Oil Analysis value

[Gros Ventre]

There has been much discussion on whether doing oil analysis is worth it if you change your oil anyway every 3-4,000 miles. Here's an example of why it makes a difference. I use sample results to tell me when to change oil. In my most recent sample I had the following values that stood out to me and tell me I have a leaking fuel injector.
My assessment is that there is a leaking fuel injector. I base this on these readings:
Fuel % is as high as it's ever been.
Both viscosities are as low as they've ever been.
Flash point is as low as it's ever been.
Ash content has nearly doubled.
Zn is up quite a bit.
Boron is as low as its been for a sample taken 4-5,000 after an oil change.

The key here is had I been just changing the oil without sampling, I'd have never discovered this.

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[fordtruckman2003]

With a Powerboost how are you getting engine running hot to burn off startup fuel dilution?

My understanding is that it will cut on and off all the time. In a traditional configuration a 30 minute drive gives a clean sample. Powerboost could start and stop multiple times in the same drive.

 

[SALEEN961]

Just out of curiosity, how high is the fuel percentage in your last sample and do you notice a strong fuel odor? Fuel dilution is extremely common on GDI engines and I frequently recommend early oil changes or diag based on the oil having a strong fuel odor.

At some point I would like to send in an oil sample with a faint fuel odor and one with a strong fuel odor to get a better idea of how much fuel is really there when I can smell it.

 

[Gros Ventre]

Just out of curiosity, how high is the fuel percentage in your last sample and do you notice a strong fuel odor? Fuel dilution is extremely common on GDI engines and I frequently recommend early oil changes or diag based on the oil having a strong fuel odor.

At some point I would like to send in an oil sample with a faint fuel odor and one with a strong fuel odor to get a better idea of how much fuel is really there when I can smell it.

1.5%... No particular odor,

 

[imnuts]

I wouldn't consider that dilution as a leaking injector. If you didn't have a long drive beforehand or had a few quick engine cycles before pulling the sample, it's likely normal. I had dilution close to that on my first sample. Paid more attention to my driving before getting the second and avoided having the engine kick back on as I was parking and had no dilution on that sample.

 

[Gros Ventre]

K, lemme think on it... 'preciate it.

 

[KTM753]

Here is a great video on this topic and engines. Lake Speed Jr. offers great insights into oil and engines. This will back up Mr. Grow Vonts points in this thread but also shoots holes in the manufacturers recommend intervals and cluster oil life meter...

 

[Calson]

A lot of assumptions being made that are not backed up by research by auto engineers. There is a reason why fleet operators with thousands of vehicles will do oil analysis for diesel engines that go 25,000 miles or more between oil changes and do not do so for their vehicles with gas engines.

 

[Gros Ventre]

Nearly all gas engine folks are only interested in getting to their next trade in... So why do it...? In my case I make mine last many, many more years than that... As in 30 years for my 92 Suburban... So there is plenty of reason for gas engine guys to do it, if they think like that.

 

[Severdog]

Nearly all gas engine folks are only interested in getting to their next trade in... So why do it...? In my case I make mine last many, many more years than that... As in 30 years for my 92 Suburban... So there is plenty of reason for gas engine guys to do it, if they think like that.

Did you ever get to the bottom of your dilution issue? I have similar dilution issues showing up on oil analysis.

 

[Gros Ventre]

I believe it was a result of taking the sample too soon after starting the engine. A followup sample was OK.

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