good to know all you can. Free sample test kit and $35 for analysis. Sounds reasonable. Thanks again.

 

[brettp]

When I used them I determined I could change my oil every year instead of 6 months. Limited metals in the oil, oil additives were sufficient to protect the engine and it's components.

 

[Qaxe]

I could never get a clear idea on whether old CB750s could benefit from adding things to the fuel or oil. Everyone who told me "Use this product" was selling it. Heh.

 

[brettp]

I added some mystery oil to the fuel recently to lubricate the cylinder but it was unnecessary after all. I do add Berrymans to the fuel a handful of times a year to burn off carbon build up and keep things in good shape. Just my two cents.

 

[Qaxe]

Your 2 cents is well spent.
EDIT: I only knew about Berryman's parts cleaner. I was taken aback there for a minute.

 

[brettp]

Your 2 cents is well spent.
EDIT: I only knew about Berryman's parts cleaner. I was taken aback there for a minute.

Lol. Yeah, the carb and fuel system cleaner gets high marks from many mechanics.

 

[Qaxe]

Just small update. Blackstone Labs replied to my question:
"We typically like to see at least 500-1,000 miles driven on the oil
to provide the most accurate analysis."

In other words, I can't just let my bike sit here, I need to go riding.

 

[dirtdigger]

Just get it up to operating temperature so you get all the oil circulated and the metals in suspension in the oil if its old oil. If you put new oil in it then yes you will need to get some miles on it so the engine wear metal will appear in the new oil. When I buy used equipment it gets run to temp then sample taken to get a baseline unless it looks like new oil. In repair shops we took oil samples on engines that we suspected coolant....especially gm 4.3L engines with leaking intake gaskets. They got coolant in the oil and destroyed front main bearings half the time. If they came back with coolant trace we wouldnt do repairs as engine damage has occured. In over the road diesels coolant in oil meant sleeves leaking or cracked normally.

In bike engines I never bother with oil samples unless I hear a noise or compression or oil pressure indicates an issue as I just tear them down and inspect and rebuild because its no big deal to pull the engine for a full teardown.

 

[Qaxe]

You bring up some good points. My compression is 125-120-120-125, so I'm guessing that I do have a problem of sorts. Probably not going to be helped with an oil test I guess.

My original question was about dating the engine. In your experience, could one make a vague guess on mileage by measuring tolerances of internal moving parts and gauge the wear? Obviously external pieces get changed over time, but what about other parts? Just as an example, could you look at valves and say "Oh yeah, this thing has way over 11k miles." Or is it impossible to gauge becasue of the way different people ride their bikes? (Like... a hotrod who regularly does the ton, vs. a guy who just drives to work everyday?)

Thanks for your reply.

 

[dirtdigger]

As stated in my first reply it can indicated how worn parts of the engine are. Certain metals only show up with a lot of miles. Copper only shows when the bearings are worn out. High aluminum levels indicate piston wear or camshaft bearing wear in aluminum cylinder heads. etc. It can not tell you haow many miles, it tells you what metals are in the oil and how high the concentration is. This will tell you if you have excessive amounts of wear of certain engine parts. And yes driving habits and but to a bigger degree the maintenance practices greatly affect wear in an engine.

 

[Qaxe]

You did say that. I can't even blame my memory, it's written right there. But thank you for adding more info.
"Copper only shows when the bearings are worn out." Mechanics just know this sort of thing? Might be trivia to you, but that's quite amazing to me. So much to learn. Thank you again.