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

[Silver]

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.

 

[WylieCoyote]

Not necessarily. My 2002 Altima 3.5 turned Mobil 1 dark very quickly, and the engine was brand new......there was nothing to clean. At least part of the darkening is a result of temperature reaction combined with combustion by-products.

 

[SZR48207]

Which is why there are time-based oil change intervals ( 5k, 10k, etc) and OLMs.

 

[Jetronic]

The inverse is likely true... if the oil stays visually as clean as it went in, regardless of how long it's in there, it's proably not keeping stuff in suspension

 

[BlueOvalFitter]

About every diesel engine I have changed the oil in, the oil turned black after a few hours, or less, of running.

 

[The Critic]

I have found most oils to turn darker with use....no surprise.

I have also found some brands of oil to turn reddish/dark early on. Amsoil SS seems to be one of them.

 

[Jetronic]

About every diesel engine I have changed the oil in, the oil turned black after a few hours, or less, of running.

I have seen diesels that don't turn the oil black, but those were the exception and I'm sure we had more diesel engines here in europe to find such unicorns

 

[Silver]

I have found most oils to turn darker with use....no surprise.

I have also found some brands of oil to turn reddish/dark early on. Amsoil SS seems to be one of them.

Our Pentastar turns Castrol Edge dark pretty quick with a reddish color.

 

[The Critic]

Our Pentastar turns Castrol Edge dark pretty quick with a reddish color.

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.

 

[Passport1]

The color of oil only concerns me when I'm fryin' chicken.

 

[madeej11]

I have found most oils to turn darker with use....no surprise.

I have also found some brands of oil to turn reddish/dark early on. Amsoil SS seems to be one of them.

I use Amsoil SS and it is a medium honey color and when mileage accumulates it just gets a darker version of that same color. It takes quite some time for it to get dark but it doesn't get red.

 

[Driz]

About every diesel engine I have changed the oil in, the oil turned black after a few hours, or less, of running.

Yup and it still gives me the creeps. The difference between 5-10 hours of gentle use and beat to crap is visually indistinguishable.

 

[samven]

This seemed to be a bigger issue before synthetic. I remember it seemed that QS would go black by the time I had 1500 miles on it but Pennzoil seemed to stay mostly clean looking through the whole 3000 oci. Since going synthetic or at least since the SM and SN ratings I am still having a hard time seeing the oil on the dipstick after 5000 miles.

 

[WylieCoyote]

The propane-powered forklift I used & maintained at one of my past jobs never darkened or even colored the oil. You couldn't tell the difference between new oil and used oil at the oci. I know it got hot because we used it for hours on end moving pipe back and forth across the yard in the summer. That tells me that combustion deposits play a substantial role. I pay no attention to the color, just the time and the mileage.

 

[y_p_w]

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.

Really? I always thought that GTX was on the same level/price as standard Pennzoil (yellow bottle), Valvoline (white bottle), etc. Some (but not all) of the major oil companies like Mobil, Chevron, or Shell (at least the American version) were sold at a lower price.

Back then I remember the next step would have been synthetic like Mobil 1 or Syntec. I also don't remember too many shops that would stock any.

Isn't Liqui Moly is super expensive.

 

[The Critic]

Really? I always thought that GTX was on the same level/price as standard Pennzoil (yellow bottle), Valvoline (white bottle), etc. Some (but not all) of the major oil companies like Mobil, Chevron, or Shell (at least the American version) were sold at a lower price.

Back then I remember the next step would have been synthetic like Mobil 1 or Syntec. I also don't remember too many shops that would stock any.

Isn't Liqui Moly is super expensive.

GTX was marketed as a premium product - or was perceived to be a premium product and was carried by the better independent shops. At least that was my recollection. Not sure if the product was anything special, but it certainly carried a lot of advertisement.

Liqui Moly isn't priced particularly high when purchased from wholesalers or the various online sites. On average, 15-20% higher than Mobil 1 but many Euro mechanics speak of it as some unicorn juice. Not sure what the big deal is, as the UOA's do not show anything spectacular.

 

[ruSSrt]

I got two diesels in my garage. Both use same oil Rotella t6.
01 cummins 5.9 only starts to change color after about 1500-2000 miles (112xxx on the engine)
05 VW TDi ( EGR deleted) with 200xxx miles turn oil black after 250 miles. Is it just because it's older motor? More wear on it? Who knows.

 

[y_p_w]

GTX was marketed as a premium product - or was perceived to be a premium product and was carried by the better independent shops. At least that was my recollection. Not sure if the product was anything special, but it certainly carried a lot of advertisement.

Liqui Moly isn't priced particularly high when purchased from wholesalers or the various online sites. On average, 15-20% higher than Mobil 1 but many Euro mechanics speak of it as some unicorn juice. Not sure what the big deal is, as the UOA's do not show anything spectacular.

GTX was just Castrol's American division's entry level motor oil. I do remember them marketing it as having "maximum protection against thermal breakdown" but I took that as more or less marketing speak.

 

[UG_Passat]

my old TDI... Mobil Delvac 1 5w40 is a nice clear golden color out of the bottle... and as soon is the engine was started, and after a few minutes... nice and black

 

[ZZman]

Of course I believe that. And no one will change my mind!