sl2 running like crap engine P0302 & PO405 codes

[DB42]

My car has been running pretty good, but it burns alot of oil and I have to check it everyday and put some in. well yesterday i checked it and maybe put in alittle to much cause soon after the engine light went on and was blinking also the car is running like its missing and hesitating. so I went to AZ for a scan and these codes came up. P0302 which is cylinder 2 & P0405 is EGR related i took the EGR off and cleaned it and put a new gasket on but no difference. I checked the spark plug tubes and no oil in them. help

[DB42]

I just put new plug wires on took off one by one so I know that there on right, but still runs rough and ses light blinking. I took plugs out and the 2nd one from passenger side had oil on it and I looked down the spark plug tube and could see oil on the valve the others were fine.

[BV22]

Blinking SES generally indicates a major misfire (in your case cylinder 2) which is allowing raw fuel into the cat. Suggest a compression test to see what is going on. Remove all plugs and the PCM B fuse before doing the test. Report results here. Sounds like something in cylinder 2 has given up.

[DB42]

I am going to try a new spark plug in cylinder 2 and try a used o2 sensor that I had laying around. also now the exhust is very loud. I dont know why? I am working this whole week so I have to use the car and I dont have time to do the compression check.

[madpogue]

You can't see the valves looking through the spark plug hole, unless you have a borescope. If you were seeing oil on the top of the piston, and it looked "fresh" (not "cooked"), there's probably a severe leak in one of the valve guide seals for that cylinder, letting in so much oil that it's not allowing the spark plug to fire. This would also explain the extreme oil consumption. Either that, or the oil ring on that piston is really shot.

For the EGR, you need to clean the passages in the head as well.

The codes coming up after the oil overfill was probably just a coincidence. Are you sure you didn't spill any oil on the valve cover, esp. the valley where the spark plug wires go in, when you added oil the last time? There was NO oil in the spark plug wells when you removed the wires, but before you removed the plugs?

[DB42]

Originally Posted by madpogue

You can't see the valves looking through the spark plug hole, unless you have a borescope. If you were seeing oil on the top of the piston, and it looked "fresh" (not "cooked"), there's probably a severe leak in one of the valve guide seals for that cylinder, letting in so much oil that it's not allowing the spark plug to fire. This would also explain the extreme oil consumption. Either that, or the oil ring on that piston is really shot.

For the EGR, you need to clean the passages in the head as well.

The codes coming up after the oil overfill was probably just a coincidence. Are you sure you didn't spill any oil on the valve cover, esp. the valley where the spark plug wires go in, when you added oil the last time? There was NO oil in the spark plug wells when you removed the wires, but before you removed the plugs?

there was only oil in cylinder 2 on top of the piston when i took that plug out it was wet looking not burnt. is there an easy way of fixing that? No I only maybe over filled about 1/4 to 1/2 qt and for sure didnt get any on the valve cover or in the valve cover valley.
Ok i just put a new plug in cylinder 2 and changed 02 sensor and put new pcv in and its still missing and low power and exhust sounds very loud and was never loud before this happened. exhust is in good shape.
would a new egr help? I just cleaned the pinnicle and the other big hole with carb cleaner and scraped carbon out. what is the head and how do i clean it?

[DB42]

why is the car so loud now?

[LabRat]

How is it loud? Exhaust loud? Did the replaced O2 sensor, spark plug or PCV get imcompletely tightened and perhaps blow back out?

-LR

[madpogue]

"Head" - the cylinder head of the engine. The EGR valve mounts on it. Remember when you removed it, you saw two holes in the head where it mounts? One of those is a passage to the intake manifold and the other is a passage to the exhaust manifold. Before replacing the EGR, try cleaning those two passages out. One quick-and-dirty method is to run the engine briefly with the EGR removed (if you think your car is loud now....)

Speaking of loud, it could be just about anything, but as usual, you should look at the most recent work you've done. The two things you've worked on that relate to the exhaust are the EGR and the oxygen sensor. If either one is not installed securely, that's an exhaust leak. See if you can pinpoint the source of the noise. Also feel around (be careful you don't burn yourself; the exhaust manifold gets HOT) those two installation points for leaking exhaust while the engine's running.

As for the #2, you could try blowing the oil out of it with compressed air, or just remove all the spark plugs, pull the PCM B fuse (so it doesn't feed fuel) and crank the engine several times with the starter. That might get the #2 chamber cleared enough of the oil to get it to fire again. But it will probably get sodden again fairly quickly, and the P0302 and flashing SES will return. This would only confirm that this is at the heart of your performance issue. You could try an MMO soak or two (or three) on that cylinder (may as well do all of them), to see if the oil consumption, and the oil buildup in that chamber, go down any. But that's a "Hail Mary"; at the apparent rate of consumption and corresponding oil buildup, it may not buy you much. But it's virtually free.

A compression test would also be worthwhile. It won't be conclusive, in that the oil rings and the valve guide seals both have no impact on compression. But it'll tell you about the general health of the engine, and if it turns out compression is low in that cylinder, it would indicate more significant damage/wear; a valve issue or scored cylinder wall.

Hmm, come to think of it, are you sure that's oil you're seeing in #2? If you can, remove all the spark plugs and turn the engine by hand until #2 is at top dead center, and try to extract some of what you're seeing. Turkey baster, or possibly even dipping a white paper towel in (be careful not to tear it). Give it a sniff as well. If, say, there's a burned or stuck valve, and that cylinder is not firing, that could be collected unburned fuel you're seeing.

[DB42]

Originally Posted by LabRat

How is it loud? Exhaust loud? Did the replaced O2 sensor, spark plug or PCV get imcompletely tightened and perhaps blow back out?

-LR

It was loud before i changed all the stuff.The exhaust just got loud like when theres no muffler attached. this all happend when the car started missing and hesitating and given me those codes. the exhust system looks good no rusted or holes in anything.

[DB42]

Originally Posted by madpogue

"Head" - the cylinder head of the engine. The EGR valve mounts on it. Remember when you removed it, you saw two holes in the head where it mounts? One of those is a passage to the intake manifold and the other is a passage to the exhaust manifold. Before replacing the EGR, try cleaning those two passages out. One quick-and-dirty method is to run the engine briefly with the EGR removed (if you think your car is loud now....)

Speaking of loud, it could be just about anything, but as usual, you should look at the most recent work you've done. The two things you've worked on that relate to the exhaust are the EGR and the oxygen sensor. If either one is not installed securely, that's an exhaust leak. See if you can pinpoint the source of the noise. Also feel around (be careful you don't burn yourself; the exhaust manifold gets HOT) those two installation points for leaking exhaust while the engine's running.

I did clean the egr head holes but i didnt start it to blow anything out before i put egr back on. the only spark plug that was fouled out with oil on it was #2 and when i look into #2 cylinder with flashlight after plug was out i could see wet oil and the other spark plugs were dry.

As for the #2, you could try blowing the oil out of it with compressed air, or just remove all the spark plugs, pull the PCM B fuse (so it doesn't feed fuel) and crank the engine several times with the starter. That might get the #2 chamber cleared enough of the oil to get it to fire again. But it will probably get sodden again fairly quickly, and the P0302 and flashing SES will return. This would only confirm that this is at the heart of your performance issue. You could try an MMO soak or two (or three) on that cylinder (may as well do all of them), to see if the oil consumption, and the oil buildup in that chamber, go down any. But that's a "Hail Mary"; at the apparent rate of consumption and corresponding oil buildup, it may not buy you much. But it's virtually free.

A compression test would also be worthwhile. It won't be conclusive, in that the oil rings and the valve guide seals both have no impact on compression. But it'll tell you about the general health of the engine, and if it turns out compression is low in that cylinder, it would indicate more significant damage/wear; a valve issue or scored cylinder wall.

Hmm, come to think of it, are you sure that's oil you're seeing in #2? If you can, remove all the spark plugs and turn the engine by hand until #2 is at top dead center, and try to extract some of what you're seeing. Turkey baster, or possibly even dipping a white paper towel in (be careful not to tear it). Give it a sniff as well. If, say, there's a burned or stuck valve, and that cylinder is not firing, that could be collected unburned fuel you're seeing.

Thank you for the help and info