DIY Oil Condition Tester
 

I have a few cars and as such they mostly do low annual milages. Mail away testing always seemed like a pain, but I chanced across this:

Buy Digital Motor & Engine Oil Tester Online ? Lubricheck

Reviews on Amazon:

Robot Check

Thoughts?

EDIT: After going through the Amazon reviews I decided to give it a go for myself, we'll see in a weeks time.

The folks on the Cummins forum had an informative discussion of this device.

Lubricheck - Page 3 - Dodge Cummins Diesel Forum

Nothing conclusive, but interesting. They also refer to another thread or article that was critical of the technology used to determine oil fitness.

And here's one on GM's oil sensor, from Delphi Mexico. You can preview the first few pages for free, where they explain what the sensor's doing. No reason this thing can't do the same.
“Smart sensing” of Oil Degradation and Oil Level Measurements in Gasoline Engines

Frank

Does it test acidity or electrical resistance? Better than nothing i suppose but definitely not conclusive.

I would guess conductivity. They said it gives false positives on oils with too much zinc or other high pressure wear additives.

If anybody knows how they work exactly that would be worthwhile. I'm thinking my Fluke multimeter could do the same test.

Guess I better go look at that GM paper.

Yup, the GM sensor works with conductivity and indirectly measures pH. And they claim you have to measure the conductivity with AC, not DC.

Sounds crazy, but i just change the oil every 5k miles... personally. Smell test is a good indicator of fuel dilution and if you have an air/oil separator you will know how much moisture you have coming out of the oil.

There is no good remote instrument that actively measures pH.
Conductivity is typically measured with AC. Any current induced onto the wires will throw the reading way off. I think hand held conductivity meters use DC.

My problem is the cars in question do 2k or less a year. In the case of my Fiat's fancy required oil it's also around $100 a bottle of oil and filter.

Any idea if a pool tester kit would suffice? What would be the healthy PH range of motor oil?

Biodiesel guys like test strips, but motor oil would turn the paper black.
A hand held pH meter that can do oily samples should work, just have to reset it to a known sample before every use.

Since all the additives I know about in oil appear to be alkaline and since we know acids are highly undesirable in the engine then I would think any reading less than 7 would mean its time for an oil change.

What insane specification does the fiat oil need to meet to make it so expensive?

On our VW it calls for some euro spec oil. I looked up the additive package on these oils and found out that the new generation of oils called for in the emissions controlled diesel trucks for the US market have additive packages very close to what VW calls for.
Turns out the VW oil spec for the late 90s and early 2000s is pretty close to what 2007.5 and newer diesel trucks call for.
The diesel truck oil is only $5 to $10 cheaper per oil change than the euro spec oil, not a huge deal but the real problem was no one had any around these parts. I can get this diesel truck oil from any local store. I had only been able to find the euro spec oil at stores in and around major cities no where near where I live.

Fair point about the oil usually being too dark for the test strips to work, but my oils are changed while still looking virtually new, so it's probably worth a try.

The Fiat requires Fiat approved oil, the specs probably not that different to other OEM specs, but all similar oils are fairly expensive. There's plenty of controversy surrounding Fiat Twinair oil specs online, some have filled with non-approved specs and reported trouble (which was surmised to have come from the oil actuated intake valves), but I just check the specs on the US Multiair engines and plain old mineral oils are acceptable for them. I ran a Shell 'performance' oil as opposed to the required 'economy' spec at my last change with no issues, I reasoned if it was good enough for a 911 Turbo it should be OK for my Fiat, still cost me around US$70 though (an oil and filter in my TDi cost closer to US$140! - nearly two gallons of DPF spec oil). At the upcoming change I plan to go back to the Fiat spec if I can get a hold of the stuff at all.

"Ash" is a byproduct of the oils detergent dispersant being burned.
It clogs up catalytic converters.

I run high ash oils.

The SAE papers that I read about the original GM Oil Life Monitor (OLM) system stated that it only used TIME and TEMPERATURES, there were NO special sensors (viscosity, ph, etc.) involved.

How the OLM works.
GM engineer, Ms. Ellen Shirley Schwartz, PhD, is one of the researchers who developed the GM patent (#6,327,900 B1, dated 11-Dec-2001):

http://www.google.com/patents?id=jpo...page&q&f=false

...the flow chart in Fig. 2 explains which parameters the OLM monitors and measures. Basically, there are three controlling parameters: the engine revolutions, the oil temperature, and the oil contamination:

• the oil "temperature (T) equation" used in the program is:

T(o) = k(2) + k(3)*S(e) + k(4)*T(c) + k(5)*F(q) - k(6)*T(a) ± k(7)*V(s)

...where:

S(e) = engine rotational speed, rpm
T(c) = coolant temperature, ºC
F(q) = fuel quantity, cubic-millimeters-per-cylinder
T(a) = air intake temperature, ºC
V(s) = vehicle speed, mph
k(2) = constant (-9.0 *)
k(3) = constant (0.012 *)
k(4) = constant (0.95 *)
k(5) = constant (0.21 *)
k(6) = constant (0.001 *)
k(7) = constant (0.01 *)

• the oil "contamination (C) equation" used in the program is:

C = k(8) + k(9)*I(t) + k(10)*F(q) + k(11)*T(o) + k(12)*S(e)

...where:

I(t) = fuel injection timing, degrees crank angle
F(q) = fuel injection quantity, cubic-millimeters-per-cylinder
T(o) = calculated oil temperature, ºC
S(e) = engine rotational speed, rpm
k(8) = constant (-2.7 *)
k(9) = constant (0.2 *)
k(10) = constant (0.03 *)
k(11) = constant (0.02 *)
k(12) = constant (0.001 *)

* = derived values for GM 6.6L V8 diesel test engine.

Thus, contrary to what Mr. Bob-the-Oil-Guy said, GM is actually tracking "calculated" oil contamination--not its ZDDP content--with the OLM...at least, as stated in their 2001 US Patent.

I have a 'distance to oil change' read out on my Renault.

It's a petrol manual so I EOC a lot. When I first bought it, the change oil warning came on at around 3000km from new. I re-set it and it didn't come on again (oil changed at 15,000km) - I don't remember what it read prior to reset. There is no requirement for a low mileage break in oil change.

Now on my second oil fill, the distance to oil change with roughly 1000km down is reading 7000km to go (but it's falling far more rapidly than the distance I drive), so it seems set to come on at around 4000km.

15,000km is the factory oil change interval.

So it seems EOC is tricking the program, but oddly, it seems only on fresh oil.

So I got my tester.

From the instructions:

I went and tested the oil in my Fiat first, it's 12 months old but only covered 2,000miles, most people (and the service manual) will tell you to change at 12 months regardless of mileage.

It takes around 10 drops of oil to fill the sensor dish, so it's unfortunately a case of dipping the dipstick multiple times which can make a bit of a mess.

This oil scored '1' (out of ten)- new oil. So there's the Lubricheck paid for immediately.

I cleaned the sensor to try another vehicle, but you not only have to get the sensor truly clean, you'll have to wait for all traces of solvents to disappear. I used kerosene to clean the sensor followed by dry paper towels, but it still wouldn't initialise. After leaving it to dry for the day it worked again.

My Lubricheck unfortunately arrived just after I replaced all the fluids in the Jeep, they would have been interesting to test. I'll try the Prius next as thats the next oldest oil I have.

The Prius' 5 month oil (~3000miles) tested a '5' so getting close-ish to a change, I'll re-test in 2-3 months. This car does all of our short trips so oil degrading shouldn't be a surprise.

Next I checked my daily driver Renault, about 4000 miles and 5 months on it's oil and it came back a '1'. This was a bit of a surprise since the engine operates in 100% city traffic with lots of EOC (but it does a minimum of 10 miles each way daily so it gets up to temp properly), it's a bit irrelevant as I have to change the oil every 12 months in order to maintain the warranty. It does confirm that my EOC is confusing the on board 'miles to oil change' display and that there's nothing actually wrong with the oil.

Also the problem with getting the sensor clean has gone away, I was able to get the sensor clean with nothing more than some tissues, didn't need the Kerosene at all today.

So over all, I'm very happy with this unit and would definitely recommend. It's cheaper in the long run and much more convenient than lab testing (you could quite easily monitor your oil on a monthly or even weekly basis - which you can't really do with lab tests). It won't give you those fancy report with percentages etc but I don't feel the majority of people really need that kind of detailed info.

It's certainly better than guessing.

Already I've learned that it seems changing oil at 12months is a myth. It seems that because all my trips in the Fiat are 50miles+, the low annual mileage doesn't mean the oil is in need of replacement. I might leave the oil for another year and send it off to a lab for verification then.

Re-Tested the Prius oil and scored '6'. Looks like it loses one point per month, so the oil is good for 9 month intervals - will be interesting to see what happens when I switch to fully synthetic - I have a fair bit of mineral oil to use first though.

Screw it I am getting one too.

We talk a lot about saving fuel but not really about saving lube.

Be sure to wipe off the dip stick the first time. I find they some times slightly magnetize and attract more iron that gets into the oil.

It's already saved me about $150 so not a bad ROI, especially those of us with multiple cars, cars with big sumps and cars that need expensive oils.

I think this device would be suitable for testing drive train fluids too. I'm going to change gearbox UFI's oil at around 18,000km, so I'll test that as well, actually my yet to be delivered Renault will probably reach that mileage first.

I got mine in.
Back at the beginning of February I changed the oil in my wife's Hyundai and our VW at the same time put the same oil in both.
Last weekend her car showed an 8 out of 10. So I changed the oil.
The peoplescar was a 3 and I did not change the oil.
The difference between them was her car has 2 more trips to Dallas on it and it does all of our running around in town.
I only drive the VW only to and from work since running over a stick could cost me another $1000.
I only drive the VW to dallas if i have to.

We are driving both cars to Dallas again and I plan on retesting both again. A trip to Dallas for us 430 miles each way.

I have a 2001 Silverado with 6.0 gasser. It tells me to change the oil at 6000 miles more or less.

So my Prius oil finally 'failed' the test - scored a 10 after 12 months and 3,000 miles. It seems the oil tester isn't really linear, the oil sat on 7-8 for a long time, but then basically skipped the 9 and straight to 10. It was dealer oil so I don't know what was in it. Refilled with semi-synth 5W-40 as that's what I had and have no other use for.

The car's being sold so I won't be able to report any more long term monitoring. All other cars including the F1 still scored 1 or 2.

sounds good.