Blue/ white smoke ISX15

[tree98]

I would start by pulling the aftertreatment system apart and inspecting the DPF and DOC. The DPF is likely cracked if it's puffing smoke. You're either going to have to replace the DPF or at the very least get it baked and flow tested so either way it's gotta come off.

The DPF collects the smoke that the engine is producing, while you have the cans off, start the engine and see how much smoke the engine is actually producing. Might be a lot more than you thought.

Having a look at the face of the DPF can tell you a lot about the possible source of the smoke your seeing.Blue colored smoke is likely from burning oil, does it use quite a bit of oil ?Take pictures of the DPF face and post them here.

Has it been using coolant?

Will the engine pass a leakdown test using insite?? That's extremely important on these common rail engines.

Leaky injectors can cause severe damage, everything from heavy fuel impingement to catastrophic fuel pump failure.

Also don't use aftermarket injectors!! That's a huge mistake on an ISX, I know they are expensive from Cummins but trust me it's worth it in the long run.

How many miles are on this engine? The fuel pumps need rebuilt every 400K miles too by the way.

There's a list of things that will get you started.