Oil Analysis. How many miles on the oil before taking a sample?

[c good]

I'm planning on sending in an oil sample from my Envoy just to get an idea if there are any problems. I don't suspect anything, but I do have some piston slap that quiets down after warming up.

Should I grab the oil sample on my next oil change? I typically change oil at 4500-5000 miles. Is that too late in the cycle? Or should I take a sample sooner? Also, are there any labs you could recommend? Thanks.

 

[Mooseman]

It`s usually done at the oil change. I would think that they take the number of miles on it when giving the results.

 

[BrianF]

No harm in taking a sample when you change it. Otherwise you need to figure out a way to take another representative sample midway. You don't want to waste any oil, have to add any or introduce any garbage into the system.

If your drive cycles are comparable, take the sample when you change the oil and adjust your mileage next oil change index accordingly.

As for company, there quite a few inches the US to try. I suggest not doing Blackstone as their fuel dilution test is just that open pan flash point or whatever it's called. Its not accurate. Find one that test with mass spectrometry. Lots of heavy equipment dealers such as zjohn Deere, Cat, etc will have test kits.

With your relative short change indexes, likely does not care much about TBN/TAN but it can help with extending your changes.

In Canada, I use Fluidlife. They work great.

 

[Mooseman]

Speediagnostix is associated with the Motor Oil Geek and he knows oil. I haven't used his UOA service but I'd certainly use it if it weren't for shipping from CAN to US.

I should look into getting UOA done.