Loss of power only under heavy load.

[cross4u]

Hi there, I'm new to the site. I have a 03 with a 6.0 with 75,000 miles. The truck runs good when I'm driving with no load. As soon as I have a heavy load and going up an incline there is a thumping noise coming from under the hood. The truck starts to sputter, there is loss of power, and black smoke comes out. I don't know what this might be, can anyone point me in the right direction? Thanks Salhttp://www.powerstroke.org/forum/images/smilies/dunno.gif

[oasis04]

Welcome to the org.

I know there are some very knowledgeable people here who can help you.
Unfortunately I am not one of them.

[wildfingas]

Originally Posted by oasis04

Welcome to the org.

I know there are some very knowledgeable people here who can help you.
Unfortunately I am not one of them.

You just wanted to post so he could see your stable of trucks!

How about when you get on it without a load. Maybe when you just feel like rippin on it? What are you seeing for boost? Maybe a sticking turbo. If you are getting black smoke that is a sign of over fueling which is why I would say a the vanes are possibly coked up.

[cross4u]

I stepped on it without load and it gets up and goes. Its when there is a load and the truck has to pull is when the thumping, or knocking under the hood begins. There is loss of power and black smokes pours out.