engine oil analysis for the poor

[upontheriversky]

Blotter Spot Test

Objective: oxidation products, sludge formation, dispersancy failure, glycol contamination, water contamination, fuel dilution, and high levels of particles.

1. place a drop or 2 of used oil on a good heavy white card (i.e. business card)
2. suspend the card, use 2 pencils on a table and place it so both ends of card resting on the pencils
3. wait couple of minutes until the oil drop is fully absorbed by the card
4. start evaluation:

- A colorless spot or slight yellow outer ring - "good" oil.
- A dense, dark deposit zone – Dispersancy failure
- A black, pasty zone – Glycol (Antifreeze) in your oil
- A dark center with distinct outer ring – Severely oxidized oil
- A dark center with surrounding rings – Fuel in oil

Crackle Test

Objective: to test for water ingression into oil from condensation. normally happens on cars with frequent short trips or on cars not being run for long period

1. fuel in oil can temper with test result, so do blotter spot test first to make sure.
2. drop a small quantity of used oil on heated frying pan which is already hot enough to boil off any water
3. if there is water present in oil, you should hear crackle noise from water being boiled off
4. if no crackle, means no significant amount of water present

Used Filter Inspection

Objective: to check for significant engine wear and tear

1. Cut open the filter
2. if large amount of metal shavings present, with some of it being fairly large. serious wear issues may have occured.
3. check for "blobs" or "gummy" oil on the filter media for presence of sludge

Oil On Water

Objective: to check for contamination or oxidation

1. new oil will bead up when dropped on water surface
2. if the oil drop spreads out, it means ur oil is either contaminated or already oxidized


The Rub Test

Objective: to check for oil contamination

1. do this test shortly after driving, make sure oil is not too hot that it will burn your hands
2. take a drop of oil on dipstick and rub it between fingers.
3. if it feels fairly "grainy" like there are tiny fibres present, change the oil as it is pretty contaminated already


The Smell Test

Objective: to check for oil oxidation

1. take a new bottle of engine oil u have used on last oil change and smell it. this is the smell of a new and in good condition engine oil
2. take a drop of ur used oil and smell it, if it smells more like "burnt" compared to the new oil, it means oxidation has occured
3. but take note, some oxidation is normal, it is just an indication that ur used oil is not as good as new.


All the above tests are not as precise and accurate as a proper UOA but it will give u a cheap, fast and reliable way of knowing the general state of ur engine oil. it is also good for rough comparison between different engine oils you are using

So you know whether the oil can still be used or it will need to be changed immediately

reference: themotoroilevaluator.com