I've got a 2000 WS6 M6 with 52.7k miles. I recently bolted on the SLP lid w/ K&N, Mac mid's with on-road y, & loud mouth. The last 3k miles proved to be a PITA. I had to add 6 quarts of oil. I changed the oil at 52.6k and found metal shavings all over the drain plug. I've only had the car for 3500 miles and this is my first LS1 so I don't know what the normal amout of oil consumption or metal shavings should look like, but, 6 quarts is a problem.

When I initialy take off from a light at WOT, the car only makes a little gray smoke, more black than gray. But, when I let off and coast down 20mph or so and hit it again, that's when the magic happens. It looks like the car ***** a big gray thunder cloud. If I let off and drive like I have common sense, there is little to no hint at all of burning oil, just when I check the dip stick.

I've read about using a catch can, but I don't think the PCV is the main culprit. I've read about the valve seals as well. Is there any way to tell if the valve seals are leaking w/o changing them? I don't think blow-by is a problem because I have no fouling of the plugs or miss-fires (confirmed with AutoTap). I will be performing a compression check this week though.

Any help you guys can offer is appreciated.

 

'00 WS6 here.... did the MAC's...H/C blah,blah....same story. Catch can eliminatd the thunder cloud on accel/decel 99%. Always gonna have some blowby w/short skirted POS hyperujunk-ed pistons.....but 6 qts. is too much in 3k miles.

Do a leak down to help determine whether you've got seal/guide issues

A small amount of meticular looking goo is normal on the drain plug "Shavings" are not.

 

"Goo" would be a more accurate description. But it still looks excessive to me. I'll get to work on a catch can today.

 

I finally got around to installing the "foreman" catch can. I was suprised at the results. After 100 miles of hard driving, there may have been 1 tablespoon of oil in the can. BUT, I was low 1 quart.

So, I decided to do a test. I replaced my missing quart with Lucas Oil Stabilizer. Went down to the drag strip, and ran a 13.2 consistant with a best time of 13.1 @ 105 smoking all the whole time. The car weighed in at 3722, so I figure the times are about right with my mods (mac headers, slp lid, loudmouth). With the passes I made at the track, the stabilizer, and 200 hard miles, I've only burned about a quart (only a slight improvement).

In my searches, I've read that a tell tale sign of burnt rings, or blow-by is to drive the car, park, take the oil filler cap off and rev the engine. If smoke comes out of the oil filler neck, you have blow by. I did this and I do have a little smoke coming out the filler cap.

Is it possible to have bad valve seals and see smoke come out of the oil filler neck? Or is this something that only happens with burnt rings?

Here are a few other things I've noticed that might shed some light on the problem.

The car will burn about 1 quart every 300 miles if I just set the cruise at a resonable speed (65-70) and just cruise. I cannot see any visible smoke while cruising.

The car will consume 1 quart every 100 miles if i drive it like it's stolen. I feel bad for anyone that does steal this car, becuase the cops could just follow the smoke trail. Under WOT, the cloud is definatly white, but it is dark. This indicates to me that i'm burning slightly rich and butt loads of oil.

On a cold start up, the car ***** copious amounts of black soot on my drive way. I have 2 nice long streaks of black crap behind my parking spot. This usually clears up when the engine gets to temperature. Not to mention the piston slap is loud as all hell.

I have not performed a leak down test, and I'm not sure I intend to at this time. Early to mid fall, I plan to pull the motor and start my project. I don't have all the project details worked out yet, but it does include a complete re-build.

Is there anything I can do between now and the motor project to determine the severity of the problem and what it is without dumping lot's of money into it? In other words, is there any indications from reading the spark plugs, which cylinders are having a problem and what the problem might be? Is there an easy way to inpect the valve seals for leakage?

I don't want to get carried away trying to fix a problem that will be corrected when I'm doing my engine project, but at the same time, I would like to do something to make sure the car will be reliable and not smoke until the project starts.

 

Sounds like you may have spit a ring. My old 84' GMC w/built 350 did exactly what your describing. It consumed alot of oil, about what your using. I had more than usual metal on the dip stick, from the piston slapping around in the cylinder. And the loud as hell piston slap, well for me was the piston w/no rings slapping around. When i did a compression check 7 cylinders read 235-250. The #6 read 75. Just a little low.HEHEH. I wound up trashing the engine because when the ring went, it cut gashes in the cylinder wall pretty deep, the piston and cylinder head were dinged up bad.
I hope yours isnt that serious, but it sounds too familuar.

 

Not really sure if the rings are bad though. I think if I only had 7 cylinders I wouldn't beable to pull a 13.1 at the track. 1 cylinder is worth about 40 HP for the stock engine. Not sure. I really want to car to hold up until fall. It's not the daily driver, but I would like to drive it more often.

Thanks for the $.02. I'll keep it in mind.

 

I didnt feel much of a loss in power either. I even drove it from Austin to Galveston to have my dad look at it, and back to Austin to replace it.

Good luck though, hope its not that bad and will last.