I will change the oil in my 94 bronco 110k every 3000 mile. but when i check it at 1500 or 2000 its dark dark black and lost about a quarter to half of a quart. Any worries?

 

Have you changed brand or weight of oil?

 

Sounds like maybe you have a lot of blow-by, have you checked compression, if so what do the numbes look like????

Are you certain your air/fuel ratio is ok???

Is the PCV system intact & working???

Are you using the specified weight oil, for your driving conitions????

Has this condition come about suddenly, after some event, or slowly over time????

Also may also be helpful to know which engine is in the Bronco.

Just some thoughts to ponder.

 

Some oils darken quicker than others and some engines with that many miles have some blowby. Dont worry too much about it. I'll be willing to bet you that a used oil analysis on that 3000 mile dark oil shows enough life left to go the recommended 5000 easily. Chevron Delo 400 in our old BMW darkens almost immediately, yet tests within spec at 6000-8000 miles. A pint or less consumed in 2000 miles is also nothing to worry about. There are new engines, such as some of the Super Duty V-10's, that use more than that.

Jim

 

I have a 351w and as far as the compression, air/fuel, pcv i dont know if there work properly. the weight im using is 10-40

 

Well, still a lot of unknowns, to try & reason out, IF you may have other problems or not.

Given your location, I don't see any reason to be using a 10W-40 oil.

These oils don't have as good a base stock, as lighter weight lubes & thus typicaly, to compensate for the lower quality base stock, contain more viscosity index improvers, which if not good enough quality, can in turn break down/shear down from heat & use to a lower vscosity value more quickly & cause the oil to turn dark.

When this color change/oxidation/breakdown begins, it can be a vicious cycle, that builds on itself, to hasten more oxidation breakdown.

So this may be one possibility why your noticing such a dramitic change in your 10w-40 oils color, in this engine.

Now if you also have other problems, like fuel dilution of the oil, say from an overly rich air/fuel mixture, from the likes of leaking fuel injectors, or maybe too much fuel pressure, from a acting out pressure regulator, or maybe you have a clogged air filter, causing a overly rich air/fuel ratio, or maybe a damaged or misfittng air filter element, thats letting dirty air into the engine, or a stuck PCV valve, or oterwise misbehaving PCV system, thats not properly venting the crankcase & dirtying up the oil, or you have excessive blow by, from worn or carboned up & stuck rings, or from any combination of the above, you might also see similar results.

SO, imo you need to do some checking of the systems listed & make sure they're working right & maybe look to a better quality base stock oil, of the right viscosity for this engine operating in your areas temperature range & your driving conditions & habits & see if things improve.

Certainly the amount of oil consumed isn't abnormal & it turning dark isn't abnormal either, as Jim has pointed out, but as I interpret your description of it's color as being really black in a short time, suggests to me, maybe something isn't right.

Just some more thoughts to ponder.

 

Don't worry about color. Testing is the only way to find out if oil is bad. Other than that, follow manufacturers instructions.