Burning oil constantly after something failed
11-05-2013, 01:53 PM
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Burning oil constantly after something failed
Hey everyone,
Something let go in my 03 AP1 and I am trying to approach this as informed as possible to prevent the garage being taken up any longer than it has to. Any input is greatly appreciated, so thank you in advance. Please speak from experience, not hearsay.
Background:
My 03 Ap1 is stock minus high flow cat and o2 bung spacer with 124k miles on the clock. I've owned it since 88k miles. When adjusting the valves, the head was extremely clean indicating regular maintenance. I change the oil every 2200 miles with Royal Purple 10w30 synthetic. Burning about a half a quart every 600-1000 miles depending on how much time I spend in the upper revs. I always monitor the oil level every two gas fill-ups, never letting it get low.
The other day while driving, I was accelerating wide open throttle 2nd through the top of 3rd. Let off after shifting into 4th then 5th. In 5th, heard a backfire and saw a cloud of smoke. Wasn't sure if the ECU hiccuped, but as I began to apply throttle again during cruise noticed that the car was smoking when I touched the gas. Shut the car off and had it towed home.
First thing I did was pull and inspect spark plugs. All looked OK. Cylinder 3 had a small amount of oil on the piston. I spun the motor by hand and it nothing seemed bound up. Performed a compression test. Got back 285 to 300 psi across the board. I know every gauge reads different and I never compression tested my S, but my Miata with 9:1 compression does 185-195 psi, and my Miata with 10:1 compression does 205-210 psi on this gauge. Assuming the F20c seals much better, just not sure by how much. Cylinder 3 with the oil did 300 psi, so I think some of that number was a result of the oil in there.
I put the plugs back in a started the car. The engine sounds fine and the motor revs smoothly. However, it is consistently smoking, even at idle, and it smells of burnt oil. Revving the engine creates more smoke.
Now, based on this information I think either a valve guide is worn, a valve seal has failed, or possible a piston ringland may have chunked off. I have seen ringlands on the older B-series chunk off, but not sure if the F series have this issue with their forged pistons. I was going to remove the intake manifold and exhaust manifold to see if there is oil on the backside of the valves? Is it even possible for oil to get onto the back of the valve if the seal is good but the guide is worn? Is there anything else that can be done to diagnose or pin point where the issue is before taking it apart and making the car immobile? Would a failed valve seal be visible with the cams in place? Other than wiggling a valve with the head removed and keeper unlocked is there another way to diagnose a worn valve guide?
I am just debating if I should buy new valve seals now or even a spare head before I take this apart. Again, with winter approaching I am trying to avoid having the car stuck in the garage. Anything else that I should consider purchasing ahead of time or be ready to replace after removing the head, please let me know.
Thanks again in advance,
Quinn
Something let go in my 03 AP1 and I am trying to approach this as informed as possible to prevent the garage being taken up any longer than it has to. Any input is greatly appreciated, so thank you in advance. Please speak from experience, not hearsay.
Background:
My 03 Ap1 is stock minus high flow cat and o2 bung spacer with 124k miles on the clock. I've owned it since 88k miles. When adjusting the valves, the head was extremely clean indicating regular maintenance. I change the oil every 2200 miles with Royal Purple 10w30 synthetic. Burning about a half a quart every 600-1000 miles depending on how much time I spend in the upper revs. I always monitor the oil level every two gas fill-ups, never letting it get low.
The other day while driving, I was accelerating wide open throttle 2nd through the top of 3rd. Let off after shifting into 4th then 5th. In 5th, heard a backfire and saw a cloud of smoke. Wasn't sure if the ECU hiccuped, but as I began to apply throttle again during cruise noticed that the car was smoking when I touched the gas. Shut the car off and had it towed home.
First thing I did was pull and inspect spark plugs. All looked OK. Cylinder 3 had a small amount of oil on the piston. I spun the motor by hand and it nothing seemed bound up. Performed a compression test. Got back 285 to 300 psi across the board. I know every gauge reads different and I never compression tested my S, but my Miata with 9:1 compression does 185-195 psi, and my Miata with 10:1 compression does 205-210 psi on this gauge. Assuming the F20c seals much better, just not sure by how much. Cylinder 3 with the oil did 300 psi, so I think some of that number was a result of the oil in there.
I put the plugs back in a started the car. The engine sounds fine and the motor revs smoothly. However, it is consistently smoking, even at idle, and it smells of burnt oil. Revving the engine creates more smoke.
Now, based on this information I think either a valve guide is worn, a valve seal has failed, or possible a piston ringland may have chunked off. I have seen ringlands on the older B-series chunk off, but not sure if the F series have this issue with their forged pistons. I was going to remove the intake manifold and exhaust manifold to see if there is oil on the backside of the valves? Is it even possible for oil to get onto the back of the valve if the seal is good but the guide is worn? Is there anything else that can be done to diagnose or pin point where the issue is before taking it apart and making the car immobile? Would a failed valve seal be visible with the cams in place? Other than wiggling a valve with the head removed and keeper unlocked is there another way to diagnose a worn valve guide?
I am just debating if I should buy new valve seals now or even a spare head before I take this apart. Again, with winter approaching I am trying to avoid having the car stuck in the garage. Anything else that I should consider purchasing ahead of time or be ready to replace after removing the head, please let me know.
Thanks again in advance,
Quinn
11-05-2013, 06:13 PM
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Hey everyone,
Something let go in my 03 AP1 and I am trying to approach this as informed as possible to prevent the garage being taken up any longer than it has to. Any input is greatly appreciated, so thank you in advance. Please speak from experience, not hearsay.
Background:
My 03 Ap1 is stock minus high flow cat and o2 bung spacer with 124k miles on the clock. I've owned it since 88k miles. When adjusting the valves, the head was extremely clean indicating regular maintenance. I change the oil every 2200 miles with Royal Purple 10w30 synthetic. Burning about a half a quart every 600-1000 miles depending on how much time I spend in the upper revs. I always monitor the oil level every two gas fill-ups, never letting it get low.
The other day while driving, I was accelerating wide open throttle 2nd through the top of 3rd. Let off after shifting into 4th then 5th. In 5th, heard a backfire and saw a cloud of smoke. Wasn't sure if the ECU hiccuped, but as I began to apply throttle again during cruise noticed that the car was smoking when I touched the gas. Shut the car off and had it towed home.
First thing I did was pull and inspect spark plugs. All looked OK. Cylinder 3 had a small amount of oil on the piston. I spun the motor by hand and it nothing seemed bound up. Performed a compression test. Got back 285 to 300 psi across the board. I know every gauge reads different and I never compression tested my S, but my Miata with 9:1 compression does 185-195 psi, and my Miata with 10:1 compression does 205-210 psi on this gauge. Assuming the F20c seals much better, just not sure by how much. Cylinder 3 with the oil did 300 psi, so I think some of that number was a result of the oil in there.
I put the plugs back in a started the car. The engine sounds fine and the motor revs smoothly. However, it is consistently smoking, even at idle, and it smells of burnt oil. Revving the engine creates more smoke.
Now, based on this information I think either a valve guide is worn, a valve seal has failed, or possible a piston ringland may have chunked off. I have seen ringlands on the older B-series chunk off, but not sure if the F series have this issue with their forged pistons. I was going to remove the intake manifold and exhaust manifold to see if there is oil on the backside of the valves? Is it even possible for oil to get onto the back of the valve if the seal is good but the guide is worn? Is there anything else that can be done to diagnose or pin point where the issue is before taking it apart and making the car immobile? Would a failed valve seal be visible with the cams in place? Other than wiggling a valve with the head removed and keeper unlocked is there another way to diagnose a worn valve guide?
I am just debating if I should buy new valve seals now or even a spare head before I take this apart. Again, with winter approaching I am trying to avoid having the car stuck in the garage. Anything else that I should consider purchasing ahead of time or be ready to replace after removing the head, please let me know.
Thanks again in advance,
Quinn
Something let go in my 03 AP1 and I am trying to approach this as informed as possible to prevent the garage being taken up any longer than it has to. Any input is greatly appreciated, so thank you in advance. Please speak from experience, not hearsay.
Background:
My 03 Ap1 is stock minus high flow cat and o2 bung spacer with 124k miles on the clock. I've owned it since 88k miles. When adjusting the valves, the head was extremely clean indicating regular maintenance. I change the oil every 2200 miles with Royal Purple 10w30 synthetic. Burning about a half a quart every 600-1000 miles depending on how much time I spend in the upper revs. I always monitor the oil level every two gas fill-ups, never letting it get low.
The other day while driving, I was accelerating wide open throttle 2nd through the top of 3rd. Let off after shifting into 4th then 5th. In 5th, heard a backfire and saw a cloud of smoke. Wasn't sure if the ECU hiccuped, but as I began to apply throttle again during cruise noticed that the car was smoking when I touched the gas. Shut the car off and had it towed home.
First thing I did was pull and inspect spark plugs. All looked OK. Cylinder 3 had a small amount of oil on the piston. I spun the motor by hand and it nothing seemed bound up. Performed a compression test. Got back 285 to 300 psi across the board. I know every gauge reads different and I never compression tested my S, but my Miata with 9:1 compression does 185-195 psi, and my Miata with 10:1 compression does 205-210 psi on this gauge. Assuming the F20c seals much better, just not sure by how much. Cylinder 3 with the oil did 300 psi, so I think some of that number was a result of the oil in there.
I put the plugs back in a started the car. The engine sounds fine and the motor revs smoothly. However, it is consistently smoking, even at idle, and it smells of burnt oil. Revving the engine creates more smoke.
Now, based on this information I think either a valve guide is worn, a valve seal has failed, or possible a piston ringland may have chunked off. I have seen ringlands on the older B-series chunk off, but not sure if the F series have this issue with their forged pistons. I was going to remove the intake manifold and exhaust manifold to see if there is oil on the backside of the valves? Is it even possible for oil to get onto the back of the valve if the seal is good but the guide is worn? Is there anything else that can be done to diagnose or pin point where the issue is before taking it apart and making the car immobile? Would a failed valve seal be visible with the cams in place? Other than wiggling a valve with the head removed and keeper unlocked is there another way to diagnose a worn valve guide?
I am just debating if I should buy new valve seals now or even a spare head before I take this apart. Again, with winter approaching I am trying to avoid having the car stuck in the garage. Anything else that I should consider purchasing ahead of time or be ready to replace after removing the head, please let me know.
Thanks again in advance,
Quinn
11-06-2013, 05:29 AM
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^^ +1 on the retainers as well.
The last valve adjustment was roughly 10k miles. What happens if the retainer cracks? Does the valve just drop down and get smashed? Wouldn't something like that be more obvious?
11-06-2013, 07:42 AM
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I could be wrong but even my fresh rebuit f20 didnt even see compression numbers like that... seems a little off to me .... plus 1 on the retainers as well and I have a spoon head and gasket
11-06-2013, 07:45 AM
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Wouldn't scratched cylinder walls, bad valve seals or bent valves show on the comp test?? And agreed, those numbers are really high, but consistency is key I guess.
There are a couple of good write-ups on cracked AP1 retainers in this forum's stickie section. They'll tell you what to look for in that department.
I'm assuming no dtc's?
No noise from the motor?
Any noise from the hfc area?
How bad is the smoking, got a video maybe?
There are a couple of good write-ups on cracked AP1 retainers in this forum's stickie section. They'll tell you what to look for in that department.
I'm assuming no dtc's?
No noise from the motor?
Any noise from the hfc area?
How bad is the smoking, got a video maybe?
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11-06-2013, 07:46 AM
#8
I think you blew out the piston rings which explains why you got oil in the cylinders. Typically the compression goes up when you squirt oil into the cylinder coz oil fill small gaps/holes on the piston rings. Also because everytime you rev it smokes, oil is getting past the pistons rings (if there is any left) and making it's way into the combustion chamber and getting burned up. If the engine idles fine then it's probably not your retainers, and bad retainers don't typically make any noise unless they are severely cracked in which case you would hear a fast clicking sound. Also you would be getting mis fires if it dropped a valve and it would be idling like a Subaru. Start looking for a new engine or rebuild the current one
Haven't seen or heard this on the s2k before must be coz of that purple oil crap....
Haven't seen or heard this on the s2k before must be coz of that purple oil crap....
11-06-2013, 07:58 AM
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11-06-2013, 08:06 AM
#10
Royal Purple has nothing to do with it....
I have buddies that run it religiously in their track cars and have for the past 60+K miles with zero burning issues. All oil has to meet standards and RP far exceeds the standards of the shittiest of oils on the shelf.
I have buddies that run it religiously in their track cars and have for the past 60+K miles with zero burning issues. All oil has to meet standards and RP far exceeds the standards of the shittiest of oils on the shelf.