General Category >> Technical Documents/Reference >> Oil analysis on the cheap

Message started by verslagen1 on 07/18/10 at 19:39:18

Title: Oil analysis on the cheap
Post by verslagen1 on 07/18/10 at 19:39:18

The blotter spot test:

Using just this simple layman's oil analysis test can shed light on a wide range of potential oil problems which could require an oil change: excessive particulates, condensation build-up, glycol contamination, fuel dilution, failure of dispersant additives, formation of sludge and oxidation products. It is probably one of the most useful DIY oil analysis tests you can perform, and it's drop dead simple.

While your engine (and the oil) is WARM (not HOT), allow a drop of oil to fall from your dipstick onto a heavy, white, NON-glossy business card. Lay the paper or business card flat, but so that all but the very edges of the paper is suspended. As a possible example, if you're using stiff card stock or a stiff business card (which you really should be) simply set the card across the top of a cup or mug of some sort.

You want to wait for the paper or card to absorb the oil drop completely which might take awhile. The list of characteristics below should help you evaluate the condition of your oil based on the DRY oil spot.

If your oil is still good for continued use, the dry oil spot will be uniform in color without any especially dark areas or rings. There may be a slightly yellow outer ring.
If your dispersant additives are failing, you'll likely see a very dense and quite dark area, normally within the center of the circle. Consider changing your oil soon, especially if any other issues come up in the course of "testing".
Glycol (antifreeze) in your oil? Expect to see a very black and somewhat "pasty" zone within the oil spot. Change your oil very soon.
If the circle is really dark throughout and has a very distinct outer ring, your oil is severely oxidized and needs to be changed immediately.
If the center of the circle is quite dark and there are outer rings you may likely have fuel in your oil. This does not necessarily mean that you need to change your oil since it is common to have fuel in your oil, but it could if the level is too high. Only a professional analysis will tell you how high those levels are.

Michael Kaufman -

Title: Re: Oil analysis on the cheap
Post by verslagen1 on 07/18/10 at 19:39:32

The crackle test:

Even though any individual can end up with water in their engine oil, it is more commonly an issue for those vehicle owners that make primarily low mileage trips with their vehicle, drive their vehicle very infrequently and/or live in a humid climate or one with significant fluctuations in temperature. If you happen to be one of these individuals, I would highly recommend that you perform the crackle test, which is useful for determining whether condensation has caused a build-up of water in your oil.

So, how do you do it?

Simple. Find a hotplate of some kind. Set the temperature between 250 and 300 degrees F (which is greater than the boiling point of water - 212 - but lower than the typical volatility level of a motor oil - which is generally greater than 350). Then, place a few drops of oil on the plate.

When you place the oil on the plate, you will hear a crackle as the water boils off. The crackling should occur very quickly as long as the amount of oil you use is small. Of course, if there is no water in your engine oil, you will hear no crackle.

Michael Kaufman - » Powered by YaBB 2.2!
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