GTX separation?

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May 27, 2002
Just changed the oil and I see a dark substance stuck to the bottom of the container in all 4 bottles. What is this stuff...moly, an additive? Do I want to drain this into my motor? And if I do will it settle to the bottom of my motor? [Freak]
Sounds like a bit of additive separation. Generally, this is not a good thing. I would use some other bottles as some performance is now sitting at the bottom of those bottles. I'd also contact Castrol. You might get some good freebies from them
I also have noticed the dark substance at the bottom of quart bottles and 5 quart jugs. I do not think this is any additive seperation. Could it be that castrol is still using a Group 1 oil and is adding a top notch additive package to meet the SL specs? Would the lower quality base oil cause the dark gunk at the bottom of the containers? I still think castol makes a top notch oil.
i dont think that Castrol is using a group I base oil in its GTX brand, and i do concur that ts probably additive separation. Is it thick or is it really black or more grey like? Although Castrol does make high quality oils, they, like every other company are human and with being human, comes mistakes. And every company has bad batches that go out. Perhaps this is what has happened. [Off Topic!] Most oil blenders (remember Castrol is only a blending company. they buy their base stocks from other oil companies, maybe now just BP.)are using group II or group II+ oils and whether group II & II+ oils a re hydrocraked or not i dont know. I think that the difference between group II+ and III oils is a fine line.
It looks like a dark clay color-somewhat grey. Funny thing is I have seen this in almost every container of Castrol I have purchased. Another interesting note- Castrol has purchased some base stock in the past from Chevron. This was stated on a Chevron web site listing customer bases.
I have to agree with the additive separation idea. I see this in the bottoms of several brands of oil, including the Mobil Delvac-1 that I use. I think it's visible in many oils that use light colored containers. I don't see that it causes any problems but it would be nice to get all of the additive that you payed for.
I'd think you'd want to put it in, although it's floating around like a suspended solid. Either it dissolves when heated and does something or gets filtered out.
I am not a lubrication chemist, but it seems to me that there has to be something seriously wrong when chemical additives separate out and settle to the bottom of an oil container. Remember when people pointed to oil additives that contained PTFE and said, 'If it says you have to shake the container before adding, don't buy it.' Well, if I have to shake a bottle of oil to mix whatever chemical additives are in the oil, before I put the oil in my car engine, I am disturbed. Heck, I remember when my Saturn new car dealership was selling oil additives containing Graphite. I bought a bottle and put some of this oil additive into motor oil, and left it for several months undisturbed in a clear sealed glass container on a garage shelf. The graphite never settled out. Seems to me that big oil companies can do as well.
Just another thought on this subject. If it fact Moly is settling out of the oil, then perhaps more work needs to be done to find a way to keep the Moly in suspension. Or if there is a serious settling problem with Moly, then perhaps some form of chemical friction reducer and wear reducer needs to be used instead. Seems like the Moly should be in chemical combination and should not settle out. Maybe some companies are using some poor quality Moly additive that is not in the proper chemical combination.
If the Moly, or whatever is settling out of the oil, can be stopped by the oil filter, then the oil filter would plug up sooner and the additive would do nothing for the engine. Some people above were suggesting that the oil could be just a bad batch, but then another guy said that he had noticed it in a high priced motor oil from another manufacturer. Is there a serious problem with Moly or another additive settling out of motor oil?
Nope, it is a thick fluid inside the bottom of the bottle. Leave it on its side and this STUFF will slowly move. Maybe I am done with GTX. [No no]
I haven't noticed such things from my bottles of GTX..or maybe I'm not paying enough attention [Smile] Somehow I doubt they'd put anything in that would hurt the engine..
The moly used in most motor oils can not settle out. It is not in suspension and is not solid particles. It is in solution and only molecules are present, not particles. Molybdenum disulfide is the particles--this works well in grease and in suspension in gear oil. Molybdenum trialkyldithiophosphate is dissolved, and invisible, in motor oil and hydraulic oil (and certain grease and gear oil). Don't know what you saw in the bottom. Ken
I,ve noticed that black stuff too when I bought and used the GTX 5w30 for the first and last time a couple of month ago. I'm used to use Canadian tire oil in the past and I never notice that stuff.Even if I had oil sitting for months before being used.That looks to me like charcoal dust !!! I bought for my next oil change the Petro Canada Supreme 10w30 , that oil look good on paper and we will see, Castrol..never again, they can come with the reason they want, I dont know why but I never trusted them, gut feeling, and syntec played a big part.
Sounds like we need to send this suff off to Terry for an analysis! I am sure he could solve the mystery with a sample. For the record I have never seen anything in the bottom of my GTX and I have used tons of this stuff! [ June 13, 2003, 06:29 PM: Message edited by: TR3-2001SE ]
I noticed it on the last oil change, but only cuz you guys made me look! [Mad] Oh well I just dumped in the remaining 3 qts. The 160,000 mile 4Runner doesn't know. [Wink]
I sometimes used to notice a bit of sedimentation at the bottom of my bottles. Later I discovered it was just dirt at the outside the bottle which looked like a bit of sedimentation on the inside when I help the bottle up to the light...
Well,thats all I need to hear.I was about to start using Castrol since I cant get Chevron anymore.I think my only other choice now is Havoline. [ June 14, 2003, 08:01 AM: Message edited by: BlueOvalFitter ]
HUH...Never seen any stuff on the bottom of my Mobil jugs...and I do a few vehicles with it...and check the bottom every time...after being on this board for a while...nada in those of my customers requests Castrol GTX in his Honda for oil changes...will check next time.
This all makes me glad that I have switched to Schaeffer's Oil. I didn't notice anything in the bottom of the oil containers of the Schaeffer's. And Schaeffer's has a lot of Moly. But I never had a problem with Chevron Supreme either, and it has a small amount of Moly, right? There does have to be some sort of problem, because more than one guy has noticed this stuff at the bottom of oil containers. I agree that if Moly is in a molecular form it should not settle out. Heck, the graphite in a oil supplement that my Saturn dealership used to sell would not settle out. Maybe some companies are using a cheaper type of Moly additive, or there is something wrong with their base oils or the way they formulate their additive package. If I was using any brand of oil, no matter how highly rated that oil was, and I noticed stuff like that in the bottom of the bottle, I would switch to another brand.
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