Mobil 1 EP black in 800 miles....

[KCJeep]

So my son bought a Mazda 6 late last year with 113k on it. Has been a great car so far. The oil was dark when we bought it and the PO said it needed a change, but looking through the fill hole all looked pretty good. Upon purchase we put SuperTech full syn 5w30 in it which we ran up to 120k. It was pretty dark by that time. My son doesn't care to change oil so I talked him into 10k OCI's, which he started at the 120k change.

I suggested a number of longer OCI oils, and HE picked Mobil 1 5w30 EP as it was on my suggestion list for 10k oils. We just checked it at about 800 miles now, and the stuff is black already. Pretty surprised, it was also down about a half quart but I warned him about that and Mobil so he will check again in 500 miles or so. I'm betting the consumption will have slowed by then and will likely taper off I'm guessing. But black in 800 miles? I was pretty surprised for a "clean through the fill hole" vehicle, it must be doing quite a bit of cleaning. That's all I can attribute it to anyway...

We will run this stuff the full 10k no matter what it looks like by the way. As far as we know the car had not had synthetic in it until we put in the ST full syn last time around. The history appeared to be dealer and quick lube places in the past from what records there were.

 

[901Memphis]

That is probably the oil holding in contamination that was previously un released by lesser oils.

 

[Linctex]

Originally Posted By: 901Memphis
That is probably the oil holding in contamination that was previously un released by lesser oils.


X 2

It is rather unlikely (unless the engine is severely out of tune) that normal operation is fouling the oil.

It's probably just cleaning & holding the gunk.

 

[blupupher]

Oil color is not indicative of oil life. Is it "cleaning up" the dirty engine, probably.
Sounds like you know this since you plan on having him run it 10,000 miles regardless.
What filter did you put on it?

 

[TmanP]

Mobil 1 high mileage (their "cleaning" oil) recommends a few earlier changes to remove any deposits:

"If your engine contains excessive sludge deposits due to less-than-adequate maintenance practices, Mobil 1 High Mileage synthetic motor oil can help reduce this sludge. For severe cases of engine sludge, short oil change intervals (3,000-5,000 miles) are recommended for the first two or three oil changes as the sludge reduction takes place. (In cases of engine damage that may have resulted from poor maintenance, even Mobil 1™ motor oil cannot remedy years of neglect.)"

I'd follow this advice and maybe do a few early changes, especially if it's that dark that soon.

 

[Kuato]

Cleaning is occurring....still probably good for 10k miles if there is concern, UOA at 5-6k....

 

[BobsArmory]

Originally Posted By: TmanP
Mobil 1 high mileage (their "cleaning" oil) recommends a few earlier changes to remove any deposits:

"If your engine contains excessive sludge deposits due to less-than-adequate maintenance practices, Mobil 1 High Mileage synthetic motor oil can help reduce this sludge. For severe cases of engine sludge, short oil change intervals (3,000-5,000 miles) are recommended for the first two or three oil changes as the sludge reduction takes place. (In cases of engine damage that may have resulted from poor maintenance, even Mobil 1™ motor oil cannot remedy years of neglect.)"

I'd follow this advice and maybe do a few early changes, especially if it's that dark that soon.


Yep

 

[bbhero]

+2

I agree with BobsArmory and TmanP. That sounds like a good plan of action straight from Mobil 1 themselves.

 

[toneydoc]

And do remember that not all oil comes out while draining. Probably 10% or so remains in engine and its recesses.
So that gets mixed up and in and the oil looks black. Does not mean it is bad or got used up or cleaned that fast.
Still great oil with some colorant from previous oil mixed in. Great choice of oil BTW

 

[KCJeep]

We put one of my favorite filters on it, a Motorcraft FL-400s. I will keep an eye on it but a change of filter at 5k might be warranted by the looks of things. There is no way he is going to do a UOA, which is why the EP was one of my recommendations for a 10k run.

I am surprised at how much "cleaning" it is apparently doing in an engine that was not particularly dirty as far as we know. And I am not a Mobil guy by any means but I admit I am impressed. The engine runs like a top, there is no external indication of contamination so I really think it is just getting crud loose. I am certain it is not a "sludger" though, so early OCI's are not warranted IMO.

Like all our 5w20 spec'd cars, we used 5w30 but that's another conversation.

 

[FZ1]

Agree with 5k oci. Get it cleaned up prior to longer oci. You could also try some different brand oils for different cleaning.

 

[4WD]

+1 ... Or change filter

 

[Why]

I recall seeing this same phenomenon when I first changed the oil in my 99 Wrangler 4.0 right after I bought it at 36000 miles. I put in regular M1 10W-30, and within 1000 miles, it was jet black. The auto hobby shop assistant was chatting with me when I drained it out at 3000 miles (yes, back in those days), and was chastising me for running the oil too long because it was so black. His jaw dropped when I told him how long I had run it.

 

[Tony10s]

Originally Posted By: KCJeep
We put one of my favorite filters on it, a Motorcraft FL-400s. I will keep an eye on it but a change of filter at 5k might be warranted by the looks of things. There is no way he is going to do a UOA, which is why the EP was one of my recommendations for a 10k run.

I am surprised at how much "cleaning" it is apparently doing in an engine that was not particularly dirty as far as we know. And I am not a Mobil guy by any means but I admit I am impressed. The engine runs like a top, there is no external indication of contamination so I really think it is just getting crud loose. I am certain it is not a "sludger" though, so early OCI's are not warranted IMO.

Like all our 5w20 spec'd cars, we used 5w30 but that's another conversation.

Sounds like you have a good plan.