A little ground work first. This motor is a turbo with no more than 4k on it. I have changed the oil probably three times in the last year with break in and all. The current oil has maybe 500 miles on it and is jet black once more. This has happened every oil change. I will say there where some carbon deposits on top of the pistons( I have the head off right now) very small ones which came off with a liitle WD40. And the truck was running a little rich for a while.
This looks like oil from a diesel engine I guess I could send it out for some lab work.

And lastly just to rule this out, I cleaned the crap out of the block after machine work and the head is brand new.

If your really seriously concerned, sent out a sample. It's like $20 or something for analysis. Otherwise I wouldn't worry too much. Color means far less than whether or not the oil retains it's lubricity.
Someone else may come up with some other things to say about it but unless they can site a specific example I wouldn't take it too seriously.

Clay

I am a little, it's definetely not normal.

Then it's probably worth $20 for the peace of mind. If they don't say it's metal or coolant(they'll send you a big list with lots of numbers on it) then I wouldn't worry at all. Please post the full report when you get it done.

Clay

All three of my 2.6 turbo motors seem to blacken the oil rather quickly. I am running regular Valvoline in two of them and Max Life in the one with 100000 miles on it. I have heard of useing Castrol motor oil to prevent coking of the oil in the turbo. That may be what turns the oil black so quick. I sure someone will chime in with better info.

That's what I was waiting to hear, funny I actually had used castrol last oil change.

FWIW - My T-bird Turbo Coupe used to blacken the oil, even synthetic, before the rebuild, after the rebuild, within a few hundred miles of of every oil change.


Jonathan

Are you letting the motor idle several seconds before shutdown? This is necessary to allow the turbo to cool and avoid oil coking in the hot center section. Even with that precaution, the oil cokes some, which is why you change the oil religiously at 2.5-3k mi on a turbo. You also have much higher combustion pressures, which causes more blow-by past the rings, further contaminating the oil. Like a diesel, in other words, and diesels also require more frequent oil changes. I've run Castrol 20w-50 dino for eons, in turbo and n/a motors, and I swear by it. I ran straight 50w in the hot rod Fiat spider (12:1 compression), but that was overkill.

I might send out a sample for peace of mind, but I think you're fine.

On a related note, don't start your machine and let it idle in the driveway (not that you do, but just in general). As soon as you have oil pressure, its good to get underway (mellow). An idling engine will take much longer to reach operating temperature than one that is driven easily (no full throttle, high revs, etc.) The quicker the engine reaches operating temperature, the less blowby, the less acid formation in the oil. I see all kinds of people around here letting their cars idle for ten minutes or more on cold mornings, thinking that they are doing their cars good...

The cool down period for a turbo is definately important. I know that it is a bit of a pain when I'm driving my cummins unit and want to run in to the grocery or beer store, but I've tried to be pretty strict about letting it run for at least a minute before shutting it down. I'm going to wire in an ignition switch that reads temperature from the pyrometer and allows the engine to run after removing the key until exhaust temp reaches a safe level. Maybe you turbo guys could do the same...

You could just set yours up like I had my turbo. I got an "automatic" oil change about every fifty miles this summer, whether I wanted it or not. <img src="/forums/images/graemlins/ignore.gif" alt="" />
I thought I shoulda oughta fix it <img src="/forums/images/graemlins/notooth.gif" alt="" />