Who has had a successful resolution to the oil burning issue or ticking issue
12-08-2011, 11:48 PM
#41
JK Super Freak
I have never had start-up knock, significant valvetrain noise, or any other symptoms that would lead me to suspect I had an oiling system issue until relatively recently, when my oil consumption suddenly climbed at just before 40K miles. This rang alarm bells for me as 40K miles appears to be the precise mileage that a lot of these motors suddenly increase oil consumption and spin bearings, and as my warranty is up at the end of this month I began researching here and elsewhere, did some experimentation, and came up with some findings. Here is briefly what I came up with (I have put all the oil specs in bold to make it clear which ones I am talking about in a given sentence):
Symptoms and diagnostics:
*The motor in my 9/'08 build JK never consumed oil with the dealer fill in it (10W30 Castrol Halvoline dino is what they use where I am) however would use a little (half a quart or less per 3-4K miles) on the 5W30 Castrol Edge full synthetic I put in for my in-between scheduled service oil changes.
*Suddenly, around 36K miles, consumption rose to over a quart in 2K miles on the 5W30 so I began my investigations. The incidence of detonation (pinging) also increased dramatically at this time, suggesting carbon build-up from burnt oil in the combustion chamber.
*Ran a compression test; all good however the plugs did have a lot of carbon on them.
*Removed the PVC valve to check it; valve was gummed up & I suspect not operating correctly (didn't cut it open to see inside) and the tubing to the intake was full of oil (so I suspect the intake & throttle body is caked in it too; will check these when I get time)
*Installed a new PCV valve, topped up crankcase, and the motor used no more oil for the remaining 2K miles until dealer service.
My conclusions are the following:
*these motors were originally engineered by Chrysler to run on 10W30. Chrysler revised this down to 5W30 and then again to 5W20 (with the introduction of the JK) over the years purely for mileage reasons.
*No significant changes were made to tolerances, pistons/rings or the design of the PCV system to account for the switch to this thinner oil specification, so these motors will consume more oil than they previously did in their minivan applications, both as blow-by past the rings and by the intake, via the PCV system. This thinner oil, combined with the drastic reduction in levels of the anti-wear additive zinc and phosphorus in the latest "anti-pollution" API certified oils (zinc & phosphorus are very good at minimising engine wear but they reduce the life of cat converters, so it was decided they had to go) has resulted in nosier running 3.8L motors that wear more quickly and consume excessive amounts of oil; the fact that lead has been removed from the bearing alloy (again for pollution reasons as lead also kills the cats) making them lighter-duty just compounds the problem. People will often respond to the above with "but modern fully-synthetic oils have a much stronger film strength compared to dino & thus can be thinner and do without high amounts of anti-wear additives"; all true, however Chrysler does not specify that synthetic must be used and most dealers and owners use regular dino, as full-synthetic is very expensive in comparison.
*At my next oil change (when I won't have to worry about warranty anymore; only reason I use 5W30 now) I will switch to a 10 or 15W40 weight oil of a superceeded API specification that is high in anti-wear additives; I live in a hot climate so I don't need a thin 5 or even 10 winter rating anyway, but do need a higher hot-temperature viscosity number like 40. I anticipate that this will drastically reduce my oil consumption, and even if it reduces my mileage by 1or 2 MPG I still come out ahead as my motor wll last a lot longer and have fewer maintainance issues. Most motors of the 3.8L's design (iron block, pushrod, low output 60-degree V6) where I am (like the legendary GM 3.8L for example) have 15W40 as their specified fill.
*I also intend to fit a catch-can to the PVC line to further minimise the amount of oil entering the intake. A member here fitted a catch-can to his 3.8L's PCV line (with a clear sightglass so the oil level could be clearly seen in the pictures he provided) and captured several fluid ounces of 5W20 in it in a little over a week.
Anyway, hope this has been of some help.
Symptoms and diagnostics:
*The motor in my 9/'08 build JK never consumed oil with the dealer fill in it (10W30 Castrol Halvoline dino is what they use where I am) however would use a little (half a quart or less per 3-4K miles) on the 5W30 Castrol Edge full synthetic I put in for my in-between scheduled service oil changes.
*Suddenly, around 36K miles, consumption rose to over a quart in 2K miles on the 5W30 so I began my investigations. The incidence of detonation (pinging) also increased dramatically at this time, suggesting carbon build-up from burnt oil in the combustion chamber.
*Ran a compression test; all good however the plugs did have a lot of carbon on them.
*Removed the PVC valve to check it; valve was gummed up & I suspect not operating correctly (didn't cut it open to see inside) and the tubing to the intake was full of oil (so I suspect the intake & throttle body is caked in it too; will check these when I get time)
*Installed a new PCV valve, topped up crankcase, and the motor used no more oil for the remaining 2K miles until dealer service.
My conclusions are the following:
*these motors were originally engineered by Chrysler to run on 10W30. Chrysler revised this down to 5W30 and then again to 5W20 (with the introduction of the JK) over the years purely for mileage reasons.
*No significant changes were made to tolerances, pistons/rings or the design of the PCV system to account for the switch to this thinner oil specification, so these motors will consume more oil than they previously did in their minivan applications, both as blow-by past the rings and by the intake, via the PCV system. This thinner oil, combined with the drastic reduction in levels of the anti-wear additive zinc and phosphorus in the latest "anti-pollution" API certified oils (zinc & phosphorus are very good at minimising engine wear but they reduce the life of cat converters, so it was decided they had to go) has resulted in nosier running 3.8L motors that wear more quickly and consume excessive amounts of oil; the fact that lead has been removed from the bearing alloy (again for pollution reasons as lead also kills the cats) making them lighter-duty just compounds the problem. People will often respond to the above with "but modern fully-synthetic oils have a much stronger film strength compared to dino & thus can be thinner and do without high amounts of anti-wear additives"; all true, however Chrysler does not specify that synthetic must be used and most dealers and owners use regular dino, as full-synthetic is very expensive in comparison.
*At my next oil change (when I won't have to worry about warranty anymore; only reason I use 5W30 now) I will switch to a 10 or 15W40 weight oil of a superceeded API specification that is high in anti-wear additives; I live in a hot climate so I don't need a thin 5 or even 10 winter rating anyway, but do need a higher hot-temperature viscosity number like 40. I anticipate that this will drastically reduce my oil consumption, and even if it reduces my mileage by 1or 2 MPG I still come out ahead as my motor wll last a lot longer and have fewer maintainance issues. Most motors of the 3.8L's design (iron block, pushrod, low output 60-degree V6) where I am (like the legendary GM 3.8L for example) have 15W40 as their specified fill.
*I also intend to fit a catch-can to the PVC line to further minimise the amount of oil entering the intake. A member here fitted a catch-can to his 3.8L's PCV line (with a clear sightglass so the oil level could be clearly seen in the pictures he provided) and captured several fluid ounces of 5W20 in it in a little over a week.
Anyway, hope this has been of some help.
Last edited by JKlad; 12-10-2011 at 09:16 PM. Reason: Updated information, corrected some "facts"
12-09-2011, 03:52 AM
#42
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Originally Posted by JKlad
I have never had start-up knock, significant valetrain noise, or any other symptoms that would lead me to suspect I had an oiling system issue until relatively recently, when my oil consumption suddenly climbed at just before 40K miles. This rang alarm bells for me as 40K miles appears to be the precise mileage that a lot of these motors suddenly increase oil consumption and spin bearings, and as my warranty is up at the end of this month I began researching here and elsewhere, did some experimentation, and came up with some findings. Here is briefly what I came up with (I have put all the oil specs in bold to make it clear which ones I am talking about in a given sentence):
Symptoms and diagnostics:
*The motor in my 9/'08 build JK never consumed oil with the dealer fill in it (10W30 Castrol Halvoline dino is what they use where I am) however would use a little (half a quart or less per 3-4K miles) on the 5W30 Castrol Edge full synthetic I put in for my in-between scheduled service oil changes.
*Suddenly, around 36K miles, consumption rose to over a quart in 2K miles on the 5W30 so I began my investigations. The incidence of detonation (pinging) also increased dramatically at this time, suggesting carbon build-up from burnt oil in the combustion chamber.
*Ran a compression test; all good however the plugs did have a lot of carbon on them.
*Removed the PVC valve to check it; valve was gummed up & I suspect not operating correctly (didn't cut it open to see inside) and the tubing to the intake was full of oil (so I suspect the intake & throttle body is caked in it too; will check these when I get time)
*Installed a new PCV valve, topped up crankcase, and the motor used no more oil for the remaining 2K miles until dealer service.
My conclusions are the following:
*these motors were originally engineered by Chrysler to run on 10W30. Chrysler revised this down to 5W30 and then again to 5W20 (with the introduction of the JK) over the years purely for mileage reasons.
*No significant changes were made to tolerances, pistons/rings or the design of the PCV system to account for the switch to this thinner oil specification, so these motors will consume more oil than they previously did in their minivan applications, both as blow-by past the rings and by the intake, via the PCV system. This thinner oil, combined with the drastic reduction in levels of the anti-wear additive zinc and phosphorus in the latest "anti-pollution" API certified oils (zinc & phosphorus are very good at minimising engine wear but they reduce the life of cat converters, so it was decided they had to go) has resulted in nosier running 3.8L motors that wear more quickly and consume excessive amounts of oil; the fact that lead has been removed from the bearing alloy (again for pollution reasons as lead also kills the cats) making them lighter-duty just compounds the problem. People will often respond to the above with "but modern fully-synthetic oils have a much stronger film strength compared to dino & thus can be thinner and do without high amounts of anti-wear additives"; all true, however Chrysler does not specify that synthetic must be used and most dealers and owners use regular dino, as full-synthetic is very expensive in comparison.
*At my next oil change (when I won't have to worry about warranty anymore; only reason I use 5W30 now) I will switch to a 10 or 15W40 weight oil of a superceeded API specification that is high in anti-wear additives; I live in a hot climate so I don't need a thin 5 or even 10 winter rating anyway, but do need a higher hot-temperature viscosity number like 40. I anticipate that this will drastically reduce my oil consumption, and even if it reduces my mileage by 1or 2 MPG I still come out ahead as my motor wll last a lot longer and have fewer maintainance issues. Most motors of the 3.8L's design (iron block, pushrod, low output 60-degree V6) where I am (like the legendary GM 3.8L for example) have 15W40 as their specified fill.
*I also intend to fit a catch-can to the PVC line to further minimise the amount of oil entering the intake. On previous vehicles I've owned in the past, the PCV line from the rocker cover ran to the outside of the air cleaner and had a sponge attached (which you removed and cleaned/replaced periodically) which would filter out most of the oil coming up the line, with the rest being captured by the air filter itself (oil could be clearly seen on the outside surface of the filter media at the precise spot where the sponge-capped PCV line sat against the filter, but not on the inside surface meaning the filter was doing it's job of keeping contaminants out of the intake. Also, these motors ran thick 'ole 25W50 meaning there wouldn't be as much vaporised oil getting up the line & needing to be filtered out in the first place). On the JK's 3.8L however the PVC line runs straight from the PCV valve directly into the upper intake manifold, bypassing the air filter entirely. A member here fitted a catch-can to his 3.8L's PCV line (with a clear sightglass so the oil level could be clearly seen in the pictures he provided) and captured several fluid ounces of 5W20 in it in a little over a week.
Anyway, hope this has been of some help.
Symptoms and diagnostics:
*The motor in my 9/'08 build JK never consumed oil with the dealer fill in it (10W30 Castrol Halvoline dino is what they use where I am) however would use a little (half a quart or less per 3-4K miles) on the 5W30 Castrol Edge full synthetic I put in for my in-between scheduled service oil changes.
*Suddenly, around 36K miles, consumption rose to over a quart in 2K miles on the 5W30 so I began my investigations. The incidence of detonation (pinging) also increased dramatically at this time, suggesting carbon build-up from burnt oil in the combustion chamber.
*Ran a compression test; all good however the plugs did have a lot of carbon on them.
*Removed the PVC valve to check it; valve was gummed up & I suspect not operating correctly (didn't cut it open to see inside) and the tubing to the intake was full of oil (so I suspect the intake & throttle body is caked in it too; will check these when I get time)
*Installed a new PCV valve, topped up crankcase, and the motor used no more oil for the remaining 2K miles until dealer service.
My conclusions are the following:
*these motors were originally engineered by Chrysler to run on 10W30. Chrysler revised this down to 5W30 and then again to 5W20 (with the introduction of the JK) over the years purely for mileage reasons.
*No significant changes were made to tolerances, pistons/rings or the design of the PCV system to account for the switch to this thinner oil specification, so these motors will consume more oil than they previously did in their minivan applications, both as blow-by past the rings and by the intake, via the PCV system. This thinner oil, combined with the drastic reduction in levels of the anti-wear additive zinc and phosphorus in the latest "anti-pollution" API certified oils (zinc & phosphorus are very good at minimising engine wear but they reduce the life of cat converters, so it was decided they had to go) has resulted in nosier running 3.8L motors that wear more quickly and consume excessive amounts of oil; the fact that lead has been removed from the bearing alloy (again for pollution reasons as lead also kills the cats) making them lighter-duty just compounds the problem. People will often respond to the above with "but modern fully-synthetic oils have a much stronger film strength compared to dino & thus can be thinner and do without high amounts of anti-wear additives"; all true, however Chrysler does not specify that synthetic must be used and most dealers and owners use regular dino, as full-synthetic is very expensive in comparison.
*At my next oil change (when I won't have to worry about warranty anymore; only reason I use 5W30 now) I will switch to a 10 or 15W40 weight oil of a superceeded API specification that is high in anti-wear additives; I live in a hot climate so I don't need a thin 5 or even 10 winter rating anyway, but do need a higher hot-temperature viscosity number like 40. I anticipate that this will drastically reduce my oil consumption, and even if it reduces my mileage by 1or 2 MPG I still come out ahead as my motor wll last a lot longer and have fewer maintainance issues. Most motors of the 3.8L's design (iron block, pushrod, low output 60-degree V6) where I am (like the legendary GM 3.8L for example) have 15W40 as their specified fill.
*I also intend to fit a catch-can to the PVC line to further minimise the amount of oil entering the intake. On previous vehicles I've owned in the past, the PCV line from the rocker cover ran to the outside of the air cleaner and had a sponge attached (which you removed and cleaned/replaced periodically) which would filter out most of the oil coming up the line, with the rest being captured by the air filter itself (oil could be clearly seen on the outside surface of the filter media at the precise spot where the sponge-capped PCV line sat against the filter, but not on the inside surface meaning the filter was doing it's job of keeping contaminants out of the intake. Also, these motors ran thick 'ole 25W50 meaning there wouldn't be as much vaporised oil getting up the line & needing to be filtered out in the first place). On the JK's 3.8L however the PVC line runs straight from the PCV valve directly into the upper intake manifold, bypassing the air filter entirely. A member here fitted a catch-can to his 3.8L's PCV line (with a clear sightglass so the oil level could be clearly seen in the pictures he provided) and captured several fluid ounces of 5W20 in it in a little over a week.
Anyway, hope this has been of some help.
12-09-2011, 05:46 AM
#43
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Also, my last Royal Purple sample had 6000 miles on it and over 50% of the additive package left and little loss in viscosity. Aside from the copper in the oil (perhaps solveable with a bypass filter), there would be no reason to change the oil.
12-09-2011, 05:55 AM
#44
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Originally Posted by Dronac
I'v been running 5w-30 since my short block was replaced under warranty (spun bearing) and have oil analysis' done to every oil change. So far my numbers have been good, although copper is pretty high. Every JK 3.8 oil analysis I'v seen shows high copper levels. So far, Royal Purple has Mobil Clean 5000 beat in wear numbers in my engine. I want to give 5w-20 another shot so my next fill will be regular dino 5w-20. If the wear goes up, then I'll try going a short run of oil thicker then 5w-30.
Also, my last Royal Purple sample had 6000 miles on it and over 50% of the additive package left and little loss in viscosity. Aside from the copper in the oil (perhaps solveable with a bypass filter), there would be no reason to change the oil.
12-09-2011, 06:57 AM
#45
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Fixed engine knock but oil consumption is very high. Been running mobile 1 synthetic for the last 30k miles, tried 3 or 4 different filters. Mobiles work the best. Knock disappeared. Stay away from the mopar filters.
The oil consumption is a problem. Burn about 3 quarts every 3k oil change using mobile 1 5w20 synthetic oil. Motor still runs fantastic at 50k miles, and i drive the engine hard. Will make the switch to 5w30 soon to test difference.
The oil consumption is a problem. Burn about 3 quarts every 3k oil change using mobile 1 5w20 synthetic oil. Motor still runs fantastic at 50k miles, and i drive the engine hard. Will make the switch to 5w30 soon to test difference.
Many engines will "burn off" oil until it reaches a certain volume. Lets just say that the 3.8L motor is "happy" with 4.35 quarts in it. Every ounce over this amount will be burned off. 4.35 is the Default oil level. So, if you're checking your oil level & it is down .5 quarts, naturally you put in a half a quart, when actually you should leave it alone. My guess is it will take much longer for it to burn the next half a quart.
Mine: 07 X, Castrol GTX 5-20, change every 3K, 85 octane gas, no burning, ticking, knocking. Certainly don't drive it like I stole it.
12-09-2011, 09:16 AM
#46
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It hasn't consumed any even before I spun a bearing. I only ran one fill of 5w-20 after the short block replacement and didn't see any consumption. The engine does sound noticably quieter with 5w-30 though. Heck, I think my front crankshaft seal is leaking and I STILL don't have any noticeable oil loss after 3k miles on this current oil fill.
Last edited by Dronac; 12-09-2011 at 09:22 AM.
12-09-2011, 11:00 AM
#47
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Originally Posted by Dronac
It hasn't consumed any even before I spun a bearing. I only ran one fill of 5w-20 after the short block replacement and didn't see any consumption. The engine does sound noticably quieter with 5w-30 though. Heck, I think my front crankshaft seal is leaking and I STILL don't have any noticeable oil loss after 3k miles on this current oil fill.
12-09-2011, 12:25 PM
#48
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Great thread, I will follow this closely as I'm burning around 4 qts/change.
"*I also intend to fit a catch-can to the PVC line to further minimise the amount of oil entering the intake. On previous vehicles I've owned in the past, the PCV line from the rocker cover ran to the outside of the air cleaner and had a sponge attached (which you removed and cleaned/replaced periodically) which would filter out most of the oil coming up the line, with the rest being captured by the air filter itself (oil could be clearly seen on the outside surface of the filter media at the precise spot where the sponge-capped PCV line sat against the filter, but not on the inside surface meaning the filter was doing it's job of keeping contaminants out of the intake. Also, these motors ran thick 'ole 25W50 meaning there wouldn't be as much vaporised oil getting up the line & needing to be filtered out in the first place). On the JK's 3.8L however the PVC line runs straight from the PCV valve directly into the upper intake manifold, bypassing the air filter entirely. A member here fitted a catch-can to his 3.8L's PCV line (with a clear sightglass so the oil level could be clearly seen in the pictures he provided) and captured several fluid ounces of 5W20 in it in a little over a week."
http://www.conceptualpolymer.com/PCV...oval%20102.pdf
This guy wrote up some great info on implementing an oil catch can on his LS1 engine. It seems like this is not really a viable option for JKs
"*I also intend to fit a catch-can to the PVC line to further minimise the amount of oil entering the intake. On previous vehicles I've owned in the past, the PCV line from the rocker cover ran to the outside of the air cleaner and had a sponge attached (which you removed and cleaned/replaced periodically) which would filter out most of the oil coming up the line, with the rest being captured by the air filter itself (oil could be clearly seen on the outside surface of the filter media at the precise spot where the sponge-capped PCV line sat against the filter, but not on the inside surface meaning the filter was doing it's job of keeping contaminants out of the intake. Also, these motors ran thick 'ole 25W50 meaning there wouldn't be as much vaporised oil getting up the line & needing to be filtered out in the first place). On the JK's 3.8L however the PVC line runs straight from the PCV valve directly into the upper intake manifold, bypassing the air filter entirely. A member here fitted a catch-can to his 3.8L's PCV line (with a clear sightglass so the oil level could be clearly seen in the pictures he provided) and captured several fluid ounces of 5W20 in it in a little over a week."
http://www.conceptualpolymer.com/PCV...oval%20102.pdf
This guy wrote up some great info on implementing an oil catch can on his LS1 engine. It seems like this is not really a viable option for JKs
12-10-2011, 07:40 AM
#49
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Just came across this thread. Sorry to hear about all the oil and bearing issues. I will say that if you are adding 3 quarts every 3000 miles, then you really don't need to change your oil at all. It's virtually new all the time. Perhaps just spin on a new filter every 4 to 6 K. As far a driving the engine hard???? The harder you work the engine, the wear & tear & oil consumtion naturally goes up.
Many engines will "burn off" oil until it reaches a certain volume. Lets just say that the 3.8L motor is "happy" with 4.35 quarts in it. Every ounce over this amount will be burned off. 4.35 is the Default oil level. So, if you're checking your oil level & it is down .5 quarts, naturally you put in a half a quart, when actually you should leave it alone. My guess is it will take much longer for it to burn the next half a quart.
Mine: 07 X, Castrol GTX 5-20, change every 3K, 85 octane gas, no burning, ticking, knocking. Certainly don't drive it like I stole it.
Many engines will "burn off" oil until it reaches a certain volume. Lets just say that the 3.8L motor is "happy" with 4.35 quarts in it. Every ounce over this amount will be burned off. 4.35 is the Default oil level. So, if you're checking your oil level & it is down .5 quarts, naturally you put in a half a quart, when actually you should leave it alone. My guess is it will take much longer for it to burn the next half a quart.
Mine: 07 X, Castrol GTX 5-20, change every 3K, 85 octane gas, no burning, ticking, knocking. Certainly don't drive it like I stole it.
I just changed to Amsoil 10w40. I am curious what will happen. I also just changed the PCV valve. I will update soon.
12-10-2011, 09:28 PM
#50
JK Super Freak
That would be great if you keep us posted as to how you go on the 10W40 since as I stated in my post, I'm going to start putting in 10W40 at my next oil change in a few months. As well as a reduction in oil consumption, other observations you make such as gains or losses in mileage, power increases (thicker oil can increase compression), reduction in valvetrain noise and smoother running, increase or decrease in incidents of dry-starts, etc would be greatly appreciated. Looking forward to your input!