Well I'm almost done with my first "new" ring fix for a Z06. Seems strange this is only the 2nd LS1/LS6 car that has complained about oil consumption where I work (in 2 years). The first one I reringed received just factory replacement rings as the new rings weren't even made yet when it was done. Maybe the problem isn't as widespread as corvetteforum.com members make it seem to be. This Z06 had been using 1 quart of Mobil 1 5W-30 oil every 600 miles. It has 8000 miles right now at the time of the ring fix. No oil in the intake plenium on this one like you see on LS1 cars.

I feel this one may have been driven extremly hard, as the front brakes are completly worn down to less than 10% useful life left, the tires are about 50% worn. Kinda excessive for 8000 miles I thought. <img src="gr_images/icons/wink.gif" border="0">

Anyways onto the repair...
We had been monitoring the oil consumption from before the new ring sets were available. We knew where it was going, the parts just weren't available at the time to make the repair correctly.

The pistons/connecting rod assembly's can be removed from the C5 without removing the engine assembly. I used an engine support bracket assembly made for C5's to hold the engine up while the front subframe is removed. The heads, intake and PS pump/brackets all are removed very easily, no interference problems at all. Everything on the topside was easy to get to, had no clearance problems with anything.

To pull the front subframe takes a little work, but with the right tools its a breeze. Once the subframe assembly was removed, the oil pan is very easy to remove, along with the oil pickup tube and windage tray.

Removed all pistons/connecting rods, of note was allot of carbon buildup on the tops of the pistons. I removed all the carbon so that there wouldn't be any pre-detonation issues down the road, it also makes assembly easier with completely clean parts. <img src="gr_grin.gif" border="0">

The new ring sets come with all the rings, top compression ring, revised 2nd compression ring, oil rings, and a revised oil expander ring. GM wants only the 2nd compression ring replaced and the oil expander ring to be replaced with the revised units. The top compression ring and the 2 oil control rings are to be reused, this is to minimize break-in time for the new rings. The 2nd compression ring has been revised in that it has a "step" built in that actually makes it more of a scraper to help scrape excess oil off the cylinder walls. The revised oil ring expander has more tension than the stock oil expander ring, went from 9lbs to a stiffer 13lbs.

All the ring replacements went real well. Made sure to double check all my ring end gap locations, I like the compression rings 180 degrees apart, the oil control rings I set at 45 degrees apart from each other, and its set up so that no to ring end gaps overlap each other. I do each piston exactly the same as the next.

I always replace the connecting rod bearings whenever I have an engine apart, no different for this one. All new connecting rod bearings went in all along with the pistons each in the same cylinder which removed from. Torqued all the rod bolts to specs, reinstalled all of the bottom side of the car.

What I ended the day with today was installing the cylinder heads, exhaust, valvetrain and rocker covers. Have a few things to put back together tomorrow and she should be done <img src="gr_stretch.gif" border="0">

I think I get paid a whole 10 hours of labor for all this work from GM, hardly worth my time, but at least I get to drive it when I am done <img src="gr_images/icons/wink.gif" border="0">


-Joseph

 

excellent info. :thumbup:

 

Joseph, I too am a GM tech, I liked your post.
As far as your warranty labor you didnt flag for the thread repairs(hint,hint) or you could challenge that service time labor. But I agree those cars would be cool to work with, even if you dont break even sometimes. Later.

 

[quote]Originally posted by LS1derfull:
<strong>Joseph, I too am a GM tech, I liked your post.
As far as your warranty labor you didnt flag for the thread repairs(hint,hint) or you could challenge that service time labor. But I agree those cars would be cool to work with, even if you dont break even sometimes. Later.</strong><hr></blockquote>

Thanks! I did end up getting flagged for 20 hours, the labor time had been upped since the last time I had checked it, I also got some OLH for cleaning the excessive carbon deposits from the oil burning. I think 20hrs is fair for this job considering I did it without removing the engine. The 18 mile road test is what makes this kind of job worthwhile <img src="gr_grin.gif" border="0"> <img src="graemlins/z06.gif" border="0" alt="[Z06 Corvette]" />

 

My 01 Z06 only seems to burn oil at Track events when the car gets around 15-25 hard laps. On the street it never burns oil. I run 7.5 quarts at the track so I will not run into low oil problems under hard g's.