Cummins smoke on acceleration

[IND2SLC]

Hi all, I have a 1995 Dynasty 40' with a mechanical Cummins 6CTA 8.3 300hp diesel engine. It runs great, plenty of power. However, when accelerating away from a stop, I'll see cloud about the size of a full grass/leaves trash bag of black smoke leaving the exhaust pipe. Only happens under 1/2 throttle or more, and only for a second or two. Once we're going, it stops. Doesn't happen at "campground speeds", thankfully. This isn't something I see in more contemporary coaches. Just replaced the air and fuel filters--again, it runs great with no apparent power loss. I understand how turbochargers work. But, is this smoke "normal" or appropriate for an engine of this vintage and application?

[rh2669]

I would check your crankcase pressure to make sure that your Pistons don't have excessive blow by.

[BOOZE TRAVEL]

Probably normal on the 12 valve. It takes a couple of seconds for the turbo to spool up and get enough air to burn the fuel.

[pasdad1]

The newer diesels don’t smoke because they have a DPF (diesel particulate filter) to catch the soot.

I don’t believe one of your vintage has this?

[Old-Biscuit]

Black Smoke is Raw unburnt Diesel

Turbo has to spin up and match air/fuel to burn clean

Not unusual

[Alpine36]

Slap one of these on your rig near the tailpipe, problem solved.

[oldmattb]

Our 1998 Monaco with Cummins 8.3 mechanical did that when I accelerated quickly. I never worried about it. I generally didn't accelerate quickly - I am usually very easy on the throttle.

[NevadaNick]

Its normal. When you get ready to sell it you can put this in the ad (smokes, drinks and stays out all night)