Under-Torqued Spark Plugs
05-02-23, 04:24 AM
#31
Use it or not, I'd just warn you not to learn the hard way as it can be painful and expensive to fix.
...and by the way, Denso isn't liable if your spark plug seizes in you cylinder head. Absolutely no liability there for them.
Good luck with your 1st spark plug change, but if you will do a second on your GS, I'd recommend using a little anti seize on each plug. There are write-ups on how to apply properly. You can avoid cross threading during installation by not wearing work gloves and feeling the socket/extension with your bare fingers. Be careful with seating the plug, and just twist slowly, you'll know if the threads aren't engaged properly.
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JeffKeryk (05-02-23)
05-02-23, 05:45 AM
#32
I think people are missing the main point for why you use anti-seize. It's not so much to help thread spark plugs in initially, it's for those DIYers who will remove them in the future. This won't apply to those who leave their spark plugs in forever, only those who want to remove spark plugs at the scheduled maintenance interval (or later), but find the plug seized in the aluminum head. Speak with a mechanic who has busted off a spark plug, or stripped out the threads in an aluminum head. If you ever have this situation, you'd curse yourself for not using a little anti-seize when you originally installed the spark plugs. It's used to prevent a problem in the future.
Use it or not, I'd just warn you not to learn the hard way as it can be painful and expensive to fix.
...and by the way, Denso isn't liable if your spark plug seizes in you cylinder head. Absolutely no liability there for them.
Good luck with your 1st spark plug change, but if you will do a second on your GS, I'd recommend using a little anti seize on each plug. There are write-ups on how to apply properly. You can avoid cross threading during installation by not wearing work gloves and feeling the socket/extension with your bare fingers. Be careful with seating the plug, and just twist slowly, you'll know if the threads aren't engaged properly.
Use it or not, I'd just warn you not to learn the hard way as it can be painful and expensive to fix.
...and by the way, Denso isn't liable if your spark plug seizes in you cylinder head. Absolutely no liability there for them.
Good luck with your 1st spark plug change, but if you will do a second on your GS, I'd recommend using a little anti seize on each plug. There are write-ups on how to apply properly. You can avoid cross threading during installation by not wearing work gloves and feeling the socket/extension with your bare fingers. Be careful with seating the plug, and just twist slowly, you'll know if the threads aren't engaged properly.
I’ve never had an issue removing a spark plug and non of them had anti seize. I removed my factory plugs after 100k miles zero issues. I recommend against using any anti seize. If you look at the FSM, Lexus does NOT use anti seize. You always turn the plug by hand(with socket extension) to start and then use rachet.
Also get this tool. It’s a magnetic socket with an 11” extension that pivots attached to it. Makes the job a lot easier.
05-02-23, 06:05 AM
#33
Pole Position
This is correct and if you believe any dealership is using a torque wrench to tighten anything other than cyl heads or engine internals you are dreaming.
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munkjeep (02-03-24)
05-02-23, 06:58 AM
#34
Lexus Test Driver
I’ve never had an issue removing a spark plug and non of them had anti seize. I removed my factory plugs after 100k miles zero issues. I recommend against using any anti seize. If you look at the FSM (Factory Service Manual) , Lexus does NOT use anti seize. You always turn the plug by hand(with socket extension) to start and then use rachet.
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JDR76 (05-02-23)
05-02-23, 09:21 AM
#36
I bet you are over torquing the plugs. 15 ft lbs ain't much. And I bet there is nothing wrong with your process.
05-02-23, 09:24 AM
#37
I think people are missing the main point for why you use anti-seize. It's not so much to help thread spark plugs in initially, it's for those DIYers who will remove them in the future. This won't apply to those who leave their spark plugs in forever, only those who want to remove spark plugs at the scheduled maintenance interval (or later), but find the plug seized in the aluminum head. Speak with a mechanic who has busted off a spark plug, or stripped out the threads in an aluminum head. If you ever have this situation, you'd curse yourself for not using a little anti-seize when you originally installed the spark plugs. It's used to prevent a problem in the future.
Use it or not, I'd just warn you not to learn the hard way as it can be painful and expensive to fix.
...and by the way, Denso isn't liable if your spark plug seizes in you cylinder head. Absolutely no liability there for them.
Good luck with your 1st spark plug change, but if you will do a second on your GS, I'd recommend using a little anti seize on each plug. There are write-ups on how to apply properly. You can avoid cross threading during installation by not wearing work gloves and feeling the socket/extension with your bare fingers. Be careful with seating the plug, and just twist slowly, you'll know if the threads aren't engaged properly.
Use it or not, I'd just warn you not to learn the hard way as it can be painful and expensive to fix.
...and by the way, Denso isn't liable if your spark plug seizes in you cylinder head. Absolutely no liability there for them.
Good luck with your 1st spark plug change, but if you will do a second on your GS, I'd recommend using a little anti seize on each plug. There are write-ups on how to apply properly. You can avoid cross threading during installation by not wearing work gloves and feeling the socket/extension with your bare fingers. Be careful with seating the plug, and just twist slowly, you'll know if the threads aren't engaged properly.
Antiseize, used properly, makes a lotta sense and has zero downside.
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93SCMax (05-02-23)
05-02-23, 10:32 AM
#38
Lexus Test Driver
Maybe your explanation might help you to make your case and defend your conviction for using anti-seize screw thread lubricant even against the explicit directions of all spark plug manufacturers (AC, Autolite, Champion, KLG, NGK, Bosch and Denso) as well as Toyota/Lexus. I'm always open to learning if companies like Denso and Lexus are providing incorrect information or at odds with top respected mechanics.
Last edited by bclexus; 05-02-23 at 11:23 AM. Reason: orthography
05-02-23, 11:00 AM
#39
Pole Position
I had a service truck with a 5.4 engine that was serviced at the dealer, we weren't allowed to work on the service trucks ourselves for lease and insurance reasons.
Both heads were replaced because a few s/plugs were seized in the head and couldn't be repaired, no warranty. Antiseize would've prevented that.
I use anti seize for my own stuff but have never used it for customers, I know clean dry threads are recommended for a lot of things but I have never put an engine together bone dry on things like rod and main bearing bolts especially on torque to yield head bolts. If a spark plug or even a wheel comes loose you will get lots of warning before any damage can happen.
Both heads were replaced because a few s/plugs were seized in the head and couldn't be repaired, no warranty. Antiseize would've prevented that.
I use anti seize for my own stuff but have never used it for customers, I know clean dry threads are recommended for a lot of things but I have never put an engine together bone dry on things like rod and main bearing bolts especially on torque to yield head bolts. If a spark plug or even a wheel comes loose you will get lots of warning before any damage can happen.
05-02-23, 11:06 AM
#40
This is becoming ridiculous. Come on Guys. If others see these post they are going to think the 4th Gen are really very incompetentwith the simple task way of changing the plugs on one the easiest engines out there.
Tightening down with hand turns not over done is OK. Why we would be arguing about using the specified tq with a tq wrench spec is hard to understand. it's OK.
Using a little anti-seize to keep the plugs from seizing's due to some suggesting leaving the plugs in for a lifetime is OK.
Not using any anti-seize is also...OK.
Be careful that we don't go back and pull post that contradict, = just do what Lexus says, just do what the part manufacture says, then showing a 360 of things like the Trans threads, vs now saying don't do what they say do. For the Record not just b/c, .... including myself and other also. Everyone has their own way of being right but wrong, and/or wrong but right. If your Boat floats your way it Floats. Information wise, we should be documenting when to do, how to, things to be careful about, and useful info. Yes I have been known to do things the wrong way too. I just hate seeing threads degrade like this. Been guilty of that same energy myself at times.
Let's just all agree to disagree!
Tightening down with hand turns not over done is OK. Why we would be arguing about using the specified tq with a tq wrench spec is hard to understand. it's OK.
Using a little anti-seize to keep the plugs from seizing's due to some suggesting leaving the plugs in for a lifetime is OK.
Not using any anti-seize is also...OK.
Be careful that we don't go back and pull post that contradict, = just do what Lexus says, just do what the part manufacture says, then showing a 360 of things like the Trans threads, vs now saying don't do what they say do. For the Record not just b/c, .... including myself and other also. Everyone has their own way of being right but wrong, and/or wrong but right. If your Boat floats your way it Floats. Information wise, we should be documenting when to do, how to, things to be careful about, and useful info. Yes I have been known to do things the wrong way too. I just hate seeing threads degrade like this. Been guilty of that same energy myself at times.
Let's just all agree to disagree!
Last edited by jgscott; 05-02-23 at 06:44 PM. Reason: sp & grammer!
05-02-23, 11:31 AM
#41
Lexus Test Driver
12-26-23, 01:47 AM
#42
So with the discussion about fake spark plugs on other threads, is it possible that the Lexus dealer's supplier could be getting the fake ones and inadvertently selling the fake? How can you tell if you are buying from a dealer? Maybe they don't know that it is fake. Any thoughts?
12-26-23, 03:37 PM
#44
So with the discussion about fake spark plugs on other threads, is it possible that the Lexus dealer's supplier could be getting the fake ones and inadvertently selling the fake? How can you tell if you are buying from a dealer? Maybe they don't know that it is fake. Any thoughts?
02-03-24, 05:36 PM
#45
I bought some Denso plugs off of Amazon for my 09 ES350 at a cheap price, after around 30,000 miles, I had a misfire. I pulled the plug from the cylinder with the misfire and the electrode was gone, pulled another plug as it looked just as bad. No doubt I bought fake/counterfeit plugs from Amazon. Bought a replacement set from Rock Auto and no issues. I will not buy auto parts from Amazon again, buyer beware.
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JeffKeryk (02-03-24)