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CAMEL74
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24 Posts
Beats me how ANY spark plug knows what country the engine came from.
I'm thinking that the person installing the plugs selected the wrong plug for his/her particular engine.
Experienced mechanics know that there is ALWAYS some monkey that wants to experiment with different heat ranges and/or plug reaches, thinking that they will improve performance -- then when it all goes to hell, they blame the plug manufacturer.

A couple of years ago, I was travelling in Idaho (speed limit=80) and got a "Check Engine" light.
My Actron OBD II scanner showed a misfire in #7 cylinder.
Pulled the plugs (Bosch), and they looked "bad" after only 40,000 miles. I had expected 100,000 miles, so I was pretty jacked at the plug failure !!
The mechanic was a young fellow, who said he had a lot of trouble with Bosch plugs in the same 4.6 liter FOMOCO engine.
He installed a set of Densos (at $7.60 each), which got me another 1,200 miles to get back home.
After arriving back home and investigating the situation, I discovered that I had ordered the WRONG part number for my application !!
Stupid mistake on MY part -- not a reflection on the Bosch plugs at all !
I yanked the Densos, and replaced 'em with Bosch plugs of the correct type and part number (Bosch 9605, Double Iridium). No more problems !!
Kept the Densos for spares -- ya never know !:>)
I don't have anything against Densos or NGKs, but I run a lot of Bosch parts on my '95 Mercury Grand Marquis Restoration -- Fuel Pump, In-Tank-Screen, Fuel Injectors, Plugs, Ignition Wires, Alternator, and Starter.
I use the Bosch fuel and ignition parts on the FOMOCO engine because FOMOCO uses an ignition/fuel-management system that was designed by Bosch -- similar to that used on Porche and Audi, and shared with a couple of million Ford Crown Vics, Mercury Grand Marquis, and Lincoln Town Cars.
The Bosch Fuel/Ignition system has proven to be extremely reliable over the decades, for domestic cars and Ford trucks used in fleet and police vehicles.
I don't tell others what they should buy or do -- I just tell 'em WHAT I DO, and WHY.
 

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19 Corolla HB SE 6-spd
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6,947 Posts
Scroll down further at rockauto.com:
BOSCH 9600 OE Fine Wire Double Iridium; Iridium; 0.043" Gap (Pre-gapped). @ $4.92 each.
Denso (or anybody else) does not offer a DOUBLE- IRIDIUM spark plug.
Just sayin' ;>)
Denso Iridium TT has an iridium center electrode where it counts. Its ground electrode is of Titanium-enhanced alloy... Titanium is arguably the most beautiful metal on the face of this planet, and of the most resilient as used to build interstellar spacecrafts! It is after all made in Japan :D

http://densott.com/
 

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CAMEL74
Joined
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24 Posts
Lots of very cool and extremely beautiful sights in Japan -- was there (courtesy of USNavy) back in 1956.
Mount Fuji is beautiful all year 'round -- as are the Japanese women !!
I wasn't paying much attention to their spark plugs :>)
 
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CAMEL74
Joined
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24 Posts
Denso Iridium TT has an iridium center electrode where it counts. Its ground electrode is of Titanium-enhanced alloy... Titanium is arguably the most beautiful metal on the face of this planet, and of the most resilient as used to build interstellar spacecrafts! It is after all made in Japan :D

http://densott.com/
Standard Pressed Steel (Jenkintown, Pennsylvania) was producing titanium aircraft fasteners as early as the late 1960s in their "HI-TI" division.
I have a nephew that still works at SPS.
 
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Registered
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51 Posts
I've found Bosch to be hit or miss. I had a Bosch water pump go bad in less than a year(about 4 years back). I had Bosch plugs foul multiple times in my Rx7. Installed NGK without issues for years. And they were the correct type plug in both cases.

Truth is, in all my years of being a mechanic, I've had plenty of Bosch failures and Zero Denso/NGK failures. I think the Bosch OEM stuff is very good, but find their aftermarket stuff falls short. As for Denso, I find little to no difference between their OEM and aftermarket lines, as they're both top tier.

:smile:



Beats me how ANY spark plug knows what country the engine came from.
I'm thinking that the person installing the plugs selected the wrong plug for his/her particular engine.
Experienced mechanics know that there is ALWAYS some monkey that wants to experiment with different heat ranges and/or plug reaches, thinking that they will improve performance -- then when it all goes to hell, they blame the plug manufacturer.

A couple of years ago, I was travelling in Idaho (speed limit=80) and got a "Check Engine" light.
My Actron OBD II scanner showed a misfire in #7 cylinder.
Pulled the plugs (Bosch), and they looked "bad" after only 40,000 miles. I had expected 100,000 miles, so I was pretty jacked at the plug failure !!
The mechanic was a young fellow, who said he had a lot of trouble with Bosch plugs in the same 4.6 liter FOMOCO engine.
He installed a set of Densos (at $7.60 each), which got me another 1,200 miles to get back home.
After arriving back home and investigating the situation, I discovered that I had ordered the WRONG part number for my application !!
Stupid mistake on MY part -- not a reflection on the Bosch plugs at all !
I yanked the Densos, and replaced 'em with Bosch plugs of the correct type and part number (Bosch 9605, Double Iridium). No more problems !!
Kept the Densos for spares -- ya never know !:>)
I don't have anything against Densos or NGKs, but I run a lot of Bosch parts on my '95 Mercury Grand Marquis Restoration -- Fuel Pump, In-Tank-Screen, Fuel Injectors, Plugs, Ignition Wires, Alternator, and Starter.
I use the Bosch fuel and ignition parts on the FOMOCO engine because FOMOCO uses an ignition/fuel-management system that was designed by Bosch -- similar to that used on Porche and Audi, and shared with a couple of million Ford Crown Vics, Mercury Grand Marquis, and Lincoln Town Cars.
The Bosch Fuel/Ignition system has proven to be extremely reliable over the decades, for domestic cars and Ford trucks used in fleet and police vehicles.
I don't tell others what they should buy or do -- I just tell 'em WHAT I DO, and WHY.
 

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straight cash homie
Joined
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21,918 Posts
You talk like there's a difference between Denso & NGK. There really is no difference. As far as running 91 over 87, 91 has much better/more cleaning additives.

At least where I've worked, Chevron Richmond refinery.:smile:
If employees get to fill up with 91 for the price of 87, why the hell not >:D
 

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Registered
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1,753 Posts
Discussion Starter · #31 · (Edited)
I wonder what Sydney decided to buy?.... Hopefully not Bosch! :)
I did not get a chance to remove a spark plug to examine condition and make & model of spark plug. From all of the reading I used to do for over 10 years on Toyota 4-Runner/pickup dedicated discussion sites (Toyota Nation and about 4 others) I learned that for a Toyota vehicle Denso and NGK were the best tune up parts specially spark plugs. So if or when I need spark plugs I will buy Denso and probably the Iridium TT which as people have stated here they are the exact ones in my car (1ZZFE engine).

Toyota # 90080-91184 (Denso SK16R11 Iridium)) is $14.95+tax at my local dealership and most dealerships in Canada



but I will buy Denso Iridium as it seems to be the best quality according to Rock Auto's info chart:

http://www.rockauto.com/en/moreinfo.php?pk=222818&cc=1432915&jsn=36

Just not sure which grade of Iridium I should buy?:

Denso # 3324=Iridium Long Life= Gap 0.044=CarQuest (local auto parts store)=Cannot get it
Denso # 4701=Iridium TT= Gap 0.040=CarQuest=$12.25+tax (15% HST local tax)
Denso # 5303=Iridium Power= Gap 0.044=CarQuest=$12.25+tax

To buy from Rock Auto there is a 25% or so exchange rate on USD to CDN Dollar as well Credit Cards charge 1.5% or so on top then $8.50 handling fee (used to be $5 ) and US Mail about $8-9 from Rock Auto. Again I have to see if my spark plugs are bad.

Keep the opinions coming, thank you.

Sidney
E-mail: sidneybek(at)yahoo.com
Dartmouth, Nova Scotia
Canada

2008 Toyota Corolla model: CE with 1.8L and 5 speed manual with 207 700 KM (made in Ontario, Canada in 2007)
 

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Premium Member
Joined
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14,785 Posts
No it won't, spark fires at the same time regardless and the difference in gap is 1/10th of a milimeter. A slightly smaller gap is fine since the spark is better exposed. The lower firing voltage needed to cross that gap is good since it'll stress the ignition system less. Detonation would maybe be a heat range issue, and the 4701 is the correct heat range for a 1ZZ-FE. Gap distance difference so small won't make a lick of difference, if anything they might wear out to .044 inch gap at the end of life in 150,000 miles. Anyway, the spec for gap is.....drumroll please....

Gap 1.0 - 1.3 mm (0.039 - 0.051 in)
So the 4701 is in spec, at the smaller end, which means as they wear away they'll still be in tolerance. I bet you could leave them in for 200,000 miles and when they come out they'd be in spec under 0.051 gap but pretty worn out looking. I know on my 2ZZ I noted a HUGE difference from 30K mile Iridium IX plugs and the Denso Iridium TT plugs, the idle was incredibly smooth with the new plugs and the engine felt a good deal smoother over all when driving.
 

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Super Moderator
2005 Corolla CE
Joined
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15,121 Posts
All of your Iridium plug options are already discussed in the maintenance thread:

http://www.toyotanation.com/forum/1...a-matrix-pontiac-vibe-maintenance-thread.html

The OEM installed 3324/SK20R11 Iridium Life are rated at 120K miles and shown to go much longer on a 1ZZFE with minimum gap increases. Also OEM are the NGK Laser Iridium 4996/IFR5A11/IFR5T11 which also show minimum gap increase at the OEM interval and are OEM on many 2000's era + Honda models.

The Iridium TT (4701) is the OEM plug on most newer Toyotas, especially those with Direct Injection. It has a slightly reduced interval (100K) but it's smaller starting gap likely means you will be able to go much similar mileage as the above listed plugs with similar results.

Personally, I use the Iridium TT in everything I service now. It's well priced, widely available, has all good reviews, and lasts 100K miles.
 

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The Return of the Red Coupe
2010 RAV4 V6
Joined
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19,669 Posts
You're ok with either one... I usually do NGK on all my cars, and wait for the 20% off sale at either Canadian Tire or Parts Source (CT owned).

I just did the required Iridium plugs on my XRS... found out whoever did them last used Platinums instead, I mean they still work but are not what the 2ZZGE motors call for.

For the 1ZZFE motors you're ok with Platinums, But you can get Iridium at CT as well . The NGK site is usually pretty good for reference, will tell you which one to use... I think NGK only makes one grade of Iridium, the motor calls for one but the NGK site will point you to the next grade... maybe one is now discontinued.

Just wait until CT has their sale and pickup all 4, takes about 30minutes to change them.
 
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