How often do you replace your iridium spark plugs? Nippon Denso recommends 30K miles - Toyota Nation Forum : Toyota Car and Truck Forums
8th Generation (1998-2002) Specific discussion of the 8th generation

 
LinkBack Thread Tools Display Modes
#1 Old 03-18-2010, 05:11 PM
New TN User
 
Join Date: Jan 2010
Location: New York, NY
Posts: 28
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 19
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
(Thread Starter)
Question How often do you replace your iridium spark plugs? Nippon Denso recommends 30K miles

for Iridium power plugs. From the Nippon Denso website:
Quote:
Iridium use represents the most significant technological advance in automotive spark plug manufacturing, since platinum was introduced in the early eighties. As vehicle manufacturers produce increasingly complex and efficient automobiles, there is a greater need for long-life plugs that can tolerate leaner fuel mixtures and improved combustion processes. DENSO has responded to this need by developing its Iridium alloy, originally for OE applications. For example, many newer Lexus’ and Toyota models carry an ultra long-life Iridium plug variation (.7mm with platinum tipped ground) that is capable of up to 120,000 miles of service. DENSO Iridium Power plugs, with their .4mm center electrode, have been developed for performance applications. Because gradual wear will “round-off” firing points over time, the concentrated firing power and voltage requirement benefits will be reduced. For this reason, DENSO advises replacement after 30,000 miles.
It appears that not all iridium plugs are created equal.
Mithridates is offline  
Sponsored Links
Advertisement
 
#2 Old 03-19-2010, 10:16 PM
Vivir el momento
 
Join Date: Dec 2002
Location: Toronto
Posts: 18,703
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Thanks: 8
Thanked 2,393 Times in 1,515 Posts
iTrader Score: 5 reviews
Stick to recommended intervals.

I replaced my old Denso Iridiums at 30K, just as recommended.
PhatRoyale is offline  
The Following User Says Thank You to PhatRoyale For This Useful Post:
Mithridates (03-22-2010)
#3 Old 03-21-2010, 01:10 PM
Owner of much Obsolete
 
Jeff Lange's Avatar
 
Join Date: Oct 2005
Location: Calgary, Canada
Posts: 2,269
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 6
Thanked 137 Times in 95 Posts
iTrader Score: 0 reviews
Denso S/F series Iridiums (the 0.7mm OE style ones) have the long lifetime change interval.
Denso I series Iridium Power (the 0.4mm style ones) have a much shorter change interval.

What change interval you use will depend on what type of plugs you have.

Toyota recommends 120k miles for all stock iridium plugs (SK16R11 for the 1ZZ-FE). If you are using SK16R11, I don't see any need to change them early.

If you are using Denso IK16's or IK20's or similar, then change them at Denso's 30k mile recommendation.

What type of iridium plugs are you running Mithridates?

Jeff


2011 Lexus IS250 Obsidian "F-Sport 6MT" with LSD
1986 AE86 Corolla GT-S Supercharged
Jeff Lange is offline  
The Following User Says Thank You to Jeff Lange For This Useful Post:
Mithridates (03-22-2010)
#4 Old 03-22-2010, 01:52 PM
New TN User
 
Join Date: Jan 2010
Location: New York, NY
Posts: 28
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 19
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
(Thread Starter)
Quote:
Originally Posted by Jeff Lange View Post
Denso S/F series Iridiums (the 0.7mm OE style ones) have the long lifetime change interval.
Denso I series Iridium Power (the 0.4mm style ones) have a much shorter change interval.

What change interval you use will depend on what type of plugs you have.

Toyota recommends 120k miles for all stock iridium plugs (SK16R11 for the 1ZZ-FE). If you are using SK16R11, I don't see any need to change them early.

If you are using Denso IK16's or IK20's or similar, then change them at Denso's 30k mile recommendation.

What type of iridium plugs are you running Mithridates?

Jeff
I think my plugs are the original plugs. I'm the third owner of the car, and at 80K miles, I'm starting to think about replacing them.
Mithridates is offline  
#5 Old 03-22-2010, 01:57 PM
Gearhead
 
Join Date: Jul 2004
Location: Northern Virginia
Posts: 1,993
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 14 Post(s)
Thanks: 10
Thanked 213 Times in 195 Posts
iTrader Score: 0 reviews
Doesn't hurt to replace them earlier - depending on the driving conditions/maintenance of the car - 80K-90K might be the limit for the OEM plugs.

Best not to guess - just pull the plugs and read the end. On my car - 90K-100K was all I was able to get before significant wear on the plugs started to affect performance.

2002 Toyota Corolla S, 1.8L 1ZZ-FE VVT-i
2003 Toyota Matrix XRS, 1.8L 2ZZ-GE, VVTL-i (RIP)
2009 Toyota Matrix XRS, 2.4L 2AZ-FE VVT-i
2009 Toyota RAV4 Limited, 2.5L 2AR-FE Dual VVT-i
fishexpo101 is offline  
The Following User Says Thank You to fishexpo101 For This Useful Post:
Mithridates (03-22-2010)
#6 Old 03-22-2010, 02:57 PM
New TN User
 
Join Date: Jan 2010
Location: New York, NY
Posts: 28
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 19
Thanked 0 Times in 0 Posts
iTrader Score: 0 reviews
(Thread Starter)
Quote:
Originally Posted by fishexpo101 View Post
Best not to guess - just pull the plugs and read the end. On my car - 90K-100K was all I was able to get before significant wear on the plugs started to affect performance.
What performance issues did you encounter that you decided the plugs had to go?
Mithridates is offline  
#7 Old 03-22-2010, 02:57 PM
FMVSS 108 FTW
 
AlaricD's Avatar
 
Join Date: Oct 2009
Location: Stillwater, OK
Posts: 639
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 26
Thanked 62 Times in 58 Posts
iTrader Score: 0 reviews
A mechanic I go to from time to time recommends replacing spark plugs at 30K so that a) you can read them to see if there's a problem and b) so that they haven't seized by 100K (he says that even with anti-sieze compounds there's a chance they'll seize if left in for that long).

As cheap as spark plugs are and as easy it is to do, is it really worth it to wait for 100K?


AlaricD is offline  
#8 Old 03-23-2010, 06:27 PM
Official TN Member
 
Join Date: Nov 2009
Location: GTA
Posts: 153
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 1 Time in 1 Post
iTrader Score: 0 reviews
How would one check if their spark plugs are worn and need replacing? im not sure when the previous owner changed them, so i would like to check for myself?
azncapcom is offline  
#9 Old 03-23-2010, 08:53 PM
New TN User
 
Join Date: Feb 2010
Location: Asheville NC
Posts: 12
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 5 Times in 2 Posts
iTrader Score: 0 reviews
The 1ZZ's tendency to blow by oil is a key factor to look at with spark plug intervals. Say at 130K miles you find a notable amount of oil loss, with no signs of leaks, when changing the oil. At that point, its really impossible to say when the problem began, because it certainly did not start after your last scheduled oil change, it only became apparent. If an engine is burning oil, it is contaminating plugs. Built forged forced induction motors constantly go through plugs for a reason, the engines are built with a slightly oversized cylinder wall diameter to allow thermal expansion to take place with the new forged piston, thus allowing more than normal oil blow by. Me personally, I change plugs the first time a 60K, then 100K, 130K, 160K etc. Shorter and shorter intervals to monitor the condition of the motor at the onset of higher mileage and to help keep fresh plugs in as the engine begins to use them up faster.

Beyond that, in normal compression, NA motors I never use iridium plugs. I haven't noticed a difference and they're a waste of money, especially when I keep up maintenance as I do. They have a place and are useful, just not in average motor applications.

Erotomania is offline  
#10 Old 03-23-2010, 09:48 PM
FMVSS 108 FTW
 
AlaricD's Avatar
 
Join Date: Oct 2009
Location: Stillwater, OK
Posts: 639
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 26
Thanked 62 Times in 58 Posts
iTrader Score: 0 reviews
Quote:
Originally Posted by azncapcom View Post
How would one check if their spark plugs are worn and need replacing?
Here's how to read a spark plug.


AlaricD is offline  
Sponsored Links
Advertisement
 
Reply

  Toyota Nation Forum : Toyota Car and Truck Forums > Toyota Passenger and Sports Car Forums > Corolla and Matrix Forum > 8th Generation (1998-2002)

Bookmarks

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome