Spark plug replacement
11-17-16, 10:45 AM
#1
Lead Lap
Thread Starter
Spark plug replacement
I have almost 127,000 miles on the original spark plugs on my 2001 LS430.. The car runs smooth as silk with ample acceleration. I know the recommendation for replacement is 120,000 miles, but I have been informed by a former Lexus Service manager, that as the electrode on the plugs wear and the gap increases, it puts a heavier load on the coils and they have been known to fail. Then of course, the expenses start rising. How many of you have gone beyond the 120,000 mile recommendation and have any of you experienced coil failure? Also, what would be a reasonable cost to replace the plugs with OEM at an independent shop? Should anything else be replaced once at the valve covers (example PCV valve)? The valve cover gaskets were previously replaced. Thanks all.
11-17-16, 11:12 AM
#2
I did a small DIY write up on replacing the spark plugs. While removing them, it was clear one of the plugs was original (not coincidentally, the toughest one to get to)the tech probably just thought nobody would notice and left it on.
So I had an original spark plug with 160k miles or so miles and no codes and no issues.
I would wager 99% of the time, someone in your shoes would be fine not replacing the spark plugs for a while longer. A Lexus dealer will charge about $400-$500 for the job, and nothing else besides the plugs being replaced needs to be done as the valve covers don't come off.
So if you plan on keeping the car "forever" then I would suggest you might as well get them done. If you're not sure if it will be another year or so, would probably be fine leaving them as is.
It's not like the old days where fresh plugs made the car run a lot better and they needed to be changed on a regular basis.
So I had an original spark plug with 160k miles or so miles and no codes and no issues.
I would wager 99% of the time, someone in your shoes would be fine not replacing the spark plugs for a while longer. A Lexus dealer will charge about $400-$500 for the job, and nothing else besides the plugs being replaced needs to be done as the valve covers don't come off.
So if you plan on keeping the car "forever" then I would suggest you might as well get them done. If you're not sure if it will be another year or so, would probably be fine leaving them as is.
It's not like the old days where fresh plugs made the car run a lot better and they needed to be changed on a regular basis.
11-17-16, 12:07 PM
#3
Lexus Fanatic
I was poking around the other day and the driver's bank seems easy to get to....but the pass. side needs the engine cover to come off. The plugs seem really cheap for the Denso iridium or something? Even the Maxima is $12 ea, BMW even more. I plan on DIY at some point, I have all the tools from the BMW job incl locking extensions of various lengths, and a decent calibrated 5-75 ft. lb torque wrench (some say don't use it, I do, and I NEVER use anti-seize)...gotta love the motors that are mounted longitudinally....any my Maxima went from 60 to 220 when the recommended is every 60k....lol
My thing for any car is mpgs, as far as health goes. If the mpgs are same as before, it would seem the motor is generally happy....
My thing for any car is mpgs, as far as health goes. If the mpgs are same as before, it would seem the motor is generally happy....
11-17-16, 12:35 PM
#4
Denso recommends replacing at 60,000 miles. they sell spark plugs so.... I replaced mine at around 95,000 miles and paid $90 for the labor and bought the plugs on ebay for about $50. car really seemed to have a lot more power and started faster and easier.
11-17-16, 01:24 PM
#5
I have not gone past the 120k recommendation. Heck, I pulled out DENSO (IK30) I believe they were, around 60k miles of use, and the electrode didn't look quite so fresh and new and great. I'll post pics of all 8 of them on Saturday or Sunday. FYI, i only use top-tier super from Exxon.
I installed NGK Laser iridium #4589 (IFR6T11).
For the best/iridium plugs, you shouldn't pay more than $6 for each plug. They can easily be found online between $5 to $6 each.
I replaced all the plugs myself. It was the 1st time changing them on the LS. I've done many other cars and the LS isn't that difficult to do. The most difficult part is grasping properly the connection on top of the COP, and pulling it up and off. Of course, you need a couple 3" extensions and a spark plug socket and a swiveling head to really make it easy on you. If you don't have the tools or know-how, then by all means have a shop do them for you. A shop shouldn't charge you any more than 2 hours labor to do these plugs though. I could easily do them in 2 hours or less now that I've done them.
I would definitely ask for the old plugs back. Not only does it keep the mechanics honest, but you'll have an insight into the 'health' of your engine and you can see how much/little they plugs are worn.
Since I did my plugs last weekend, I haven't driven it. I'm unable to tell you if MPG increased or not. I have an EXTREMELY smooth idle now. Not only smooth in comparison to when it was 'missing' because I broke a wire harness, lol, but every once in a slight while, I could 'tell' when I was idling because I could feel a little bit of 'shake' while seated and idling in a parking lot or driveway, etc. My plugs were definitely due to be changed based on their appearance.
When you had your valve cover gaskets replaced, did they check the PCV? Would have been the perfect time. A stuck closed PCV would allow the buildup of blowby and gases and force an oil leak somewhere, like at the gasket/mating surface. On 2004 and newer the PCV screwed into the the valve cover on the driver's side all the way forward. 2003 and older sounds like it was a plastic/rubber grommet (that becomes brittle and breaks off).
To answer your question, you should pay $6x8=$48 for plugs bought online. 2 hours labor at $90/hr + misc shop charges (lol), for no more than $200 for the labor to change them out. That's my estimate at least.
I installed NGK Laser iridium #4589 (IFR6T11).
For the best/iridium plugs, you shouldn't pay more than $6 for each plug. They can easily be found online between $5 to $6 each.
I replaced all the plugs myself. It was the 1st time changing them on the LS. I've done many other cars and the LS isn't that difficult to do. The most difficult part is grasping properly the connection on top of the COP, and pulling it up and off. Of course, you need a couple 3" extensions and a spark plug socket and a swiveling head to really make it easy on you. If you don't have the tools or know-how, then by all means have a shop do them for you. A shop shouldn't charge you any more than 2 hours labor to do these plugs though. I could easily do them in 2 hours or less now that I've done them.
I would definitely ask for the old plugs back. Not only does it keep the mechanics honest, but you'll have an insight into the 'health' of your engine and you can see how much/little they plugs are worn.
Since I did my plugs last weekend, I haven't driven it. I'm unable to tell you if MPG increased or not. I have an EXTREMELY smooth idle now. Not only smooth in comparison to when it was 'missing' because I broke a wire harness, lol, but every once in a slight while, I could 'tell' when I was idling because I could feel a little bit of 'shake' while seated and idling in a parking lot or driveway, etc. My plugs were definitely due to be changed based on their appearance.
When you had your valve cover gaskets replaced, did they check the PCV? Would have been the perfect time. A stuck closed PCV would allow the buildup of blowby and gases and force an oil leak somewhere, like at the gasket/mating surface. On 2004 and newer the PCV screwed into the the valve cover on the driver's side all the way forward. 2003 and older sounds like it was a plastic/rubber grommet (that becomes brittle and breaks off).
To answer your question, you should pay $6x8=$48 for plugs bought online. 2 hours labor at $90/hr + misc shop charges (lol), for no more than $200 for the labor to change them out. That's my estimate at least.
Last edited by LS430inDE.; 11-17-16 at 01:29 PM.
11-17-16, 01:33 PM
#6
I replaced mine at 92K miles and the car felt the exact same before and after. The plugs I took out looked great. I agree with BradTank thoughts on whether you should replace them. Easy DIY job.
LS430inDE: I was harsh on you in your other thread, I hereby apologize. Bad day! Glad you got it sorted out.
LS430inDE: I was harsh on you in your other thread, I hereby apologize. Bad day! Glad you got it sorted out.
11-17-16, 01:38 PM
#7
Aww. Thanks pal. I will admit it took A LOT of resistance and humility to not come back in a more abrasive manner! I expected that on the Honda forums, but HERE!!!!? This is the higher rent district! haha. As they say, alls well that ends well. Apology accepted!
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11-17-16, 03:13 PM
#8
Lead Lap
Thread Starter
Did you purchase OEM plugs on ebay? $50 seems too cheap...I know Denso makes many parts for our cars but I've found out OEM can be different even from a supplier like Denso.
11-17-16, 03:22 PM
#9
Lead Lap
Thread Starter
I was quoted by an independent shop which I have total confidence in $120 labor to change out the plugs. I was encouraged to get only the OEM plugs from Lexus/Toyota. Sometimes Denso is the exact match while other times there are differences. I'll price it out. ...I was told that OEM are about 20 bucks each. $160 for plugs seems like alot. I'll do my research.. .
11-17-16, 05:29 PM
#11
I believe in preventive maintenance but I wouldn't change the plugs until you start having problems. I did this on my LS 400 at 138,000 and the plugs were in great shape. If it ain't broke don't fix it.
11-17-16, 08:09 PM
#12
11-17-16, 11:08 PM
#14
To me it's a no brainer. Lexus recommends changing them out at 120K for good reason. For what little time I've spent on this forum you strike me as someone who is quite meticulous in the care and appearance of his car. I'm surprised that you hadn't had them changed by now. I just picked up a set of Denso SK20R11 plugs from Advance Auto for $6.29 each (after using their online 30% off coupon, TRT30) and plan on changing mine out this weekend. Even though I'm a little bit early with just 111k miles on my car I'm doing all of the maintenence items to bring it up to a known state of condition. I've had my car for about four weeks now. I understand that a lot of people don't have the aptitude to do their own wrenching and that's cool, just find a good indie mechanic to do the job for you at a reasonable cost.
One can always get by by extending out the recommended service intervals. Just because your timing belt is suppose to be changed out at 90K miles doesn't mean that it's going to break at 91k but at some point you start rolling the dice as to how far you want to take things. Someone offering anecdotal information about their experiences with plugs lasting longer than the standard interval doesn't guarantee that you will have the same experience.
Let me ask, if you were buying a car from someone and noticed that they always extended out the maintenance items it would you feel comfortable with buying that car???
One can always get by by extending out the recommended service intervals. Just because your timing belt is suppose to be changed out at 90K miles doesn't mean that it's going to break at 91k but at some point you start rolling the dice as to how far you want to take things. Someone offering anecdotal information about their experiences with plugs lasting longer than the standard interval doesn't guarantee that you will have the same experience.
Let me ask, if you were buying a car from someone and noticed that they always extended out the maintenance items it would you feel comfortable with buying that car???
11-18-16, 05:38 AM
#15
Good point Gronemus.. we want the prior car care to on timely and complete so we feel good about it, then slack off on our own maintenance practices? Doesn't pass the 'sound right' test.
You've made the investment, keep up the maintenance and care and don't let a few dollars get in the way.
My dad is so cheap it's embarrassing... he's the only guy I know that on multiple cars he's burned out the low fuel light because he runs them so long in that condition.
You've made the investment, keep up the maintenance and care and don't let a few dollars get in the way.
My dad is so cheap it's embarrassing... he's the only guy I know that on multiple cars he's burned out the low fuel light because he runs them so long in that condition.