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Smoke... what is normal?

1193 Views 7 Replies 3 Participants Last post by  T_Bone
My (to my knowledge) non-chipped 02 w/ 68k miles puts out a fair amount of black smoke if I lug it while climbing a hill. Is this normal? Once I get RPMs up to 1700 or so the smoke goes away. It's not like I'm leaving a big black cloud behind me, but I can watch it smoke pretty good out my passenger mirror. None of the diesels I've owned smoked at all but none of them had more than 30k miles on them.

Main reason I'm interested is because I say my truck is not chipped, but I actually haven't inspected the PCM. I tried to look at it today but I didn't have time. I have quite a bit of noticeable spark knock type noise too so I'm wondering if the black smoke and the ping sound might indicate advanced timing.

I don't have my boost guage yet so I'm in the dark as to what kind of boost #s I'm getting. My power is good and I hear the turbo spool and whistle good once I get moving up a hill so I don't think I'm having any problems with the turbo.

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Ok, I pulled my PCM and I'm convinced the truck has never been chipped and I'd be very surprised if it's had any programming.

So this is a completely stock motor. What all could cause black smoke.

* Intercooler leaks
* Turbo problem
* Dirty injectors

What else? And what's a good plan for isolating the root cause?

Brand new AIS, so air filter is good.

Not dusted. Had a crankcase pressure test and the motor's tight. Tech ran the test twice and could only get about 3/4 inch or water.

What does the rattle sound like if an injector is bad? I have a pinging noise under load that sounds just like spark knock. It's worse in the cackle RPM range but even at higher RPMs it's there. The motor idles and runs smooth though, it's just noisy.

I already pulled the QD off and replaced it. I didn't notice any difference. The spark knock sound I get isn't related to lugging. It comes on strongest in 2nd and 3rd gear at about 1600 RPM (e.g. the cackle band), but I can still hear it up around 2k RPM too. I'm pretty light on the throttle and take my time getting the RPMs up. This is my first 7.3L so maybe this is just normal injector rattle, but I want to be sure.
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