Smoking Duramax

I have a 04 Duramax with 60k miles on it. I recently put Zmax in the oil and a few days later it started smoking. It doesn’t smoke much at speed but when I let it idle it gets worse and worse. The smoking has been increasing. No the cloud in just like a WW11 smoke screen. It is at a shop and they first thought it was the Zmax. I changed the oil and filter three times to clear it up. It got worse. They checked the injectors and found one bad athen they checked it again and that one checked ok but two others checked bad. What in the world could be the problem???

Try replacing the PCV valve. Oil is most likely getting sucked up into the engine through it.

It would help if you told us what color the smoke is.

Also try changing the air filter.

When I worked as a truck driver, anytime my trainer saw a truck bellowing smoke, he would say the words “blown turbo.” I wonder if the Zmax may have damaged your turbo.

Why did you put the Zmax in there to begin with?

I believe that the Zmax has damaged your engine. Zmax must be added in “small” amounts. If you added more than 8-10 ounces then you added too much. This stuff is considered snake oil by a lot of mechanics including me. It’s tantamount to pouring engine cleaner in your engine. I don’t recommend adding any additive at all because of what you are now experiencing. I suspect that Zmax breaks down the lubricating qualities of engine oil. That’s the last thing that you want to happen.