Do you think black oil is really a sign of cleaning?

[ssspencerjr]

I bought my 04 silverado back on May with 118k on the odometer. First thing I did was change the oil, out came black oil. Put in valvoline advanced syn, all I had at the time. 900 miles later it was black. Drained it again and in went mobil 1. 900ish miles later and it's just about as clean as what went in. Only thing I can think of is that it cleaned out gunk. I never cut open the filters though.

 

[Gimpy1]

It'simportant to note several things. What type of fuel is beig used gasolie, diesel, propane or alcohol. Each fuel will make oil darker or not at all. Secondly what type of engine is it? Port or direct injection. IMHO judging the cleaning factor of oil by how fast it gets black is a very poor litmus test.

 

[ssspencerjr]

It'simportant to note several things. What type of fuel is beig used gasolie, diesel, propane or alcohol. Each fuel will make oil darker or not at all. Secondly what type of engine is it? Port or direct injection. IMHO judging the cleaning factor of oil by how fast it gets black is a very poor litmus test.

My example was the 4.8 gas engine, 87 octane, port injected.

 

[doublebase]

What I’ve discovered over the years is engine age (mileage) makes a difference in oil color...the more miles it has, usually up over 150,000 miles, the oil seems to get darker, quicker throughout that oil change interval. That’s just what I’ve personally noticed throughout vehicle ownership. I assume that’s because as things start wearing with mileage (rings) combustion gases get into the crankcase easier/quicker/more often and change the color of the oil. And plus, with all those miles on that engine, things are starting to build up inside...varnish, soot, etc...and your oil is coming in constant contact with that, cleaning it sometimes and carrying it in the oil.

Ive also noticed the oil in my direct injection engines get darker quicker, compared to my port injection engines.

This is what I’ve noticed^^^

 

[Silver]

I bought my 04 silverado back on May with 118k on the odometer. First thing I did was change the oil, out came black oil. Put in valvoline advanced syn, all I had at the time. 900 miles later it was black. Drained it again and in went mobil 1. 900ish miles later and it's just about as clean as what went in. Only thing I can think of is that it cleaned out gunk. I never cut open the filters though.

I've seen myself, and many mentions of Mobil 1 coming out 'clean'. I wonder if you went back to Valvoline after the M1 if it would come out clean?

 

[Graham Piccinini]

A tank of gas lasts me 275 miles. Nearly every tank of gas my oil level is 1qt low. I top it off and usually by 3rd tank of gas the oil is jet black.
2000 Honda CR-V, 220k+ miles, AWD and very short geared 5-speed. 60mph=3k rpm, 80mph=4k rpm. I'm basically required to stay between 3k-5k rpm, just to keep up with traffic... Hoping for the piston soak to reduce oil consumption (assuming carboned up ring lands), but also searching for a low mileage engine...just in case it is too worn out.

 

[Silver]

A tank of gas lasts me 275 miles. Nearly every tank of gas my oil level is 1qt low. I top it off and usually by 3rd tank of gas the oil is jet black.
2000 Honda CR-V, 220k+ miles, AWD and very short geared 5-speed. 60mph=3k rpm, 80mph=4k rpm. I'm basically required to stay between 3k-5k rpm, just to keep up with traffic... Hoping for the piston soak to reduce oil consumption (assuming carboned up ring lands), but also searching for a low mileage engine...just in case it is too worn out.

Wow.

 

[wdn]

You should he looking at the cause and cure for that massive oil consumption and not relying on magic properties of motor oil or to be replacing the engine.

 

[MolaKule]

In regards to the cleaning agents people use.

If the oil comes out black, we're like oooooo aaaaahhh... it's working!

But as far as we know the chemical itself could just be turning black, I mean varnish isn't black, it's more of a gold color.

Or is that pretty stupid?

Honestly asking.

1. No cleaning agent will turn black after installation into the crankcase.

2. If the oil is clean at the start and then If you add a cleaning agent such as a Flush chemical (a solvent), and the oil turns black, then you have caused the more agglomerated hydrocarbons to have become suspended in the oil.

Of course, after any cleaning, the filter and oil should be changed to an oil speced for your engine.

 

[Blinker]

A tank of gas lasts me 275 miles. Nearly every tank of gas my oil level is 1qt low. I top it off and usually by 3rd tank of gas the oil is jet black.
2000 Honda CR-V, 220k+ miles, AWD and very short geared 5-speed. 60mph=3k rpm, 80mph=4k rpm. I'm basically required to stay between 3k-5k rpm, just to keep up with traffic... Hoping for the piston soak to reduce oil consumption (assuming carboned up ring lands), but also searching for a low mileage engine...just in case it is too worn out.

Sounds like that engine is in need of a rebuild.

 

[vvti16valve]

simple to answer this question..
just add a liitle bit of new oil into a container
and then heat the bottom of the container with fire until hot
and see and look at the color of the oil will change
oil turning black doesn't mean anything
add a little ester and see the color after a while

UOA the best answer to see the ability of the oil

 

[hrv]

Years ago when I used ARCO Graphite.... it was black going in new....

 

[GMBoy]

Off-topic: Growing up in the 90's, Castrol GTX was marketed as the "premium option" at high-end import garages, similar to how Liqui Moly is marketed today.

Nowadays, I rarely see Castrol used around here...except when they supply the OEM brand service fill.

I agree and remember well when I was young my father used Castrol GTX but then stopped using it when it no longer had a diesel rating with the car rating. My dad felt the oil was not longer as good since it didn't carry both gas and diesel certifications. Today I still don't use Castrol products unless its a BMW or similar that calls for it.

 

[GMBoy]

I remember my dad having an 84 Cadillac Seville Diesel - the oil would be black the instant it was started after an oil change!

 

[OilUzer]

That's why I change the oil when or before it gets too dark!

Experts say color does NOT matter but if unwanted stuff are "suspended" in the oil and causing it to go dark or black ... how do I know if the oil has not reached its limits and deposits begin?
Pay more $ for another useless (some may argue) analysis or change the oil?
Easier to get some fresh oil in and reset the "suspension" cycle.

p.s.
I don't own a diesel and my oils last at least 3-4K miles before starting to get a little dark. Except one DI engine but that one gets a short oci regardless.

 

[Slow Car Sport Mode]

I remember my dad having an 84 Cadillac Seville Diesel - the oil would be black the instant it was started after an oil change!

Well, yeah!

 

[demarpaint]

Black oil could also be a sign of a dirty running engine, diesel engines come to mind. I'm sure there are a lot of gas engines running poorly, which might be the reason of people stating the oil gets dirty fast. I'd be willing to bet a healthy well maintained engine with no mechanical issues is going to have the oil stay cleaner longer, and there are some engines that due to design [possibly poor design] run more dirty than others. Some early DI engines come to mind.

Bottom line, knowing the engine in question, the condition, and how it was maintained would be helpful.

 

[53' Stude]

Black, dirty engine oil in gas engine means the oil is doing its job.

 

[RDY4WAR]

A lot of these quick flushes contain solvents like isopropyl alcohol which are also weak acids and can cause oil oxidation in much the same way as fuel dilution. The oil coming out black, it could be from carbonous deposits getting kicked into suspension or it could just be the flush itself turning the oil black from oxidation.

Some ashless dispersants can darken from UV exposure (from combustion events) making the oil appear black when it actually isn't. This is rare though.

There's also some oils that are pretty dark in virgin form from high amounts of sulfur.

I view oil color as just one more observation for trends. If I notice the oil gets pretty dark around the same time the UOA shows it's time to change it, then I can follow that. If the oil suddenly starts getting dark sooner, I know something isn't right.

 

[dbias]

Black oil is a sign the oil is holding soot in suspension, especially in a diesel engine.