Oil Test Question

[slomove]

After the PNW 2005 trip I changed oil and sent in a sample to Blackstone Labs (see below, you need to click on it twice to see full text resolution). While I am happy to see confirmed no coolant or water in the oil I am worried about the high silicone (i.e. dirt) and iron (i.e. abraded material) after only 5000 miles. That leaves me doubting the efficiency of my ITG foam air cleaners. Thinking about it I always have a thin layer of dust sticking to the inside of the TB trumpets. How often should the filter foam be washed and re-oiled? I have done this once per year because it is a pretty messy job.

 

Another question, has somebody seen similar oil test results? I am not sure what to think about the dilution with fuel.

 

Thanks,

 

Gert

 

P.S.: The very high anti-wear additive numbers come from the racing oil I used.

 

 

http://www.usa7s.com/aspnetforum/upload/1896182450_BlackstoneReport.jpg

[scannon]

Gert,

 

I'm not familiar with your specific brand of air filters but the K&N company recommends 50k mile cleaning intervals on their foam filters. Their literature suggests that a slightly dirty filter cleans better than a freshly cleaned one.

 

If I could find a quality paper filter in the same configuration as the K&N on my Se7en and Miata, I would go with that and change it when it started looking dirty.

 

I would guess that the excess fuel in the oil is from running a bit rich combined with lots of high rev open throttle (i.e. FUN) driving. Another source of it could be rings that are not sealing as well as they should.

 

Even with all that has been said about extended oil changes and synthetic oils, I still change oil on my turbo cars at 2 - 3k miles and non-turbo cars at 3 - 4k mile intervals. I also change the oil after every track day whether it has the miles on it or not. Cheap insurance for the engine.

 

Skip

[slomove]

Thanks Skip!

 

In the meantime I forwarded the result to the guy at CenPeCo who formulated the oil that I use. He told me in their experience the measured iron content is quite normal for a gasoline engine and the silicone content is not likely from sucked-in sand dust because then the aluminum values (from clay dust) should typically also be high. It is probably wash-out from a new silicone rubber valve cover gasket that I installed a few months ago. So, for that matter my air filter is probably not an issue.

 

The gas in the oil is probably caused by my stuck thermostat and the oil-coolant heat exchanger that does not allow fuel in the oil to evaporate properly. Got to fix that ASAP.

 

Anyway, interesting to see what you can read from such an oil test. For $23 it is quite affordable.

 

Gert

[Al N.]

Gert-

 

Interesting. Can you post up the info for the oil lab?

 

I re-oiled my ITG once (after my epic rain drive to Skyline East in 2006)...it wasn't so bad!

 

-Al

[slomove]

Al, the company is Blackstone Labs. But there are others, too that may even be cheaper.

 

Blackstone ships a free sample kit that can be sent back in regular mail; it was quite easy. The evaluation took some 3 weeks to be processed.

 

If you are ever in doubt about the head gasket or many other engine functions this is a cheap insurance.

 

Gert

 

P.S.: Last time I oiled the filter foam I think I overdid it.... the first starting attempt ended up in a very loud bang from the air filter and a big plume of stinking smoke. I guess some of the excess oil was atomized and got somehow ignited by backfire.