Black Oil Means What ?

[Idrinkmotoroil]

I decided to take the plunge and run Redline 10w30 in my car to test out against past oils that I've used. So I did an oil change this evening. I just got through running a short run of Castrol Syntec 5w-40 Belgium made European formula. This oil has been in the car for maybe one month maximum, probably less than 2,000 kms on it with at least 50% highway miles. Temps in our area lately averaged 10C for the most part. Mobil1 10w30 used before it. I noticed that this 5w-40 oil was extremely black, and looking in the oil cap fill area inside of the valvecover it looked black. The weird part that alarmed me was that when I went to check the oil level of the brand new Redline 10w30 that I just put in the engine. When I checked the dipstick it looked very black already and I haven't even started the engine on this oil. It looks like dirty oil already !. I tried pouring clean oil down the dipstick hole and that cleared things up briefly, but a few more checks of the dipstick and it darkened up again. This has never happened on this car before. In the past I've actually had trouble reading the oil level on an oil change because it always looks too clean and it doesn't show up too well on the dipstick, but this time it looks like the oil just finished a long duration run.

What can I make of this new discovery ?. Some people say dark oil is doing it's job, but to me it looks like it's working terribly. I don't think the Castrol Syntec 5w-40 has worked very well. Luckily I took a sample for analysis which I will send in. But to me this is not a good sign. I'm glad I've gone with Redline at least on this run, but it's off to a dirty start.

Some information for everyone. I've put in 4.5 quarts on a 5 quart sump, I imagine that I can get another 1/2 quart in once I start the engine up and the oil filter pressurizes. It's too late tonight to run the car, so it will be tomorrow morning. The engine is a 2.4 Litre Turbocharged Dodge srt-4, daily driven, not hard driven at all. Engine runs well, spark plugs are extremely clean, new pcv valve, new air filter, well maintained, never run more than 3,000 mile OCI's on it. She is going for a trip on the highway tomorrow for a few hundred miles, hopefully that might help. In summary I've never seen my oil this dark/dirty as long as I've owned the car, it has 38,000 kms on it.

any info or advice is appreciated
thanks !

 

[TallPaul]

Might be interesting to put a drip or two on a white file card, let is soak in, and see if you get much of a ring around the center part and how dark it is on the card.

Wonder if the Castrol has something in it that would clean the engine out causing the oil to dirty quickly and now maybe the residual has colored the Redline. IIRC Redline is a bit dark in color. So maybe all is well.

 

[Idrinkmotoroil]

yes Redline does show up a bit darker in virgin form than say Mobil1, but this is too dark and has a residue to it.

I guess the question is if Castrol was actually doing some cleaning or if it burned up, leading to the dark residue in the engine.

 

[Triple_Se7en]

Quote:
I just got through running a short run of Castrol Syntec 5w-40 Belgium made European formula. This oil has been in the car for maybe one month maximum, probably less than 2,000 kms on it with at least 50% highway miles.

I'll bet you're still seeing cleanup from the Mobil-1. What color was the dipstick at the halfway point of the Belguim Castrol run ... lets say 1000kms?

 

[99]

Black oil is dirty oil. Not much more to it than that until you get your UOA results.

 

[oilyriser]

Is there any smell of gasoline in the oil? There's also a chance that something has just gone wrong, and the engine is getting too much fuel, and burning very rich. Also, track your fuel economy carefully, to see if anything has changed.

 

[Pablo]

First of all if any oil gets dark right away that just tells me it's mixing with oil remaining in the oil system. This will be especially apparent if the previous oil was doing some cleaning - and the next oil acts as a rinse. This is probably what happened in your case.

Hindsight being 20/20 - you could have either used the same oil again or a brief dino flush to save the expense of using killer expensive Redline as a flush oil.

Second, in general turbocharged gasoline cars will darken the oil the fastest of any gas vehicles, IMHO. Not only is the turbo and turbo bearings hard on the oil - the increased chamber pressures and blow-by will darken the oil.

That said - just because the oil LOOKS dark - doesn't mean it's done. Use UOA to determine that.

 

[bulwnkl]

It sounds like your Belgian Castrol behaved the way every crankcase-load of 15W40 HDEO I've ever had does. I don't know why the HDEOs get darker so much faster, but they always do. Every engine, every time. Makes it a little tough to believe it's sim;ly cleaning because it happens even on engines that have never run anything else (after factory-fill, of course).

I don't know why it turned dark. I was always told that dark oil is doing its job. Maybe ALL oils that don't darken are leaving deposits. I've never had RedLine get dark like an HDEO, though.

 

[newtoncd8]

From Quaker State:

A common misconception is that high quality motor oil should come out of an engine looking clean at the time of an oil change. Nothing could be further from the truth. If the oil is doing its job of cleaning the engine, then it should be dirty when it is drained. Quaker State® motor oil will start looking dirty a short time after it is put to use. In the case of diesel engines, the oil will look dirty within a few hours of operation. These are signs that the motor oil is doing its job of keeping soot, dirt, and other combustion contaminants in suspension to be carried to the filter or removed from the crankcase when the oil is changed. Quaker State® motor oils have been formulated to hold these contaminants in suspension until they can be removed with an oil and filter change.

 

[pscholte]

quote:

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Originally posted by Idrinkmotoroil:
I don't think the Castrol Syntec 5w-40 has worked very well.

---

idm,

I think just the opposite may be true. Assuming nothing has happened in your engine conincidental to the use of BC, what you may be seeing is an oil that is doing its job VERY well.

 

[Triple_Se7en]

Are you guys saying GC has more detergent than Mobil-1?

Another thought/reason for this black oil so soon may be attributed to a cold engine drain. I always drain my oil after running the engine at idle until operating temperature seems close to normal.... around 10-15 minutes in the backyard. Then I finally got smart & wear $1.99 auto-parts gloves to avoid hot splash.

 

[pscholte]

quote:

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Originally posted by Triple_Se7en:
Are you guys saying GC has more detergent than Mobil-1?

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Triple_Se7en,

Remember this is BC, not GC, and if it is designed for diesel applications, it almost certainly will have more detergency than M1 regular. (M1 EP and Delvac1 may be another story.)

 

[BlazerLT]

Did you warm up the engine to get all the old oil out?

 

[Idrinkmotoroil]

the engine was warm when I drained the oil. This morning I got another .4 quarts into the engine after turning it over for a minute or two. So it looks like I got most of the oil out of her on the drain. I also drove a couple hundred miles on the highway today, and the new Redline oil looks a lot cleaner than it did last night on the dipstick, so I think everything is fine. I think most of the black residue was present in the dipstick hole somehow and it took a bit of time to clear it out. Dunno why the dipstick hole would have that much oil residue in it. But it seems okay now, I hope to get some analysisd data on the Castrol and the Redline after the current run.

I think I will stick to a 10w30 oil though, the engine seems to be more responsive to the 30 weight that is in it now compared to the 5w-40. thanks for the information provided in this thread.

 

[99]

quote:

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Originally posted by bulwnkl:
I don't know why the HDEOs get darker so much faster, but they always do. Every engine, every time.

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Funny, I changed my Jeep's oil about a thousand miles ago and the oil still looks like it was just put in....Delvac 1300. My wife's Jetta has 2500 miles on the oil and it's still very clean....Rotella Syn. Both are gas engines. Diesel engines do dirty up the oil pretty fast though.

 

[Idrinkmotoroil]

later this week I'm going to throw samples of all three oils onto my BBQ grill and see what burns up faster - Mobil1, Castrol Syntec and Redline. Should be interesting.

 

[Dr. T]

It means 2 things:

1. Engine is dirty
2. Oil is breaking down either due to wrong viscosity for the application or run too long.

Sounds like you have #1, so it doesn't matter what oil you use, cleaning is taking place.

 

[firefighter6526]

I run Mobil 1 5w30 with a Pure 1 filter in my 03 honda four banger for around 4k miles between changes and the oil is always black as tar.

Is that a bad thing?

 

[Idrinkmotoroil]

quote:

---

Originally posted by Dr. T:
It means 2 things:

1. Engine is dirty
2. Oil is breaking down either due to wrong viscosity for the application or run too long.

Sounds like you have #1, so it doesn't matter what oil you use, cleaning is taking place.

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I would never have expected the engine to be dirty, running Mobil1 every 3,000 miles max, as my warranty needs 3,000 mile OCI's, and Mobil1 should go that distance easily. The only viscosity issue might be that the Castrol 5w-40 was too thick , is that a possibility ? since the engine calls for a 30 weight.

 

[Drew99GT]

quote:

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Originally posted by firefighter6526:
I run Mobil 1 5w30 with a Pure 1 filter in my 03 honda four banger for around 4k miles between changes and the oil is always black as tar.

Is that a bad thing?

---

Probably not. My Toyota 4 banger oil gets dark real quick.

I think Pablo is correct. What your seeing is old oil that's being rinsed off the inaisdes of the engine by the new oil. Occasionally after an oil change, I'll add oil then check it and there's black streaks on the dipsstick through the new oil. No worries.