Please look at my spark plugs
#1
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Please look at my spark plugs
Hello, I am a newbie when it comes to the RX8. I have been working on cars for well over 15 years, but I do understand this is an entirely different animal and none of my past experience will really carry over.
I changed my spark plugs today at 33,000 miles (car is 2009 model). It was running just fine, but I am trying to keep up with all maintenance per the schedule.
I noticed there was a lot of tan colored carbon buildup on the plugs. Hopefully somebody can take a look and tell me if this is normal or not.
Car runs fine, gets 22-23 mpg on highway (60-65 mph), has had oil changes with GTX 5w-20 every 3,000, transmission and rear end fluids changed once, air filter changed twice. Picture will be attached, thanks for taking a look!
I changed my spark plugs today at 33,000 miles (car is 2009 model). It was running just fine, but I am trying to keep up with all maintenance per the schedule.
I noticed there was a lot of tan colored carbon buildup on the plugs. Hopefully somebody can take a look and tell me if this is normal or not.
Car runs fine, gets 22-23 mpg on highway (60-65 mph), has had oil changes with GTX 5w-20 every 3,000, transmission and rear end fluids changed once, air filter changed twice. Picture will be attached, thanks for taking a look!
#2
Thats about how mine looked coming out of my 2010 MT after 20K miles less that amount of carbon. I did have some carbon on my back rotor trailing plug, but no where near as heavy as 2nd most carboned you show. I couldnt tell if I needed new plugs or not, but changed on that interval to be safe.
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Thats about how mine looked coming out of my 2010 MT after 20K miles less that amount of carbon. I did have some carbon on my back rotor trailing plug, but no where near as heavy as 2nd most carboned you show. I couldnt tell if I needed new plugs or not, but changed on that interval to be safe.
#5
2009 RX-8 Touring
4-cycle piston engines need two crankshaft rotations to finish one combustion cycle per chambers. 4-cycle rotary engines need to three crankshaft rotations to do the same. Rotary engines will always need to rotate 50% faster than piston engines because of their design. The 9000rpm redline on a rotary engine is comparable to a 6000rpm redline on a piston engine; they're not extra bonus RPMs you can use when you want, they're required RPMs for the engine to achieve its specified power output.
Last edited by fyrstormer; 10-30-2012 at 09:08 PM.
#6
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where do people keep getting that this engine has a 9K rpm redline? It doesn't. Please search.
Recommended redline is approx 8.2 K--to 8.5K max. if you are interested in your engine lasting --that is.
Dont forget you still have an e shaft etc flying around in there. Yes the rotors turn slower but the bearings etc all take a beating from constant high rpms.
Redline a day doesnt do squat for carbon buidup. Sorry.
Recommended redline is approx 8.2 K--to 8.5K max. if you are interested in your engine lasting --that is.
Dont forget you still have an e shaft etc flying around in there. Yes the rotors turn slower but the bearings etc all take a beating from constant high rpms.
Redline a day doesnt do squat for carbon buidup. Sorry.
#9
Super Moderator
Plugs are normal...and Denny (OD) is spot on...
As for 'the' Red-line a day mantra, again as OD says, you will never prevent carbon build up in your RX-8, particularly S2's which has no AP available so they remain a rich running engine.
Yes, a few high RPM changes are good for engine each day (use), (won't stop carbon build up) helps to keep spark plugs in a better running condition...also helps to keep SSV, VDI valves in a working order.
Revving engine past tacho red-line will do more engine harm than good (long term).
As for 'the' Red-line a day mantra, again as OD says, you will never prevent carbon build up in your RX-8, particularly S2's which has no AP available so they remain a rich running engine.
Yes, a few high RPM changes are good for engine each day (use), (won't stop carbon build up) helps to keep spark plugs in a better running condition...also helps to keep SSV, VDI valves in a working order.
Revving engine past tacho red-line will do more engine harm than good (long term).
#11
Rockie Mountain Newbie
I noticed there was a lot of tan colored carbon buildup on the plugs. Hopefully somebody can take a look and tell me if this is normal or not.
Car runs fine, gets 22-23 mpg on highway (60-65 mph), has had oil changes with GTX 5w-20 every 3,000, transmission and rear end fluids changed once, air filter changed twice. Picture will be attached, thanks for taking a look!
Car runs fine, gets 22-23 mpg on highway (60-65 mph), has had oil changes with GTX 5w-20 every 3,000, transmission and rear end fluids changed once, air filter changed twice. Picture will be attached, thanks for taking a look!
Our oil change intervals are the same, though I use Pennzoil instead.
I also have changed the trans and rear diff fluids once, also.
No matter what you do, mileage will be the same.
And as long as your OMP keeps giving the engine oil, the plugs will always look the same, too.
BC.
#14
2009 RX-8 Touring
I think you're thinking of the yellow-line around 8250rpm, which is when the shift beep sounds. (I have no idea if that's what it's really called, but older cars I've seen actually have a yellow line before the redline, hence my name for it.) The only reason that's there is to give the driver time to react before exceeding the redline at 9000rpm.
Anyway, your response completely ignored the majority of my post and ranted about a single number therein, so...have a nice day.
Last edited by fyrstormer; 11-01-2012 at 01:28 AM.
#15
The Heavy Metal Scientist
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I get it from my tachometer, which shows a series of red lines past 9000rpm. Forgive me for being obtuse, but I'm pretty sure they wouldn't put the redline on the tach at 9000rpm if it were unreasonably risky to rev that high.
I think you're thinking of the yellow-line around 8250rpm, which is when the shift beep sounds. (I have no idea if that's what it's really called, but older cars I've seen actually have a yellow line before the redline, hence my name for it.) The only reason that's there is to give the driver time to react before exceeding the redline at 9000rpm.
Anyway, your response completely ignored the majority of my post and ranted about a single number therein, so...have a nice day.
I think you're thinking of the yellow-line around 8250rpm, which is when the shift beep sounds. (I have no idea if that's what it's really called, but older cars I've seen actually have a yellow line before the redline, hence my name for it.) The only reason that's there is to give the driver time to react before exceeding the redline at 9000rpm.
Anyway, your response completely ignored the majority of my post and ranted about a single number therein, so...have a nice day.
Directly from Racing Beats website (but what do they know)
"If you intend your race engine to run above 8,500 RPM or if the engine is a non-standard assembly, we recommend balancing the rotating assembly. The rotating assembly includes both rotors, main pulley, front and rear counterweights, and the eccentric shaft. We also recommend balancing the pressure plate and the flywheel on the rotating assembly.
In our experience it is not necessary to re-balance a stock or mildly modified engine operating below 8,500 RPM if the rotating parts were originally intended by Mazda to be used together."
#16
Registered
You missed fyrstormers point altogether. The tac SHOWS a 9k rpm redline, so that is the redline. Sure there may be other suggested rpms to go up to instead but the redline is 9k. This is like arguing that a stop sign is purple. When you hit 9k rpm on the tach you are actually less than that by up to 500 rpm I believe so even if you think you hit 9k you really didn't in most cases. I'm not sure if it is always that inaccurate but I know it can be.
#19
2009 RX-8 Touring
you missed OD's point all together. OD is describing the redline at which point engine damage occurs not what shows on your dash.
Directly from Racing Beats website (but what do they know)
"If you intend your race engine to run above 8,500 RPM or if the engine is a non-standard assembly, we recommend balancing the rotating assembly. The rotating assembly includes both rotors, main pulley, front and rear counterweights, and the eccentric shaft. We also recommend balancing the pressure plate and the flywheel on the rotating assembly.
In our experience it is not necessary to re-balance a stock or mildly modified engine operating below 8,500 RPM if the rotating parts were originally intended by Mazda to be used together."
Directly from Racing Beats website (but what do they know)
"If you intend your race engine to run above 8,500 RPM or if the engine is a non-standard assembly, we recommend balancing the rotating assembly. The rotating assembly includes both rotors, main pulley, front and rear counterweights, and the eccentric shaft. We also recommend balancing the pressure plate and the flywheel on the rotating assembly.
In our experience it is not necessary to re-balance a stock or mildly modified engine operating below 8,500 RPM if the rotating parts were originally intended by Mazda to be used together."
Also, you're using a quote about a race engine to back up an argument about a stock engine. That right there should be a clear sign your comparison is invalid. Race engines get the **** beaten out of them a lot more than stock engines do. Revving to 9000 a few times a week will do nothing significant to my engine, because I normally keep it below 6000, and I cruise around 3000. A race engine cruises much higher, because the car is going faster and accelerating harder.
Redline starts at 9000 on my tach. Yellow-line starts at 8500. When you hit yellow-line, that's your cue to hurry up and shift. It does not mean "abandon all hope, ye who enter here".
Last edited by fyrstormer; 11-02-2012 at 03:54 PM.
#20
05 RX8 Sold///05 Evo VIII
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Just give up and chuckle when he's in for engine replacement.
Furthermore shifting that high is NOT good for our transmissions at all. They don't like 9K shifts, many people know this the hard way.
Anyway. OP those plugs look pretty standard for 30k. I do mine every 20 or so. If you want to save money, buy the spark plug cleaner from harbor freight. They clean up great!
I'll post pics when I get a chance.
Flooded plugs.
Cleaned up.
Carboned plugs, 25k
Cleaned up.
Furthermore shifting that high is NOT good for our transmissions at all. They don't like 9K shifts, many people know this the hard way.
Anyway. OP those plugs look pretty standard for 30k. I do mine every 20 or so. If you want to save money, buy the spark plug cleaner from harbor freight. They clean up great!
I'll post pics when I get a chance.
Flooded plugs.
Cleaned up.
Carboned plugs, 25k
Cleaned up.
Last edited by viprez586; 11-02-2012 at 04:04 PM.
#23
running on double cream!
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I used the fact that he said "spark plug cleaner from harbor freight" and used my google-fu which led me to this..
Pneumatic Spark Plug Cleaner
Pneumatic Spark Plug Cleaner
#24
no agenda
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I used the fact that he said "spark plug cleaner from harbor freight" and used my google-fu which led me to this..
Pneumatic Spark Plug Cleaner
Pneumatic Spark Plug Cleaner
Was reading/posting from my phone.
Thanks for the linky
edit:
Hmmm interesting. Can you google the forum for me too please too see what kind of success people have had with this?
I'm not convinced ... I always use fresh plugs
I thought I read somewhere that the plugs were only coated in iridium and such a procedure would remove that.
I'm being lazy however and not doing any checking first
Last edited by wcs; 11-03-2012 at 07:04 AM.
#25
Registered
I would check the gap after cleaning see if they are still in spec.
also on a side note, I notices some MIAC sound when I floor it at lower rpm usually around 3-4. it happens only when I floor it. maybe time for new plugs? I have 23k on the clock. no CEL or flashing CEL.
also on a side note, I notices some MIAC sound when I floor it at lower rpm usually around 3-4. it happens only when I floor it. maybe time for new plugs? I have 23k on the clock. no CEL or flashing CEL.