'02 2500HD 6.0l

[elbud72]

I bought a used 2500HD 6.0l w/ 85K miles. Now have 115K. It's been a good truck til recently. I went from not using any oil to using 1qt every 1500 miles or so. Not sure what the cure for that is. It now takes 3-4 seconds before the tranny goes into drive from park or reverse. (It's an automatic) Is this a major fix or an adjustment? Also, when making turns at 10-15MPH I get a loud clunk from under the chassy. It's almost like it's under the floor board of the passenger side. If I drive down the street swerving from left to right real fast I can make it clunk consistently going left and right.

 

I apologize if these problems have already been discussed but I didn't have much luck using the search on the forum. My mechanic has been of little help so I was hoping ya'll might have some suggestions.

 

Thanks.

[mmmikkke]

My '95 K3500 (1-ton 4wd single rear wheel) developed a similar sudden increase in oil consumption at around 120,000 miles. Turned out to be the intake manifold gasket. It started fizzing green bubbles (coolant), had it replaced, and the oil consumption problem went away.

 

Not sure if the 6.0 suffers from the same possibility, though.

 

The clunk could be the torsion bar mounts. Put the truck on a hoist and inspect the bushings that the bar goes through, and inspect the keys (where the bars are adjusted). Maybe it's worn a groove and it pops out of the groove occasionally, making the clunk.

 

As far as the trans goes, have you ever changed the fluid and filter? That would be the first thing to try since it's so cheap, compared to anything else about the trans.