HELP! P0307 + Burning Oil Consistently
06-27-2015, 07:26 PM
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HELP! P0307 + Burning Oil Consistently Noticed my car ('01 SS) was blowing blue smoke out of exhaust and had a slight miss so I hooked it up to a Tech II and got P0307
(#7 misfire). Initially I was thinking that the smoke had nothing to do with the misfire because i had noticed my PCV valve was leaking so I tried to track down the cause of the misfire individually. Swapped injectors, wires and coils but the #7 misfire is consistent. Now #2 has a slight misfire as well although significantly smaller according to the misfire data on the Tech II. Pulled the plug on #7 and it was completely fouled with carbon and oil. Installed new plugs (NGK Tr5 gapped to .060") but #7 and #2 are still misfiring.
On the PCV issue, I pulled the TB off and it along with my intake was SOAKED in oil. Also noticed that there is oil all over the firewall and there is oil leaking on the cylinder 7 header primary.
Someone please guide me into the right direction.
(#7 misfire). Initially I was thinking that the smoke had nothing to do with the misfire because i had noticed my PCV valve was leaking so I tried to track down the cause of the misfire individually. Swapped injectors, wires and coils but the #7 misfire is consistent. Now #2 has a slight misfire as well although significantly smaller according to the misfire data on the Tech II. Pulled the plug on #7 and it was completely fouled with carbon and oil. Installed new plugs (NGK Tr5 gapped to .060") but #7 and #2 are still misfiring.
On the PCV issue, I pulled the TB off and it along with my intake was SOAKED in oil. Also noticed that there is oil all over the firewall and there is oil leaking on the cylinder 7 header primary.
Someone please guide me into the right direction.
06-27-2015, 11:18 PM
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Long shot, but any chance the spark plug threads could be messed up on the number 7 cylinder?
Head gasket blown around that area?
VC cover gasket?
do you have a catch can on the car?
Bad ring on number 7?
Valve guide seal? But that wouldn't explain the oil on the header primary.
Just throwing out there what little I know.
Head gasket blown around that area?
VC cover gasket?
do you have a catch can on the car?
Bad ring on number 7?
Valve guide seal? But that wouldn't explain the oil on the header primary.
Just throwing out there what little I know.
06-28-2015, 08:48 PM
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Long shot, but any chance the spark plug threads could be messed up on the number 7 cylinder?
Head gasket blown around that area?
VC cover gasket?
do you have a catch can on the car?
Bad ring on number 7?
Valve guide seal? But that wouldn't explain the oil on the header primary.
Just throwing out there what little I know.
Head gasket blown around that area?
VC cover gasket?
do you have a catch can on the car?
Bad ring on number 7?
Valve guide seal? But that wouldn't explain the oil on the header primary.
Just throwing out there what little I know.
Valve cover gasket isn't damaged.
No catch can.
It is a pretty steady leak only when running. With the hood up and engine running the oil continues to hit the rear of #7 and burn off. Noticed some smoke also coming from my pcv valve hose to the left of the tb.
06-28-2015, 10:55 PM
#5
I would bet the PCV line behind the intake manifold is broken and excessive blow by is putting the oil on the firewall and #7 header tube. Can't think of any other way oil could get on the firewall. #7 is known for breaking ring lands so a borescope in the plug hole would be a good idea. You give no information on any mods so who knows what else it might be.
06-29-2015, 06:31 PM
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Only mods are long tubes. The car is pretty much stock. I pulled the intake off today to replace intake seals and I checked out the pcv hose assembly. It wasn't spraying oil on the firewall but where the pcv valve goes into the boot there was a vacuum leak so i sealed it up. Cleaned the intake manifold out and re-installed. Changed the #7 spark plug again and low and behold still misfire on #7. Wtf
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06-29-2015, 10:24 PM
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The fact that you say the plug was fouled out makes me think you have an issue with cylinder 7. A decent amount of oil in the intake is normal without a catch can. What did you find when you did your compression and leakdown test? I'm thinking you might have a broken ring or ring land.
07-01-2015, 06:58 PM
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So after running compression test, all cylinders were in the 160-180 range except, you guessed it, cylinder 7. It only was able to "get it up" to 25 psi.
Leak down test was performed afterwards and I had 90% leakage into the crankcase. I used a boroscope and took a peek inside number 7 and I didn't see the aftermath of a broken ring land so Im sure one or both of the compression rings took a s**t.
Looks like I will be pulling the engine and either rebuilding it or doing either a 370 or 408 build and re-installing with a bigger cam and some better heads. Only thing is I don't have a lift. I am a GM ASEP student and I work at a GM Dealership but I would not be able to use the lift at either of these facilities to drop the cradle.
On a side note, anyone in the Houston area know of any reputable machinists that specialize in ls engines that could do the machine work for my ss?
Leak down test was performed afterwards and I had 90% leakage into the crankcase. I used a boroscope and took a peek inside number 7 and I didn't see the aftermath of a broken ring land so Im sure one or both of the compression rings took a s**t.
Looks like I will be pulling the engine and either rebuilding it or doing either a 370 or 408 build and re-installing with a bigger cam and some better heads. Only thing is I don't have a lift. I am a GM ASEP student and I work at a GM Dealership but I would not be able to use the lift at either of these facilities to drop the cradle.
On a side note, anyone in the Houston area know of any reputable machinists that specialize in ls engines that could do the machine work for my ss?
07-01-2015, 07:01 PM
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The fact that you say the plug was fouled out makes me think you have an issue with cylinder 7. A decent amount of oil in the intake is normal without a catch can. What did you find when you did your compression and leakdown test? I'm thinking you might have a broken ring or ring land.
07-05-2015, 11:46 AM
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Anyone else have any recommendations?
07-06-2015, 01:56 PM
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I just need to decide on if I want to stroke my ls6 block to 383 or get an lq4/9 block and stroke to 402. I was leaning more towards the 383 because I already have the block and people are requesting a PREMIUM for lq blocks.