Impala Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
20 Posts
Discussion Starter #1
So I've been having oil consumption and now I have multiple misfires as well as afm or DoD won't activate so stuck in 8 cylinder mode...any experiences or idea?

Sent from my SM-N950U using Tapatalk
 

·
Registered
Joined
·
6 Posts
8 cylinder mode

So I've been having oil consumption and now I have multiple misfires as well as afm or DoD won't activate so stuck in 8 cylinder mode...any experiences or idea?

Sent from my SM-N950U using Tapatalk

Have you checked for any OBD codes? Many will stop the DoD to function. Also, check the oil pressure switch, if it is faulty, only 8 cylinder mode
 

·
Registered
Joined
·
20 Posts
Discussion Starter #3
Have you checked for any OBD codes? Many will stop the DoD to function. Also, check the oil pressure switch, if it is faulty, only 8 cylinder mode
Yes, p0300. Had mass air flow code, changed that. Cleared them and now just the one p0300

Sent from my SM-N950U using Tapatalk
 

·
Registered
Joined
·
1,089 Posts
Yes, p0300. Had mass air flow code, changed that. Cleared them and now just the one p0300

Sent from my SM-N950U using Tapatalk
That is a random misfire code. With burning oil and that code, would suspect head gasket or rings may be the problem. I am however not a mechanic, just do the vast majority of my own repairs. Would lean towards compression check to pinpoint which specific cylinders you are having the issues with.
 
  • Like
Reactions: domination2580

·
Registered
Joined
·
20 Posts
Discussion Starter #5
That is a random misfire code. With burning oil and that code, would suspect head gasket or rings may be the problem. I am however not a mechanic, just do the vast majority of my own repairs. Would lean towards compression check to pinpoint which specific cylinders you are having the issues with.
Well the plugs are pretty fouled up. Plan is to change plugs and wires and do compression checks while I'm doing that.

Sent from my SM-N950U using Tapatalk
 

·
Registered
Joined
·
20 Posts
Discussion Starter #6
Ok so, an update.....once again more misfire codes, I replaced the valve covers, and plugs, still burns oil. Is there a new oil pan gasket? What would cause my oil to be still dropping?

Sent from my SM-N950U using Tapatalk
 

·
Registered
Joined
·
2,974 Posts
Ok so, an update.....once again more misfire codes, I replaced the valve covers, and plugs, still burns oil. Is there a new oil pan gasket? What would cause my oil to be still dropping?
The LS4 motors have four cylinders which get shut down by the active fuel management system (AFM). I don't understand all the details, but the bottom sides of those four cylinders get sprayed with oil to keep them lubricated while shut down. Apparently, this oiling can result in some of the rings sticking which results in additional oil consumption.

The new gasket controls/reduces the amount of oil sprayed on the cylinders, to prevent the rings from sticking. But it does not unstick the rings. For that, there is a procedure that dealers can run which involves putting solvent in the cylinders to unstick the rings. I think they pour it down the spark plug holes and let it soak the rings for a while. Once the rings are freed, the oil consumption should go down.

HTH.

Doug

.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #8
The LS4 motors have four cylinders which get shut down by the active fuel management system (AFM). I don't understand all the details, but the bottom sides of those four cylinders get sprayed with oil to keep them lubricated while shut down. Apparently, this oiling can result in some of the rings sticking which results in additional oil consumption.



The new gasket controls/reduces the amount of oil sprayed on the cylinders, to prevent the rings from sticking. But it does not unstick the rings. For that, there is a procedure that dealers can run which involves putting solvent in the cylinders to unstick the rings. I think they pour it down the spark plug holes and let it soak the rings for a while. Once the rings are freed, the oil consumption should go down.



HTH.



Doug



.
I wonder if I absolutely need to do that procedure for cleaning the rings.... or if I can just do the oil pan gasket?

Sent from my SM-N950U using Tapatalk
 

·
Registered
Joined
·
2,974 Posts
I wonder if I absolutely need to do that procedure for cleaning the rings.... or if I can just do the oil pan gasket?
Like I said, the gasket won't unstick the rings. The oil consumption problem will still be there.

That said, the soaking procedure is easier than the gasket swap. Removing the oil pan is a pain. Removing plugs and pouring solvent isn't very hard. The key to that is knowing all the steps in the procedure. Does the piston need to be at TDC? What kind of solvent? How much? How long to soak? How to drain and re-fill/re-lube the engine to prevent damage? If you can figure out how to do all that, then go for it. For me, it was worth a few hundred dollars to let a pro do it.

HTH.

Doug

.
 

·
Registered
Joined
·
20 Posts
Discussion Starter #13
Well if this gasket doesn't fix most of the oil consumption issue, I'm going to be calling gm pretty heated. It was a bitch to get the tank out.


Sent from my SM-N950U using Tapatalk
 
1 - 14 of 14 Posts
Top