Blue Smoke
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Blue Smoke Hi All, I hope someone can help!! Earlier this week I bought a car with an LS2 which was partially rebuilt. Invoice says: received new stem seals and notched recesses to provide clearance for rocker arms, new durabond cam bearings, replacement oil pump, grind crankshaft .010 on all journals. When I viewed the car there was a bit of black smoke from both exhausts which would indicate it was getting too much fuel. I got the car transported home so I only got a run out in it yesterday. After being out for a drive I gave it a few revs when I stopped to show someone the smoke (about 3,000 - 4,000 RPM) and it seemed reasonably clean following the drive. After idling for a minute I gave it a few revs and there was black smoke from the rights hand exhaust and blue smoke from the left, distinctively different colours. After a drive it seems to clear but after idle it returns... Has anyone had a similar problem or is there anything I can check? Thanks
Last edited by 20107847; Jun 21, 2020 at 04:14 AM.
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I'd start with a tune.
Black smoke means it's WAY rich. Too much of that will wash down the rings and allow oil past them.
Fix the rich problem, the other may well take care of itself. The longer it runs like that though, the more damage will end up being done to the bores, so don't wait.
Black smoke means it's WAY rich. Too much of that will wash down the rings and allow oil past them.
Fix the rich problem, the other may well take care of itself. The longer it runs like that though, the more damage will end up being done to the bores, so don't wait.
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That’s great thanks. There was a EFI Live Flashscan V2 came with the car. I understand the previous owner used this to set the car up himself and created the map. Would a standard LS2 map maybe fix the problem or am I better getting it professionally done? Thanks
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Get tuned first to resolve black smoke or you can wash rings and now you will need to tear the engine out for a minor hone to remove glaze. For oil, I'd check the PCV syste . Make sure it's working correctly and isnt clogged up or missing a restrictor. Then remove intake and look inside intake ports and look for oil. If the heads are ported or aftermarket, the Intake bolts will be exposed in the port and it will suck oil through those bolt . They need to be coated in high temp silicone. I'd start there and report back.
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Thanks everyone. I have contacted a local tuner to see if he can put the car on his rolling road and retune. In the mean time I removed the plugs and they seem to be a nice biscuit brown colour so maybe the car isn’t as rich as I thought?? When I had the plugs out I done a compression test on each cylinder and I’m getting 210 psi to 220 psi across the 8 cylinders. This was higher than I expected. Is this normal? Thanks
