Black Engine Oil

[Links]

Evening guys.. you don't know how much of a relief it is for the site to be back up and running..

Ok quick run down:

Got my car serviced on thursday last week..

The engine oil was changed to Pennzoil fully synthetic 10W40 I do believe.. before this the colour was still translucent but needed to be changed..

Anyways - on sunday went on the cruise up to Avoca via Old Pac and on the way home a couple of people started noticing that my car was blowing Brown smoke when boosting & probably @ high revs.

While I put this down to the car running rich - tonight I decided to check the oil as I hadn't looked since I had it changed.

Pulling the dipstick out I found it was almost jet black - and not translucent.

Intstant thought is Carbon (exchaust) has gotten into my oil and hence the colour of it.

My reasoning for this is a) I was running ~10psi all the way up but was finding the car would R&R so I only maxed it out at ~7psi by controlling throttle until it was time to leave and I put it to 0.6kg/cm^2 or approx 8psi which is what the standard solenoid runs. Because of the drive home we were on boost alot - it could have been forcing exhaust gasses into the oil and also possibly blow-by (i believe) where oil gets into the cylinder and hence the brown smoke..

now..

after having checked some other threads and also other sites - some people have commented that blackness or carbon can be a) the colour of the oil B) the oil cleaning crap out of the engine block c) exhaust getting into the oil some how (which is what I think has happened) probably because of the rings maybe??

I'm going to be changing my oil probably friday night or saturday morning with Motul 4200 or 8100 whichever I get my hands on first as I don't think the colour of the oil is good..

I need to get some feedback from people on what they think it could be.. The oil is not translucent anymore it's got a slightly grainy feel and is pretty black..

Any help would be great.. i'm quite worried as I think I might have f**ked a piston ring in the process of having high boost or driving relatively hard..

Thanks

Links

[Links]

I've decided to add a picture of the dipstick and what it looked like..

please - any help would be great people.. thanks

Links

not sure if this should be in Forced Induction or general Maintenance

[Abo Bob]

Doesn't sound good.

Does it still idle smoothly?

Sounds a little like blow by from broken piston. Stock ECU?

[Beer Baron]

are there any other problems with the way the car runs?

you should be able to tell if there is any fuel (exhaust) in your oil, you will be able to see it. Oil going black is no big deal. some oils go black quicker than others, some stay golden, some are purple so it's sometimes hard to judge just by the colour. if you really want to change the oil again, i wouldn't use turbolight 4200 it's a pretty crap oil. the 8100 is better. the penzoil that's in there is supposed to be very good. i know that is what my friend uses in his race motor.

my prediction is:

1. the smoke out the exhaust is just normal richness caused by the slightly higher than stock boost

2. the oil turning black is perfectly normal

oh, also how long was the previous service interval?

[AlexCim]

Oil being THAT black after 2 weeks is odd. Even at my 5000km change, the oil on the dipstick is still semi-clear

In the drain pan its black, but on the dipper its still clearish

[Beer Baron]

alex it entirely depends on the brand of oil. i've used oil before that is black 30 minutes after you put it in. and others that are still golden colour after 3 months.

[Scooby]

you might want to send a small sample away to get analysed. stick into a clean PET container ie plastic coke bottle, wrap tape around the screw top and package it well. most of the oil companes will do this for you, pretty sure duncan has had it done.

oil usually burns grey/white and fuel black, not sure what brown means. have heard various reports re pennzoil, a search should turn up a few comments.

not sure what 'car would r and r' means?

cheers

[MerlinTheHapyPig]

i use the same oil in my r32 (penzoil 10w40 semi-synth), goes black after about 3 or 4 weeks. This is ok, it means your oil is actually working, and absorbing carbon deposits.

Sometimes when going from mineral oil, to synthetic oils etc. the oil may have different additives which do a better job than your old oil. Might be a good idea to do another oil change if you're worried. But doesn't sound like there is a major problem or anything.

One sign of blow-by is popping out a dipstick. do you get this problem at all?

smoke could indicate a number of things. blown turbo springs to mind. Blue smoke indicates burning oil, black smoke indicates it's running rich.

[ImportAutoParts]

id sugest changing brand of oil....

i use penrite and it takes a good while to go dark but that has heaps and heaps to do with the condition of the motor itself....for example if the previous owner never changed the oil and let the inside of the engine cake up with old dirt and oil deposits it will stay like that for a while....untill you consistantly do a few hot flushes of the oil.....

like run the car very hot and then drop the oil...and then flush more oil through and continue to do that untill the oil flows clean...

it sounds as though it has been poorly maintained in the past....

[Links]

Thanks for the feedback people - after having spent all of last night and this morning both reading up and ringing people to find out different ideas i've formed some ideas, which can be seen in what you guys are also saying 2..

Bit of history first..

Car is 1998 - so it's only 7 years old, this is the first service it has had since owning the car - and the first oil change since it was complianced.

I think the boost pressure is possibly inrelevant to the issue..

from people i've spoken to as well as Eli i've got the following:

- Eli did a flush which should have cleared out anything in it (should have) - however i'm hesitent to believe this as some mechanics don't feel there is any need to do this.

- The oil that was put in when complianced was probably of average quality and may not have been doing much in the way of cleaning carbon in the engine and was letting sludge just sit there..

- Car has probably been doing street driving in slow traffic which tends to lead to more carbon/sludge buildup..

- When the Penzoil has been put in the Cleaning properties of this oil - which i'm sure are quite good - have started stirring up & loosening any buildup..

- Combining this with the fact that it was driven on the weekend relatively hard (not bouncing it off the limiter at all - never would) but still high boost sustained for increased durations it has proceeded to gather alot more crap from the inside than what it would under normal driving..

This leads to where i'm at.. an engine full of carbon particled oil..

We don't think there is anything wrong with the engine as the oil has not changed it's consistency, it hasn't got any sludge clumps in it and is probably still lubricating - while doing it's job which is to suspend carbon particles rather than letting them settle..

My current choice of action is to a) drop it back at the Mechanics and get him to take a look at it or b.) keep driving it for about 2 weeks to free up any other buildups and blocks than dump the oil, change the filter and put new oil in.

Currently this is what i'm leaning towards - and i'll probably be putting in Motul 8100 which is recommended on here..

Once i've done this i'll give it a week and monitor the oil..

now for the other things - brown smoke @ high RPM - we're puttin this down to running rich..

anyone got any ideas on what they think I should do??

Edited October 27, 2005 by Links

[Links]

Once again - thanks everyone.. was very worried last night.. have calmed down a bit now.. as ImportAutoParts said - could be poor maintenence previously - or usage of average oil which wasn't cleaning it out properly..

I don't think it's blow-by as my understanding is this is caused by oil getting into the combustion chamber?? yes?? no?? if someone wants to explain feel free..

If this was happening it would be blowing smoke at idle possibly - I haven't seen any Blue or White smoke which would indicate coolant or water getting into it and also an oil leak - which makes me think the rings are still ok and the gasket hasn't blown..

Cheers

Links

[JH32]

If you're worried about the motor could you not do a leak down / compression test?

Might put your mind at ease a bit ....

[Links]

Well yes.. I could.. however I don't believe that is the issue as it's not losing any power..

[Beer Baron]

yes compression test and/or leakdown test could be a good idea.

i really don't think it's anything. just your mind playing tricks on you

I'm sure Eli will happily take a look and make sure it's ok, or like you say give it a while and then switch to the motul if you like.

as for the smoke i'd say if it's happening whilst you are giving it some boot (under boost) then it's probably not blowby as the pcv is closed under boost (though i guess a little can still get through via the compressor inlet). i would bet it's just fuel. when i nail it in the GTR the car behind is practicaly enveloped in a cloud of smoke! when you are keen i'd say just go the ol' PFC or similar.

[Roy]

Oil colour???? If the oil is watery or has foreign fluid (coolant) then you have a problem. If its grey you have a problem. If you dump the oil into a clean pan and you can see paricles at the bottom of the pan thn you have a problem.

If your oil is black, well your oil is black. I wouldnt be at all worried. Mobil 1 use to come out of my engine black as the ace of spades. Castrol Formula R comes out of my engine black as the ace of spades.

I have no idea if these oils have a high detergeant level in them, but some oils do possess more then others. Oil primarily lubricates, but it also cools and cleans.

Quite frankly id be more concerned if my engine oil came out of my engine looking like new or transluscent after a few weeks or a few thousand kms. It may mean nothing, but could mean that all the very fine particles arent being captured in the oil, filters can oly do so much.

Again probably unrelated, but go grab some fine wet and dry and rub it on a metal surface. The resultant particles will appear to be black. The by products of combusiton/fuel etc are often black. The fact that your cooking oil goes black if you burn it/ repeatedly heat it. So why would you be alarmed if your engine oil turned black?

Just make sure its changed regularly with a good brand of oil, of the right viscosity, and if you are driving the car like a nutter at very high revs for sustained periods, well you may want to consider an oil cooler...but unless you have more power then std i wouldnt see that as a requirement.

[Links]

Thanks Roy - I just got set off by a combination of factors.. however i'm not a fan of things that go from one extreme e.g. clean oil to quite black oil within the space of 5 days - considering he did a "flush" as well.. sure it'll be black - however I wouldn't have expected this to happen for a while - but maybe the weekend driving accelerated what normally happens..

[Morgs]

My oil is like Roys, and it really dosen't take long to get to that stage. I change at very regular intervals 2000-3000km.

Compression or leakdown will confirm if its a problem with blowby. You might also want to throw it on a dyno and have a look at your AFRs.

[Roy]

My engine has a catch can and there is no blow by on my engine.

I have had two RB20s in my car now, and both have had plenty of flushes of very fresh fluid. Like a track day on a full sump, then the next weekend a new filter and sump for another track day. So th eoil would have done less then 400kms. Over kill? Most seem to think so.

But the oil is always pretty damn black. Even if the oil only had say 3,000kms or so of street use, it was always putrid looking.

So not saying its ideal, the way it should be, or indicaton that your car is in perfect condition. But i dont think its a cause for concern:)

[Links]

Put it on the dyno in August - was running rich and i'm sure it still is.. A/F dipped down to about 10.5:1..

[Scooby]

Oil colour????  If the oil is watery or has foreign fluid (coolant) then you have a problem. If its grey you have a problem. If you dump the oil into a clean pan and you can see paricles at the bottom of the pan thn you have a problem.

<{POST_SNAPBACK}>

if you you try to dump the oil and none comes out, then you have a problem