I was working on the problem with my truck. Ruff idle, poor acceleration, poor fuel economy, surging, stumbling at higher speeds, anyhow I took off the EGR, cleaned it and put it back on and when I started it up it started putting out a whitsh smoke. Let it sit for a minute, started it up. Did it again, this time I let it run and it looked like it had maybe a greenish tint to it. Like it was burning anti-freeze. Any clues?

 

Check your radiator fluid and make sure it isn't down low. Then remove the oil filler cap and look for a white film around the inside of the cap. Those are good indicators that th HG is going or gone. The white exhaust is not a good sign.

When my HG in my 93 3.0L let go it did it pretty quickly.