Black oil in motor
Black oil in motor
Hello everyone. I wanted to get a solid answer regarding the condition of what to do in regards to my motor oil. I have a 88 iroc vert with a 5.7(swapped by previous owner). The owner had this car for about 9 years and had the motor rebuilt when he first put the motor in. In the 9 years he roughly drove the car 3000 miles. I bought the car last year and I havent drove it much either, maybe 400 miles at most.
The car mostly sits due to me not using it as a daily driver. When I got the car I immediately changed the filter and oil with a pureone filter and royal purple oil. The oil turned black quite quickly. My question is, what can I do? I don't drive the car often at all. At most in the summer only. During the rest of the year it sits and I start it up about once a week. I am also thinking its a fuel issue, the fuel might be to rich(I have a superram). I also thought about putting one quart of atf fluid, but don't want to risk blowing a bearing. My best self suggestion is to run synthetic, but this won't do much help because I BARELY drive the car. If I would have driven the car more the synthetic would have slowly cleaned the internals, due to synthetics nature. At this point im stumped
. Any suggestions would be greatly appreciated. Thanks
The car mostly sits due to me not using it as a daily driver. When I got the car I immediately changed the filter and oil with a pureone filter and royal purple oil. The oil turned black quite quickly. My question is, what can I do? I don't drive the car often at all. At most in the summer only. During the rest of the year it sits and I start it up about once a week. I am also thinking its a fuel issue, the fuel might be to rich(I have a superram). I also thought about putting one quart of atf fluid, but don't want to risk blowing a bearing. My best self suggestion is to run synthetic, but this won't do much help because I BARELY drive the car. If I would have driven the car more the synthetic would have slowly cleaned the internals, due to synthetics nature. At this point im stumped
. Any suggestions would be greatly appreciated. Thanks Joined: Oct 2007
Posts: 2,606
Likes: 6
From: Kemah, Tx
Car: 1991 z28
Engine: Turbo 310
Transmission: T56
Axle/Gears: D44
Re: Black oil in motor
i run rp and change it every 2500 miles, its ALWAYS dark brown/black when it comes out, i think the purple color goes away after juts a few minutes of driving
Re: Black oil in motor
The problem isn't it doesn't stay purple, but the oil turns black within minutes of driving. I'm assuming the internals are either really dirty or extremely rich fuel in the oil.
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Joined: Jun 2006
Posts: 128
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From: Colorado
Car: 1992 Rally Sport
Engine: 355CI
Transmission: T-5
Axle/Gears: 10bolt stock gears
Re: Black oil in motor
engine flush... from having the same oil in it for 9 years... the additives in the oil stopped working... thus the oil just sat there.. and collected dirt.. from where ever it was touching... also.. your 400miles in a year... makes your oil dark..
so change it every three months.. weither your driving it or not... thats why its 3,000 miles OR 3 months
but go to an oil changing place and get an engine flush (do not go to jiffy lube if you love your car.) Try to find a place that knows what they are doing and can explain to you what the engine flush does.. if they try to bs you ... go somewhere else... if they tell you the facts and how they do it... i'd get it done there..
i've done this on several cars... and it cleans the oil right up... cleans the carbon build up where the oil has ran and turned into carbon...
And i doubt its fuel in your oil... but drain some out onto your finger and smell it or pull the dipstick tube out and smell it if it smells like fuel.. and not oil... your rings are shot on the pistons...
so change it every three months.. weither your driving it or not... thats why its 3,000 miles OR 3 months
but go to an oil changing place and get an engine flush (do not go to jiffy lube if you love your car.) Try to find a place that knows what they are doing and can explain to you what the engine flush does.. if they try to bs you ... go somewhere else... if they tell you the facts and how they do it... i'd get it done there..
i've done this on several cars... and it cleans the oil right up... cleans the carbon build up where the oil has ran and turned into carbon...
And i doubt its fuel in your oil... but drain some out onto your finger and smell it or pull the dipstick tube out and smell it if it smells like fuel.. and not oil... your rings are shot on the pistons...
Last edited by 92RSStud; Mar 23, 2009 at 06:56 PM.
Junior Member
Joined: Feb 2008
Posts: 84
Likes: 0
From: Blairsville Ga
Car: 1988 IROC-Z
Engine: 305
Transmission: 5 speed
Axle/Gears: 3.08 posi
Re: Black oil in motor
If you start the car once a week do you drive it and let it get fully hot? Or do you just run it at idle? It causes alot of condensation if you just idle it and not drive it. This may contribute to the black colored oil.
mike
mike
Senior Member
iTrader: (1)
Joined: Jul 2007
Posts: 1,141
Likes: 2
From: MA
Car: '87 IROC/'68 SS
Engine: 5.7L/350
Transmission: 700R4/Muncie 4-spd
Axle/Gears: 3.27 9 bolt / 3.31 12 bolt
Re: Black oil in motor
Yea it's probably sludged but you don't want to loosen it up since it's not hurting anything. I had a buddy that bought a sludged FB. He put flush in it (against my advice) and it spun a bearing two days later. If it's ain't broke, don't fix it (and don't waste your money on purdy purple oil) :-)
Joined: May 2004
Posts: 2,262
Likes: 1
From: houston
Car: 83 POS monte carlo 2015 chevy P/U
Engine: 92 5.7 tpi 5.3
Transmission: 700r4 6L60E
Axle/Gears: 2.42 too high
Re: Black oil in motor
i feel running a synthetic oil in a motor that sees very little road time is a waste of money.
like was mentioned, there is also the time factor to consider.
i have a friend who drives his truck very little, about 2500 miles a year, so he was only changing the oil once a year. and he had a sludge problem, again. he was loosing oil pressure with only about 12,000 miles on the motor. he dropped the pan and the pickup was clogged with sludge.
this was the second time it happened with this truck. he was lucky this time, the first time he spun a bearing.
he uses the same oil and brand of filter in his daily driver and the pan was clean with almost 200,000 on the motor, the oil & filter in it gets done every 3000 mile or 3 months.
you would probably be ok with 3 a year.
change it when you first start driving it, change it during the time your driving it, and again right after you park it for the year.
when you change the oil, get the motor fully warmed up before you pull the plug and let it drain for at least 10 minutes, the dirtiest oil is the last drop that comes out.
like was mentioned, there is also the time factor to consider.
i have a friend who drives his truck very little, about 2500 miles a year, so he was only changing the oil once a year. and he had a sludge problem, again. he was loosing oil pressure with only about 12,000 miles on the motor. he dropped the pan and the pickup was clogged with sludge.
this was the second time it happened with this truck. he was lucky this time, the first time he spun a bearing.
he uses the same oil and brand of filter in his daily driver and the pan was clean with almost 200,000 on the motor, the oil & filter in it gets done every 3000 mile or 3 months.
you would probably be ok with 3 a year.
change it when you first start driving it, change it during the time your driving it, and again right after you park it for the year.
when you change the oil, get the motor fully warmed up before you pull the plug and let it drain for at least 10 minutes, the dirtiest oil is the last drop that comes out.
Last edited by DENN_SHAH; Mar 24, 2009 at 02:34 AM.
Joined: May 2004
Posts: 5,338
Likes: 73
From: Lexington, SC
Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: Black oil in motor
This can be exacerbated by a low degree t-stat.
Junior Member
Joined: Dec 2009
Posts: 37
Likes: 0
From: Whistler BC
Car: 85 trans am
Engine: 305 tpi
Transmission: 5 speed
Re: Black oil in motor
Exactly. This is the worst thing possible for an engine. One of the byproducts of combustion is water and it's going to get into your crankcase. You've got to run it long enough for the oil to get above water's boiling point so it can escape. Otherwise that water in your oil forms acids and sludge.
This can be exacerbated by a low degree t-stat.
This can be exacerbated by a low degree t-stat.
Joined: Feb 2002
Posts: 3,462
Likes: 4
From: N. Illinois
Car: 92 GTA/ 00 TA
Engine: 383/350
Transmission: 700R4/T-56
Re: Black oil in motor
If you can't get it up to temperature then don't even start the car.
Personally, I would do the slow clean with synth. Start cleaning when you can start driving. I bought a sludged car before and it took 3 oil changes before it became normal.
Personally, I would do the slow clean with synth. Start cleaning when you can start driving. I bought a sludged car before and it took 3 oil changes before it became normal.
Supreme Member
iTrader: (7)
Joined: Jan 2009
Posts: 1,176
Likes: 4
From: Moneta, VA
Car: 88 GTA
Engine: 305 TPI
Transmission: WC T5
Axle/Gears: BW 9-bolt 3.27 posi
Re: Black oil in motor
I'd be a little afraid to run a flush through the motor. Here is what I have done in the past: It costs a few bucks, but I think it is a safe way to go. Drop the oil and filter. Replace the filter, add fresh oil, and run the engine until it reaches operating temperature. Shut down, drain and refill with new oil. Repeat until the oil stops turning black. Then drop the oil and filter and replace with new.
I did this on a Buick V6 with 120K miles, and it cleaned the engine right up. IIRC, I went through about 20 quarts of oil, and a couple of filters, but the engine cleaned up without any risk of damage. I am planning to do this on my 138K mile GTA.
Now you don't have to use anything beyond the recommended oil for your engine, because it will only be in the engine for a few minutes. Once you got your oil clean, make sure you periodically check it, and be sure to change it when the color starts to darken, regardless of the actual mileage.
I did this on a Buick V6 with 120K miles, and it cleaned the engine right up. IIRC, I went through about 20 quarts of oil, and a couple of filters, but the engine cleaned up without any risk of damage. I am planning to do this on my 138K mile GTA.
Now you don't have to use anything beyond the recommended oil for your engine, because it will only be in the engine for a few minutes. Once you got your oil clean, make sure you periodically check it, and be sure to change it when the color starts to darken, regardless of the actual mileage.
Joined: Feb 2002
Posts: 3,462
Likes: 4
From: N. Illinois
Car: 92 GTA/ 00 TA
Engine: 383/350
Transmission: 700R4/T-56
Re: Black oil in motor
I prefer to run 1 quart synth mixed with the rest of the oil.
Next change, 2 quarts synth
Next change, 3 quarts synth
You get the idea. It's a slow clean.
Next change, 2 quarts synth
Next change, 3 quarts synth
You get the idea. It's a slow clean.
Re: Black oil in motor
Ternandes, Viprklr, you guys have some good ideas. I can't wait until it gets a little warmer so I can atleast do something. Flushing the engine would be the last resort, I know the havoc that runs with those. I might also add 1 quart of tranny oil in the mix...
Supreme Member
Joined: Nov 2009
Posts: 1,255
Likes: 54
From: Lincoln, NE.
Car: '87 IROC
Engine: 5.7 Vortec w/ factory TPI
Transmission: WC T-5
Axle/Gears: 3.45 Posi
Re: Black oil in motor
I store my car in the winter and don't pull it out until the spring. In the fall I take it for one last good romp then change the oil right there in the building where it is stored. Been doing this for a few years now and have not had any problems yet.
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