Did spark plug change on STR, and found a big surprise!
#22
03-25-2011, 08:31 PM
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Location: Perth Ontario Canada
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First, modern engines in good condition do not accumulate carbon or any type of deposits in sufficient quantities to make any difference. Trying to dislodge them is attempting fix what's not broken. Pouring in water or using a product developed a half century ago to preserve 2 stroke outboard engines over the winter (Seafoam) is futile at best and could possibly damage the engine or cats at worst. Don't do it.
The OP mentioned needing to replace the cats already. Possibly the root cause of that problem is still there and the plugs are a fortunate warning of what's to come.
There was a mention also of a K&N filter. Has this been repeatedly over oiled and is tossing excess into the combustion chambers?
Oil consumption- OP mentioned adding 1/2 quart or more over 3-4 months. How much driving is that? What do other -R owners see.
My non-R uses zero oil between changes.
#23
03-25-2011, 08:39 PM
Much like the spark plug chart talking about ash from lead, the water trickle thing is about 40 years out of date.
First, modern engines in good condition do not accumulate carbon or any type of deposits in sufficient quantities to make any difference. Trying to dislodge them is attempting fix what's not broken. Pouring in water or using a product developed a half century ago to preserve 2 stroke outboard engines over the winter (Seafoam) is futile at best and could possibly damage the engine or cats at worst. Don't do it.
The OP mentioned needing to replace the cats already. Possibly the root cause of that problem is still there and the plugs are a fortunate warning of what's to come.
There was a mention also of a K&N filter. Has this been repeatedly over oiled and is tossing excess into the combustion chambers?
Oil consumption- OP mentioned adding 1/2 quart or more over 3-4 months. How much driving is that? What do other -R owners see.
My non-R uses zero oil between changes.
First, modern engines in good condition do not accumulate carbon or any type of deposits in sufficient quantities to make any difference. Trying to dislodge them is attempting fix what's not broken. Pouring in water or using a product developed a half century ago to preserve 2 stroke outboard engines over the winter (Seafoam) is futile at best and could possibly damage the engine or cats at worst. Don't do it.
The OP mentioned needing to replace the cats already. Possibly the root cause of that problem is still there and the plugs are a fortunate warning of what's to come.
There was a mention also of a K&N filter. Has this been repeatedly over oiled and is tossing excess into the combustion chambers?
Oil consumption- OP mentioned adding 1/2 quart or more over 3-4 months. How much driving is that? What do other -R owners see.
My non-R uses zero oil between changes.
#25
03-25-2011, 09:08 PM
I read on the forums that its normal for the R's to consume oil more than normal. Even my Jag mechanic pointed that out to me. Plus I'm getting near the 100K so its expected 
.
As for the K&N filter the car use to have one when I bought it, I took it out and dumped it b/c at the time my Jag mechanic said its not worth the risk plus it was filthy dirty. But now I went back and put a brand new one in, and I do feel it sucking more air in than before which is a great thing! Whomever had this car before me, really didn't take care of it and the root cause of it all shouldn't be there still since I replaced the CATS, and Plugs. PLus m o2 sensors never threw out any codes, so they are still good.
** I found a very nice description of all the different types of Spark Plug conditions, take a look at this pdf http://www.boschautoparts.com/Techni...kPlugFaces.pdf
. As for the K&N filter the car use to have one when I bought it, I took it out and dumped it b/c at the time my Jag mechanic said its not worth the risk plus it was filthy dirty. But now I went back and put a brand new one in, and I do feel it sucking more air in than before which is a great thing! Whomever had this car before me, really didn't take care of it and the root cause of it all shouldn't be there still since I replaced the CATS, and Plugs. PLus m o2 sensors never threw out any codes, so they are still good.
** I found a very nice description of all the different types of Spark Plug conditions, take a look at this pdf http://www.boschautoparts.com/Techni...kPlugFaces.pdf
Last edited by jag79; 03-26-2011 at 01:12 AM.
#26
03-25-2011, 10:47 PM
Veteran Member
For anyone that cares, the 100,000 mile sparkplug change interval is only specified for North American naturally aspirated engines on unleaded.
Everywhere else it is 30,0000 miles for the same plug and engine on unleaded.
The 100,000 mile thing is either a marketing creation or a regulatory creation.
Everywhere else it is 30,0000 miles for the same plug and engine on unleaded.
The 100,000 mile thing is either a marketing creation or a regulatory creation.
Last edited by plums; 03-25-2011 at 10:49 PM.
#27
03-25-2011, 11:00 PM
Veteran Member
Possibly because they were told not to ... by the maintenance schedule.
Carmakers are in a quandary now. Cars are now capable with good care of lasting many, many years.
If people take car of their cars, like their cars and don't buy new ones ... what are carmakers supposed to sell? Toasters?
Luckily for carmakers, the current market loves "no maintenance, sealed for life".
Carmakers have to produce well engineered cars to compete, they don't necessarily want you to benefit from it. 3 year replacement cycles are good for repeat business. 10 years? Not so much.
Carmakers are in a quandary now. Cars are now capable with good care of lasting many, many years.
If people take car of their cars, like their cars and don't buy new ones ... what are carmakers supposed to sell? Toasters?
Luckily for carmakers, the current market loves "no maintenance, sealed for life".
Carmakers have to produce well engineered cars to compete, they don't necessarily want you to benefit from it. 3 year replacement cycles are good for repeat business. 10 years? Not so much.
#28
03-26-2011, 12:42 AM
For anyone that cares, the 100,000 mile sparkplug change interval is only specified for North American naturally aspirated engines on unleaded.
Everywhere else it is 30,0000 miles for the same plug and engine on unleaded.
The 100,000 mile thing is either a marketing creation or a regulatory creation.
Everywhere else it is 30,0000 miles for the same plug and engine on unleaded.
The 100,000 mile thing is either a marketing creation or a regulatory creation.
#29
03-26-2011, 03:39 AM
Veteran Member
I thought the 100000 mile thing was because of Iridiums. I'm confused now. I pulled the plugs on my wifes Pontiac that she has had since new and it has 130000 miles and the Iridiums still look new and they are original. So are you saying that Iridiums are only 30000 mile plugs?? Both my Jag and her Pontiac had long life Iridiums and still looked great when removed. I replaced mine since I had already bought them but the wifes I just checked the gap which was still dead on and threw them back in and will check again at the next oil change. Can you please shed some light on the 30000 vs the 100000 please?
The 30k/100k specification is found in JTIS. For the exact same plug which is specified for unleaded gas, only North America has a recommended change interval of 100K. The rest of the world is 30K or less.
Furthermore, even for North American SC engines, the interval is 60K. Yet everyone runs around with this 100K number.
There are four possibilities for this special treatment for the North American market.
1. North Americans are less demanding of their engines
2. North Americans want to be told and sold zero maintenance
3. US EPA requires 100K no maintenance (mentioned in another thread)
4. North American unleaded gas is three times better than everyone else's unleaded gas
Discount #1 and #4 as being ludicrous.
That leaves #2 and #3 as reasonable suspects.
The reason that platinum/iridium plugs have very fine center electrodes is to maintain a passable resemblance to a clean firing gap.
But, in another thread, someone posted large magnification photos of their plug tips.
I pointed out that you could see the metal transfer rounding the electrodes.
Sparkplug electrodes like sharp edges. They fire better. That's why racers file center electrodes flat and file back the ground electrode. It is also good for your coils because an easier spark demands less of the coil.
There is a difference between a sparkplug that will fire and a spark plug that fires well. It is also the difference between a completely smooth idle and the occasional miss.
So, platinum/iridium are helpful in gaining passable performance to higher mileages without complete failure. But, to expect 100K is really stretching it.
At the current time, NGK platinum plugs carry only a very small premium to copper plugs. Iridiums are double the platinums. A reasonable alternative to stretching the iridiums to their maximum because of the cost would be to use the equivalent platinums and change at 30K like the rest of the world or even more frequently.
By doing so, you have fresh plugs in your engine more frequently. Plugs will start to deteriorate as soon as you fire up the first time. What you want is to be able to refresh them on a reasonable basis. Reasonable is of course completely subjective.
the bottom line is that when marketing and regulatory considerations are taken out of the equation, the manufacturer presents a different change interval. it is likely to be the more correct one.
it is already accepted here that there is no such thing as a sealed for life automatic transmission. this is no different.
ps. Do not use the Bosch plugs. They are just a bit longer than the NGK at the nose.
NGK has also updated the recommended heat range over the years by going 1 heat range colder than original spec. It was 5, it is now 6. The original spec may have been targetted to burning off carbon to reach that special 100K number. But, knock will come sooner.
Last edited by plums; 03-26-2011 at 03:46 AM.
#31
03-26-2011, 05:21 AM
Veteran Member
JTIS ceased in about 2004. I have the revised Maintenance Check Sheets from jag's GTR (now TOPIx) for the various post-2002.5MY S-Type models (including diesel and petrol cars). Even the Arduous markets one says 50K miles for the V8. The others say 100K.
e.g. for my car, JLR 11 62 10_1E dated 31/5/2006
(Anyone can join TOPIx and download these as PDFs easily.)
Denso and others make a point that the plugs last a long time. I wouldn't like to say 100K because I have no engineering qualifications relevant but I find it hard to believe 30K. If anyone has the right qualifications and experience please say so!
One of the reasons for using platinum is that it is very resistant to wear (especially evaporation etc) due to heat or due to sparking. Iridium is more resistant, is my understanding.
None of this is meant to take away that jag79's plugs look worrying. I'd be pulling the new ones at say 5K or 10K to see they're not going the same way. But I'd be checking fuel trims etc NOW and OFTEN. Lack of codes does NOT mean an engine is running perfectly.
e.g. for my car, JLR 11 62 10_1E dated 31/5/2006
(Anyone can join TOPIx and download these as PDFs easily.)
Denso and others make a point that the plugs last a long time. I wouldn't like to say 100K because I have no engineering qualifications relevant but I find it hard to believe 30K. If anyone has the right qualifications and experience please say so!
One of the reasons for using platinum is that it is very resistant to wear (especially evaporation etc) due to heat or due to sparking. Iridium is more resistant, is my understanding.
None of this is meant to take away that jag79's plugs look worrying. I'd be pulling the new ones at say 5K or 10K to see they're not going the same way. But I'd be checking fuel trims etc NOW and OFTEN. Lack of codes does NOT mean an engine is running perfectly.
#32
03-26-2011, 06:31 AM
there are 2 types of iridiums reg and long life. On the long life it is easy to get 100,000 plus I have before and looked new.
My 4.2 non R has had 2,000 miles on the oil change so far with zero usage my car has 100,000 miles on it.
I believe it is not normal for these engines to use any oil, if they do there is a root problem. I would do a compression test now. Trust me this could save you a engine. The testers on cost 20 dollars at harbor freight.
My 4.2 non R has had 2,000 miles on the oil change so far with zero usage my car has 100,000 miles on it.
I believe it is not normal for these engines to use any oil, if they do there is a root problem. I would do a compression test now. Trust me this could save you a engine. The testers on cost 20 dollars at harbor freight.
#33
03-26-2011, 09:04 AM
Join Date: Oct 2009
Location: Perth Ontario Canada
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There's plenty of hard evidence to support a 100K mile plug life, not just on Jaaaaaags, but on just about any type of modern car. I'd be curious to know why a 30K change interval is mentioned for non-N.Am cars.
Either way, none of this has anything to do with the OPs problem with the removed plugs.
Either way, none of this has anything to do with the OPs problem with the removed plugs.
#34
03-26-2011, 09:32 AM
there are 2 types of iridiums reg and long life. On the long life it is easy to get 100,000 plus I have before and looked new.
My 4.2 non R has had 2,000 miles on the oil change so far with zero usage my car has 100,000 miles on it.
I believe it is not normal for these engines to use any oil, if they do there is a root problem. I would do a compression test now. Trust me this could save you a engine. The testers on cost 20 dollars at harbor freight.
My 4.2 non R has had 2,000 miles on the oil change so far with zero usage my car has 100,000 miles on it.
I believe it is not normal for these engines to use any oil, if they do there is a root problem. I would do a compression test now. Trust me this could save you a engine. The testers on cost 20 dollars at harbor freight.
I believe that apart of the rental tools at Autozone also. So you can just get one there use it then just return it.
Sure thing.
The 30k/100k specification is found in JTIS. For the exact same plug which is specified for unleaded gas, only North America has a recommended change interval of 100K. The rest of the world is 30K or less.
Furthermore, even for North American SC engines, the interval is 60K. Yet everyone runs around with this 100K number.
There are four possibilities for this special treatment for the North American market.
1. North Americans are less demanding of their engines
2. North Americans want to be told and sold zero maintenance
3. US EPA requires 100K no maintenance (mentioned in another thread)
4. North American unleaded gas is three times better than everyone else's unleaded gas
Discount #1 and #4 as being ludicrous.
That leaves #2 and #3 as reasonable suspects.
The reason that platinum/iridium plugs have very fine center electrodes is to maintain a passable resemblance to a clean firing gap.
But, in another thread, someone posted large magnification photos of their plug tips.
I pointed out that you could see the metal transfer rounding the electrodes.
Sparkplug electrodes like sharp edges. They fire better. That's why racers file center electrodes flat and file back the ground electrode. It is also good for your coils because an easier spark demands less of the coil.
There is a difference between a sparkplug that will fire and a spark plug that fires well. It is also the difference between a completely smooth idle and the occasional miss.
So, platinum/iridium are helpful in gaining passable performance to higher mileages without complete failure. But, to expect 100K is really stretching it.
At the current time, NGK platinum plugs carry only a very small premium to copper plugs. Iridiums are double the platinums. A reasonable alternative to stretching the iridiums to their maximum because of the cost would be to use the equivalent platinums and change at 30K like the rest of the world or even more frequently.
By doing so, you have fresh plugs in your engine more frequently. Plugs will start to deteriorate as soon as you fire up the first time. What you want is to be able to refresh them on a reasonable basis. Reasonable is of course completely subjective.
the bottom line is that when marketing and regulatory considerations are taken out of the equation, the manufacturer presents a different change interval. it is likely to be the more correct one.
it is already accepted here that there is no such thing as a sealed for life automatic transmission. this is no different.
ps. Do not use the Bosch plugs. They are just a bit longer than the NGK at the nose.
NGK has also updated the recommended heat range over the years by going 1 heat range colder than original spec. It was 5, it is now 6. The original spec may have been targetted to burning off carbon to reach that special 100K number. But, knock will come sooner.
The 30k/100k specification is found in JTIS. For the exact same plug which is specified for unleaded gas, only North America has a recommended change interval of 100K. The rest of the world is 30K or less.
Furthermore, even for North American SC engines, the interval is 60K. Yet everyone runs around with this 100K number.
There are four possibilities for this special treatment for the North American market.
1. North Americans are less demanding of their engines
2. North Americans want to be told and sold zero maintenance
3. US EPA requires 100K no maintenance (mentioned in another thread)
4. North American unleaded gas is three times better than everyone else's unleaded gas
Discount #1 and #4 as being ludicrous.
That leaves #2 and #3 as reasonable suspects.
The reason that platinum/iridium plugs have very fine center electrodes is to maintain a passable resemblance to a clean firing gap.
But, in another thread, someone posted large magnification photos of their plug tips.
I pointed out that you could see the metal transfer rounding the electrodes.
Sparkplug electrodes like sharp edges. They fire better. That's why racers file center electrodes flat and file back the ground electrode. It is also good for your coils because an easier spark demands less of the coil.
There is a difference between a sparkplug that will fire and a spark plug that fires well. It is also the difference between a completely smooth idle and the occasional miss.
So, platinum/iridium are helpful in gaining passable performance to higher mileages without complete failure. But, to expect 100K is really stretching it.
At the current time, NGK platinum plugs carry only a very small premium to copper plugs. Iridiums are double the platinums. A reasonable alternative to stretching the iridiums to their maximum because of the cost would be to use the equivalent platinums and change at 30K like the rest of the world or even more frequently.
By doing so, you have fresh plugs in your engine more frequently. Plugs will start to deteriorate as soon as you fire up the first time. What you want is to be able to refresh them on a reasonable basis. Reasonable is of course completely subjective.
the bottom line is that when marketing and regulatory considerations are taken out of the equation, the manufacturer presents a different change interval. it is likely to be the more correct one.
it is already accepted here that there is no such thing as a sealed for life automatic transmission. this is no different.
ps. Do not use the Bosch plugs. They are just a bit longer than the NGK at the nose.
NGK has also updated the recommended heat range over the years by going 1 heat range colder than original spec. It was 5, it is now 6. The original spec may have been targetted to burning off carbon to reach that special 100K number. But, knock will come sooner.
#35
03-26-2011, 09:45 AM
Veteran Member
The comments also noted that the plugs need to be seen under magnification to easily see the effects. Luckily someone uploaded the photos last week.
And as always ... YMMV in these matters. It is not being suggested that you or anyone else must change plugs at any frequency that does not please you.
#36
03-26-2011, 09:45 AM
Veteran Member
Oil usage will vary. It is entirely normal for an engine to use oil. In fact most manufactures will not do anything unless you are using 1 qt/1000 miles or more. Big fight on the Porsche forums as some cars were using 1000 mile/quart from new and Porsche said it was withing tolerance.
My 2005 STR uses about 1 qt every 5-6.5K miles. Depends on how it's driven. Short trips and rush hour traffic it will use more. All highway miles and I can almost get to 7.5 K miles which is when I change oil. You can vary the oil weights and brands around to see how your car's oil consumption changes. Some people have a had good luck with the high mileage type oils. I use Mobil 1 5W-30 now. Before it was Castrol 5W-30 as Jaguar recommends.
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My 2005 STR uses about 1 qt every 5-6.5K miles. Depends on how it's driven. Short trips and rush hour traffic it will use more. All highway miles and I can almost get to 7.5 K miles which is when I change oil. You can vary the oil weights and brands around to see how your car's oil consumption changes. Some people have a had good luck with the high mileage type oils. I use Mobil 1 5W-30 now. Before it was Castrol 5W-30 as Jaguar recommends.
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#37
03-26-2011, 09:53 AM
Veteran Member
As for why 30K for the rest of the world, it is a Jaguar recommendation. It would be reasonable to believe that they would have also liked to say 100K if they fellt confident with it.
100K is likely the result of marketing and regulatory influence because the engine did not change nor did the engineers.
Again, if you are happy with 100K ... go for it.
#38
03-26-2011, 10:04 AM
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Well, we're still drifting off topic but I've seen no evidence inferring that there's anything to gain by reducing the interval. Same with oil change intervals.
If a car goes to the graveyard with the original engine and having followed the OEM's schedule, what would be gained by second guessing shorter interval on any mtce. task?
As the old burger commercial stated: show me the beef.
If a car goes to the graveyard with the original engine and having followed the OEM's schedule, what would be gained by second guessing shorter interval on any mtce. task?
As the old burger commercial stated: show me the beef.
#39
03-26-2011, 10:12 AM
Veteran Member
But, the engine itself did not suddenly morph overnight because managment decided to change the method of information delivery or extend the change interval.
They still stick to the mantra that the automatic transmission is a non-service component. Does anyone here really believe that?
And that is the real thrust .. what is reasonable versus what is recommended.
#40
03-26-2011, 10:15 AM
Veteran Member
You said "hard evidence" for your view ... where is it?
As for the contrarian point of view ... pull plugs, look at electrodes using 30x magnifying loupe. Or, look at the pictures from a user posting last week.
Gotta go deliver a car now ... back later.
As for the contrarian point of view ... pull plugs, look at electrodes using 30x magnifying loupe. Or, look at the pictures from a user posting last week.
Gotta go deliver a car now ... back later.