Well i bought this car a few months ago. It had 96miles on the "new" 6.0 iron block. As i go through the first 500 miles it smokes and burns oil. No problem right, it's probably just breaking in i told myself. Now after a little over 1k miles on the block it still does it. About 1qt oil a week and i only work 5miles away from home. There's no smoke when i'm driving but at idle after a while it will constantly smoke. Nasty oil smoke. The longer it idles it seems the worse it gets.

Does anyone have any suggestions? I don't believe it's the PCV system, i've checked the line and see a little oil residue but nothing abnormal. Should i do a compression check? I don't want it to blow up on me if it's just bad rings. I'd rather pull it down hone it and re-ring it.

Thanks,
-Dennis

 

What do the plugs look like?

 

I pulled cylinder 3 and 5 and they looked good. Maybe a little lean but no oil. I will pull the other 6 plugs tommarow when i get off of work.

 

Do a leak down test on all the cylinders for starters. Also, just describing it as "new" doesn't help much. You need to give a lot more details. If new means rebuilt, who rebuilt it and what kind of machine work and parts were used.

 

That's what i dont know. Sup it's rebuilt with stock internals arp rod bolts and arp head bolts. It's got the other stuff in the sig too. I can't even find out if it's a LQ4 or LQ9 block. It even looks like the deck has been shaved. I cant read the stamps on the front pass side. All i know is CSS did all the work to the car. Other than that i haven't been able to get any other info on the car.

 

I'd say try that first to check the rings.. Then look into valve seals. At higher R's it could be burning it off easier, but when it idles it could accumulate a little more. And yes, check the plugs to narrow it down to a certain cylinder(s).

 

Sounds like the rings didn't seat.

High RPM smoke is usually indicative of a PCV system problem. Since you're talking about low RPM, it's probably going to be the rings.

Don't use synthetic for the first 2000 or so miles of break-in on the LSx motor.
Check to see if the oil smells strongly of gasoline or has gasoline in it.

My 408 didn't smoke from Day 1 and still doesn't smoke with 2500 miles on the motor and running synthetic now.

Mike

 

I'm using just regular 10w30. I was going to change to synthetis around 2k but with it going through this much oil i don't see the point. I check the oil often and smell it but i dont smell a fuel residue.

So far does it sound like a pulldown in the near future?

 

Something's just not right. Do a compression/leakdown test and you'll have all of your answers.

 

One more thing to check is if the heads are ported , see if thread sealer was used on the intake rocker arm bolts . When the intake runners are ported the metal that is removed from the top of the runners exposes the intake rocker arm bolts to the intake charge, so if thread sealer was not used ,oil just simply runs down the threads and into the combustion chamber. Good luck!

 

I'm going to have to vote for rings as well...

 

this is what i found while pulling the plugs. This is the #2 cylinder.


I don't think that badboy was puttin out any sparks like that!! But seriously, that cylinder had 20psi more compression than the #3 cylinder which it's plugs looks outstanding. Those are the only 2 i have tested so far. Any coments?

 

hmmmm........
bad rings in that cylinder allowing oil into the combustion chamber, which will also coat the rings with oil and cause compression to go up

 

#2 looks like ****.

My guess is that you have a severe buildup on the piston (due to bad ring(s), making the compression higher on that cylinder.

You probably need to do a leakdown test to confirm your results.

 

Well i put a new plug in that cylinder and pulled it out again today. Had some buildup on it already. So i put another new one it it and gonna see how that does. But yea, i'm gonna pull it down and re-ring it and put new bearings in it. Hopefully when i pull it down i don't find something else wrong.