# Spark Plug Replacement



## Xtrailguy (Mar 9, 2006)

When should I be replacing the spark plugs on my 2.5L QR25de?
My dealer is telling me that I should be ok until 160,000km (roughly 100k miles).

That seems a little high to me.

Any thoughts? My biggest concern is that a plug could become seized. Anybody change their own plugs?

Thanks.


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## Xtrailguy (Mar 9, 2006)

I think I just found it in the manual. 105,000 miles or 169,000km.
Must be good plugs!


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## LEONGSTER (Apr 9, 2006)

I pulled mine at around 30,000km and they were clean as a whistle with no apparent wear. Checked the gap and it was to spec.

One of them was seized though - had to use some Kroil and a rachet to remove it - they are the narrow-type plugs.


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## Canada's Far East (Jun 15, 2005)

Xtrailguy said:


> When should I be replacing the spark plugs on my 2.5L QR25de?
> My dealer is telling me that I should be ok until 160,000km (roughly 100k miles).
> 
> That seems a little high to me.
> ...


I replaced the plugs in the 05 SE with the Iridium 1X plugs. Changing the plugs is a straight-forward process which takes very little time.

I ran the Iridiums for about 25K before I traded the 05. I took them out and replaced them with the OEMs. 

I now have the Iridium 1x in the 06 Bonavista and find them to be a very good plug.

Here's the "key" - each time I pull the plugs, I coat the threads with an "anti-seize" compound and have never had a problem in removing them. 

It's a good "preventive maintenance" idea to pull them for inspection from time to time and then re-coat them with the anti-seize compound.

A number of years ago, I broke a plug in an aluminum head engine and had to pull the head to get it out - a time consuming and worrying experience - - since then I've become a believer in anti-seize compound.

Cheers


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## LEONGSTER (Apr 9, 2006)

Canada's Far East said:


> I replaced the plugs in the 05 SE with the Iridium 1X plugs. Changing the plugs is a straight-forward process which takes very little time.
> 
> I ran the Iridiums for about 25K before I traded the 05. I took them out and replaced them with the OEMs.
> 
> ...


Indeed good advice Roger. I used copperslip, just a tiny dab. When I first pulled mine they were the factory fitted ones I believe.

Do the NGK iridiums really make a difference? I have used Bosch platinum plugs with good results, but the effects are only temporary as the platinum seemed to act as a catalyst for better combustion but performance fell off quickly with use...

Since you pull your plugs time to time, have you tried Indexing them for more consistent performance between cylinders.


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## Canada's Far East (Jun 15, 2005)

*Iridium Spark Plugs*



LEONGSTER said:


> Indeed good advice Roger. I used copperslip, just a tiny dab. When I first pulled mine they were the factory fitted ones I believe.
> 
> Do the NGK iridiums really make a difference? I have used Bosch platinum plugs with good results, but the effects are only temporary as the platinum seemed to act as a catalyst for better combustion but performance fell off quickly with use...
> 
> Since you pull your plugs time to time, have you tried Indexing them for more consistent performance between cylinders.


In a lot of my previous vehicles I have used the Bosch Platinum as well and always found them quite satisfactory.

Heard some good stuff about the Iridiums and decided to give them a try in the X-T.

Our Nissan dealers list 6 different plugs that are used in the QR25DE engine - in different Nissan vehicles. Here's a list (none of them are Iridium):

LZFR4AQP
LZFR5AQP
LZFR6AQP

LFR4A-11
LRF5A-11 (this is the OEM plug in the X-Trail)
LRF6A-11

My understanding is that these are really only 2 type of plugs, with the 4/5/6 numbers changing the heat range/temperature.

There is a conflict between my research on service life and that which the dealer states.

Info from the Internet suggests that a platinum plug, with a 0.8 mm diameter will give a service life expectancy of 100,000 kms. 

The platinum plugs are touted to give better "ignitability" over a nickel alloy or nickel alloy V-Grove by virtue of their smaller diameter centre electrode.

The Iridium (non IX) are touted to give a service life expectancy of 160,000 kms., with the same level of ignitability as the Platinum.

The Iridium IX plug has a 0.6 mm diameter centre electrode and is "advertised" to give even greater "ignitability" over the other 2. However, their life expectancy is only rated at 60,000 kms.

I have used the Iridium IX now for about 30,000K in total (same set in 2 X-Trails). I looked for any "differences" when I first did the change over. It "seems" to me that the X-T would fire quicker (start), idle better (around 750 rpm) and "seemed" more responsive. But that is an unscientific and perhaps somewhat subjective assessment.

When I change or check the plugs, I have always replaced them in the same cylinder location. BTW, last time I looked at the plugs they were in "like-new" condition.

The OEM plugs from the dealer would cost me $6.83 Cdn. each. I got the Iridium IX from Auto Parts Warehouse in Garden Grove, CA (USA) delivered to my door for $8.69 Cdn. each.

For the price difference, limited amount of time required to do the change and the "potential" of more "fire-in-the-hole" I figured it was worthy of a try.

BTW - I did reset the ECU after the change over.

Hope this answers your questions and may be of some help to other members as well.

Cheers = Roger


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## Xtrailguy (Mar 9, 2006)

Canada's Far East said:


> The OEM plugs from the dealer would cost me $6.83 Cdn. each.


That is interesting Roger. I called our dealer yesterday and the guy told me that they would be $17 - $18 per plug! I called them at the 80k mark and they told me that the plugs would need replacement at 100k. Now at 105k, they are telling me 160k. I wish they would get their story straight. 

Thanks for the info. I might have a look at the plugs on the weekend.


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## LEONGSTER (Apr 9, 2006)

Thanks for the useful info, Roger. 

The price you paid for the Iridium plugs is a steal. They cost around 18 USD in Singapore!


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## ERBell (Aug 7, 2005)

Just remember a couple of things when changing your plugs. Most high end plugs with platnum or irridium cores come pre gapped. Also wait for the engine to cool down before replacing spark plugs on a car with an aluminum head(s)


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## bas (Oct 12, 2005)

Is it possible to get extra 'torque' or power out of the exy by going a colder or hotter spark plug (ie LFR4A or LFR6A). I have recently noticed that my exy is struggling a little to get up hills it was previously killing. I already have the Iridium LFR5A-11 plugs and they appear in good order.


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## flynn (Jun 23, 2006)

bas said:


> Is it possible to get extra 'torque' or power out of the exy by going a colder or hotter spark plug (ie LFR4A or LFR6A).


Normally you'd consider fitting hotter plugs if they were fouling and cooler if they were overheating and causing preignition. If either happened you'd want to know the reason first. Being down on power could be a lot of things. Doing a compression test might be worthwhile to start with.


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## SCHESBH (May 25, 2004)

*NGK Iridium*

Well I finally changed my Spark Plugs although Nissan said that I did not have to for many more miles...anyways I purchased from the same supplier as Roger my NGK Iridiums. So I set out and removed the fuses for the ECU...very easy as per the Australian Forum guides... Did a clean on my very dirty K&N filter... let it dry overnight... and applied the oil to a very now clean filter... removed and replaced my old Platinum Spark Plugs, again very easy and while looking at them they were in good condition.

Replaced everything... started her up and wow! Lower idle RPM's and smoother ride and acceleration... I am glad to have done this.

Now I will fill the tank and check the mileage!

Stephen


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## Xtrailguy (Mar 9, 2006)

How many km on yours Stephen?


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## SCHESBH (May 25, 2004)

*KM*

Not many.. in fact Marc and I always compare to each other and we are nearly the same! 48,500km .... three years old...I am not doing nearly the mileage that I used to do on my Altima.

Stephen


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## Canada's Far East (Jun 15, 2005)

SCHESBH said:


> Replaced everything... started her up and wow! Lower idle RPM's and smoother ride and acceleration... I am glad to have done this.Stephen


*IF* I were the type to say "I told you so" - then I guess this would be the time/place.

But I'm not that type  so I won't  

Good on ya - enjoy the smoother ride.

Cheers = Roger


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## plooms (Oct 28, 2009)

Just about to replace my plugs in a 2001 Xtrail just with the standard NGK plugs. I was wondering what should the gap be set to?


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## Stealth2424 (Feb 13, 2007)

plooms said:


> Just about to replace my plugs in a 2001 Xtrail just with the standard NGK plugs. I was wondering what should the gap be set to?


I just changed mine yesterday and from what i found the gap in mm is 1.0 - 1.1 mm..... Piece of cake job- shouldn t take more than 15-20 min.


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## gpieon (Jun 10, 2008)

Just popped in a set of NGK Iridiums @ 0.44. Not really impressed at this point in time. The stock NGK's were at 0.39. Nissan wants less than 0.44 and NGK specs 0.44

What plug gap is working for everyone else on Iridium IX?


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## aussietrail (Sep 24, 2004)

gpieon said:


> Just popped in a set of NGK Iridiums @ 0.44. Not really impressed at this point in time. The stock NGK's were at 0.39. Nissan wants less than 0.44 and NGK specs 0.44
> 
> What plug gap is working for everyone else on Iridium IX?


The standard NGK Plugs are rated at 1.0 - 1.1 (0.039 - 0.043) gap.

The NGK Iridium IX are 1.1


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## ohsobrown (Feb 19, 2015)

I'm having a seriously hard time figuring out what kind of special socket you need to remove the spark plugs that came in my 05 xtrail. 
I've ordered 3 different thin walled sockets and non of them work.

Can anyone advice me how to get these ridiculous plugs out? 
I've called 3 dealerships and they claim the 5/8th socket works. 
At this point I want to head but these techs on the nose.


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## quadraria10 (Jul 6, 2010)

I think your problem is that they have been in there since 2005. Here is a good link that explains the situation and tells you what to do
How to Remove Stuck Spark Plugs - AutoRepair.Answers.com.
Good luck with it.


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## otomodo (May 23, 2008)

5/8" work fine, the long ones.
The short socket wont take the plug out. By the way, do it with the engine cold, the rubber in the socket won t expand.


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## ohsobrown (Feb 19, 2015)

Thanks for you input but I don't think you understood my problem.
5/8 socket does not fit on the plug. The area around the tube and the spark plug is so thin that you can't actually get a socket to get onto the spark plug.


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## quadraria10 (Jul 6, 2010)

ohsobrown, you wouldn't be shi**ing us would you? Otomodo is absolutely correct. I have a 5/8 sparkplug socket as well that I have used to change my plugs. Its a longer one that is 2.5 inches in length. Either you are using a standard length socket or your extension is not long enough to get down to the plug.
Here is a link with a picture if you need one 
Ratchets, Sockets & Wrenches | Sockets-Hand | Craftsman® Industrial™ 9-23295 5/8" Spark Plug Socket 3/8" Drive | B668873 - GlobalIndustrial.ca


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## ohsobrown (Feb 19, 2015)

I'm dead serious. I have the 5/8th spark plug socket and it does not fit onto the spark plug.
I just had another mechanic over looking at it and he doesn't understand how any of his spark plug sockets won't fit onto the spark plug either.


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## quadraria10 (Jul 6, 2010)

Well sorry to hear that. I am assuming you have replacement plugs that do fit your socket?There must be crud build up over the end of the plug. Are all 4 like that? Unless someone forced a wrong sized plug down in there at some point, I don't see what else it could be. Seems strange because the hole is pretty well covered in normal operation. Guess you will have to try power blaster and then position the spark plug socket properly over the plug and tapping it down with some force to get onto the plug. Let us know what happens. Good luck.


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## ohsobrown (Feb 19, 2015)

The dealership can't even figure out how these spark plugs got in there. 
There's zero space to fit a socket on them. 
Might have to remove the heads and have a machine shop work on it.


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## chadn (Jan 28, 2010)

maybe the nut portion of the sparkplug isn't a standard size? For example, if it's a 16 or 17mm nut, the 5/8 socket won't fit on it. Might also need thin walled sockets. They got in there somehow.

I wonder if a standard deep socket is even long enough? Do you have a new spark plug to see if a standard deep socket works on it?


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## ohsobrown (Feb 19, 2015)

Does anyone know how to remove the spark plug tubes?


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