HELP!!!! Cylinder 6 Spark plug covered with oil
06-23-18, 03:01 PM
#1
Driver
Thread Starter
HELP!!!! Miss fire, Spark plug oil, limp mode
Hello Guys,
A week a go I replaced all the Spark plugs. Cylinder 6 was slightly more blackish/oily than other plugs. yesterday i merged onto highway after work and suddenly the car started shuddering and I got CEL/VSC. I pulled over, Checked the code, Got P0306. I turned the car off and back on and the codes disappeared. The car however felt very underpowered. Got home and pulled the plug out and found it oily. There was also tiny bit of oil on the ignition coils. I checked all other spark plugs and they were fine. Just Cylinder 6 plug was oily. I have a video uploaded here:
There also seems to be a loss in power. Car does not pick up as it should and does not rev as high. It seems to struggle to go past 3k rpms. Feels like as if it lost some power. I did some research and things are pointing to bad Spark plug tube seals for that cylinder. The kit I'm looking at has valve cover gasket and tube seals included. https://www.thewrenchmonkey.ca/produ...-pro/vs50690r/
Can someone confirm I'm on the right track with diagnosis ?
07 IS250 140k kms. Ran like butter before I changed the plugs and this problem started happening.
Edit 1:
I researched the loss of power was due to car being in limp mode?. I Swapped plugs and boot from cylinder 6 to 4. I cleared all the codes and the car seemed to have gotten out of limp mode, smooth and high revving as before. After a a few test runs, the car went back into limp mode ( felt like it lost power, shifts werent as smooth) (last 2-4 mins of the datalog) and would hesitate to rev past 3k Rpm. I was logging the live data at the time so i have the Fuel trims captured.( Negative at idle and mostly staying in negatives). Check attachments. I checked my MAF it was clean as brand new. I will test again later with Techstream to see if any cylinders are miss firing. So far no codes. But I suspect the the miss fire and codes will return. The car revs high during idle but won't go past 3k when in gear.
Possible issues I'm thinking:
1. bad sparkplug tube seals
2. carbon buildup
3. compression problem ( i really hope not)
4. bad sparkplug/coils
Edit 2:
I've driven the car for the past 6 days and its been driving fine. I checked the boot for plug 6 today and it was perfect. No oil. I didnt check the sparkplug it self tho. My guess is the plug was loose. I'll update if anything happens.
A week a go I replaced all the Spark plugs. Cylinder 6 was slightly more blackish/oily than other plugs. yesterday i merged onto highway after work and suddenly the car started shuddering and I got CEL/VSC. I pulled over, Checked the code, Got P0306. I turned the car off and back on and the codes disappeared. The car however felt very underpowered. Got home and pulled the plug out and found it oily. There was also tiny bit of oil on the ignition coils. I checked all other spark plugs and they were fine. Just Cylinder 6 plug was oily. I have a video uploaded here:
There also seems to be a loss in power. Car does not pick up as it should and does not rev as high. It seems to struggle to go past 3k rpms. Feels like as if it lost some power. I did some research and things are pointing to bad Spark plug tube seals for that cylinder. The kit I'm looking at has valve cover gasket and tube seals included. https://www.thewrenchmonkey.ca/produ...-pro/vs50690r/
Can someone confirm I'm on the right track with diagnosis ?
07 IS250 140k kms. Ran like butter before I changed the plugs and this problem started happening.
Edit 1:
I researched the loss of power was due to car being in limp mode?. I Swapped plugs and boot from cylinder 6 to 4. I cleared all the codes and the car seemed to have gotten out of limp mode, smooth and high revving as before. After a a few test runs, the car went back into limp mode ( felt like it lost power, shifts werent as smooth) (last 2-4 mins of the datalog) and would hesitate to rev past 3k Rpm. I was logging the live data at the time so i have the Fuel trims captured.( Negative at idle and mostly staying in negatives). Check attachments. I checked my MAF it was clean as brand new. I will test again later with Techstream to see if any cylinders are miss firing. So far no codes. But I suspect the the miss fire and codes will return. The car revs high during idle but won't go past 3k when in gear.
Possible issues I'm thinking:
1. bad sparkplug tube seals
2. carbon buildup
3. compression problem ( i really hope not)
4. bad sparkplug/coils
Edit 2:
I've driven the car for the past 6 days and its been driving fine. I checked the boot for plug 6 today and it was perfect. No oil. I didnt check the sparkplug it self tho. My guess is the plug was loose. I'll update if anything happens.
Last edited by noblesenga; 06-29-18 at 11:02 AM. Reason: Changed Title
06-23-18, 03:21 PM
#2
Looks like what I have though just not as bad. Mine are cylinder 3, and 5. As of now I'm not sure sure where it's coming from. I'm thinking it's the lower tube seals on the head. If so it's going to cost me an arm and a leg. I pull the plugs once in awhile and clean it up. A few months back I had a slight miss while idling. The weird thing is the car ran like crap no CEL light. Once I cleaned everything off the car ran better for now.
Clean up where you can then monitor if it's leaking from the top well seals on the valve cover. You might want to get a new plug too.
Clean up where you can then monitor if it's leaking from the top well seals on the valve cover. You might want to get a new plug too.
The following users liked this post:
noblesenga (06-23-18)
06-24-18, 02:11 PM
#3
Driver
Thread Starter
Looks like what I have though just not as bad. Mine are cylinder 3, and 5. As of now I'm not sure sure where it's coming from. I'm thinking it's the lower tube seals on the head. If so it's going to cost me an arm and a leg. I pull the plugs once in awhile and clean it up. A few months back I had a slight miss while idling. The weird thing is the car ran like crap no CEL light. Once I cleaned everything off the car ran better for now.
Clean up where you can then monitor if it's leaking from the top well seals on the valve cover. You might want to get a new plug too.
Clean up where you can then monitor if it's leaking from the top well seals on the valve cover. You might want to get a new plug too.
06-24-18, 04:47 PM
#4
When you moved coil did the code follow it?
One observation is this; The plugs washer when sealed to the head will stop oil from going past the threads. The plug looks like it was swimming in oil. Clean oil is not conductive but that doesn't mean it won't cause a misfire.
If your engine burns oil, those threads could get that way from the combustion chamber. However, if its not an oil burner and the plug is properly tightened, the threads should remain clean.
Clean all the oil from the plug well.
Replace plugs that are saturated.
Tighten the plugs securely.
Monitor if the misfire follows the coil.
And sooner than later pull the coil from the oil filled plug well and see where the oil is coming from.
One observation is this; The plugs washer when sealed to the head will stop oil from going past the threads. The plug looks like it was swimming in oil. Clean oil is not conductive but that doesn't mean it won't cause a misfire.
If your engine burns oil, those threads could get that way from the combustion chamber. However, if its not an oil burner and the plug is properly tightened, the threads should remain clean.
Clean all the oil from the plug well.
Replace plugs that are saturated.
Tighten the plugs securely.
Monitor if the misfire follows the coil.
And sooner than later pull the coil from the oil filled plug well and see where the oil is coming from.
06-24-18, 05:44 PM
#5
Driver
Thread Starter
When you moved coil did the code follow it?
One observation is this; The plugs washer when sealed to the head will stop oil from going past the threads. The plug looks like it was swimming in oil. Clean oil is not conductive but that doesn't mean it won't cause a misfire.
If your engine burns oil, those threads could get that way from the combustion chamber. However, if its not an oil burner and the plug is properly tightened, the threads should remain clean.
Clean all the oil from the plug well.
Replace plugs that are saturated.
Tighten the plugs securely.
Monitor if the misfire follows the coil.
And sooner than later pull the coil from the oil filled plug well and see where the oil is coming from.
One observation is this; The plugs washer when sealed to the head will stop oil from going past the threads. The plug looks like it was swimming in oil. Clean oil is not conductive but that doesn't mean it won't cause a misfire.
If your engine burns oil, those threads could get that way from the combustion chamber. However, if its not an oil burner and the plug is properly tightened, the threads should remain clean.
Clean all the oil from the plug well.
Replace plugs that are saturated.
Tighten the plugs securely.
Monitor if the misfire follows the coil.
And sooner than later pull the coil from the oil filled plug well and see where the oil is coming from.
06-24-18, 09:42 PM
#6
Those two don't add up. A misfire is a misfire and the CEL comes on. This means it has a code NOT a pending code.
Limp mode is another beast to protect the engine and trans when valid inputs are not available and/or a command is given (like shift to 4th) but it can't determine if a shift to that gear occurred.
Misfire codes typically do not lead to "limp mode" where the trans had a single gear selected/available.
Perhaps clarify these details...
Limp mode is another beast to protect the engine and trans when valid inputs are not available and/or a command is given (like shift to 4th) but it can't determine if a shift to that gear occurred.
Misfire codes typically do not lead to "limp mode" where the trans had a single gear selected/available.
Perhaps clarify these details...
06-25-18, 05:09 AM
#7
Driver
Thread Starter
Those two don't add up. A misfire is a misfire and the CEL comes on. This means it has a code NOT a pending code.
Limp mode is another beast to protect the engine and trans when valid inputs are not available and/or a command is given (like shift to 4th) but it can't determine if a shift to that gear occurred.
Misfire codes typically do not lead to "limp mode" where the trans had a single gear selected/available.
Perhaps clarify these details...
Limp mode is another beast to protect the engine and trans when valid inputs are not available and/or a command is given (like shift to 4th) but it can't determine if a shift to that gear occurred.
Misfire codes typically do not lead to "limp mode" where the trans had a single gear selected/available.
Perhaps clarify these details...
based on my research, misfires CAN lead to limp mode. By limp mode I mean the car suddently feels like it lost power and struggles to rev past 3k rpms.
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06-25-18, 06:05 AM
#8
Think about this; at idle, lets say the engine is making 20hp between all six cylinders. Now if one hole is dead not only did you lose 3.3hp, but it just became an air compressor actually inducing a heavier load than if it wasn't there at all. Hence the loss of power and shaking.
The CEL being on in this case is not putting it in limp mode where it fixes the timing a set degree, runs the fuel trims at fixed amounts or takes off in 3rd gear and never shifts.
If it detects that the coil is unable to fire, it may disable the injectors on that hole to prevent fuel washing of the cylinder and preserve the CAT from being slugged with unburnt fuel.
Make sense?
The CEL being on in this case is not putting it in limp mode where it fixes the timing a set degree, runs the fuel trims at fixed amounts or takes off in 3rd gear and never shifts.
If it detects that the coil is unable to fire, it may disable the injectors on that hole to prevent fuel washing of the cylinder and preserve the CAT from being slugged with unburnt fuel.
Make sense?
06-25-18, 07:38 AM
#9
Driver
Thread Starter
Think about this; at idle, lets say the engine is making 20hp between all six cylinders. Now if one hole is dead not only did you lose 3.3hp, but it just became an air compressor actually inducing a heavier load than if it wasn't there at all. Hence the loss of power and shaking.
The CEL being on in this case is not putting it in limp mode where it fixes the timing a set degree, runs the fuel trims at fixed amounts or takes off in 3rd gear and never shifts.
If it detects that the coil is unable to fire, it may disable the injectors on that hole to prevent fuel washing of the cylinder and preserve the CAT from being slugged with unburnt fuel.
Make sense?
The CEL being on in this case is not putting it in limp mode where it fixes the timing a set degree, runs the fuel trims at fixed amounts or takes off in 3rd gear and never shifts.
If it detects that the coil is unable to fire, it may disable the injectors on that hole to prevent fuel washing of the cylinder and preserve the CAT from being slugged with unburnt fuel.
Make sense?
06-25-18, 07:47 AM
#10
To your point about limps modes and what I posted.
Limp modes occur when vital inputs are missing, like the two you mentioned. If the MAF is off line = limp as the ECM has no idea how much air is entering the engine. It runs with fail safe default fixed values.
The same with the TPS. If the values from these inputs are erroneous, the ECM goes to fail safe mode to protect the engine but hopefully get you to your destination without doing further damage to the engine.
Limp modes occur when vital inputs are missing, like the two you mentioned. If the MAF is off line = limp as the ECM has no idea how much air is entering the engine. It runs with fail safe default fixed values.
The same with the TPS. If the values from these inputs are erroneous, the ECM goes to fail safe mode to protect the engine but hopefully get you to your destination without doing further damage to the engine.
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noblesenga (06-25-18)
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