2.5 Spark Plug Change

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CliveC
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2.5 Spark Plug Change

Postby CliveC » Tue May 28, 2013 10:16 pm

I have a 2002 2.5 Sport which at 99,700 miles has not had the spark plugs changed. So, this is my next job and would value some guidance as I understand that the plugs can break when trying to extract.
Should I soak them in WD40 or similar to help extraction? Any help would be much appreciated.
Also what plugs are recommended, I thought of Denso Iridium?

CliveC

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J44EAG

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Re: 2.5 Spark Plug Change

Postby J44EAG » Wed May 29, 2013 1:38 am

Soaking with a penitrator can only but relieve the possibility of breakage, Clive.

Unless rampant corrosion is evident externally, you probably won"t have an issue with extraction. Such issues have not been a known problem to us in the past.

Suggest you replace the two small and cheap rubber air breather elbows when you change the plugs. Parts only available from a Main Dealer. These elbows crush and split so a must do item whilst the inlet manifold is off. Unwise to miss the opportunity.

Use the Vin number to select the correct plugs for your car. Your supplier will be able to advise.

Hope that helps.

Mike
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2004 XJR

CliveC
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Re: 2.5 Spark Plug Change

Postby CliveC » Wed May 29, 2013 5:44 pm

Thanks Mike, will let you know how I get on but it will be a little while before I get to it.

Clive

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Re: 2.5 Spark Plug Change

Postby oldtimer » Wed May 29, 2013 6:21 pm

Hi Mike,
Taking the plugs out is one thing, what is the torque loading for fitting the new ones?
I understand that plugs no longer have copper washers just a conical face and hole to match, what lube do you suggest?
P

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J44EAG

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Re: 2.5 Spark Plug Change

Postby J44EAG » Wed May 29, 2013 7:32 pm

There seems to be quite a torque spread suggested on various sites. I can`t seem to get to the technical data pdf I used to access but one good looking site I visited suggests 11Lbs/ft.

On a spark plug tube box there is usually a small visual diagram. I recall on the last set I installed that the taper seat plug is screwed down finger tight, then tightened one eighth of 360 degrees. These plugs only need to be gently tightened into contact to provide a gas tight seal. They do not need to be graunched down using a three foot long wrench and a lump of old scaffolding pipe!!

A smear of anti-seize grease such as Copper Slip on the plug thread is good practice between dissimilar metals. That will help prevent galvanic action and seizure through corrosion at a later date.

Mike
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2004 XJR

oldtimer
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Re: 2.5 Spark Plug Change

Postby oldtimer » Wed May 29, 2013 8:35 pm

What No scaffolding bar - that's a shame
Thanks

jeff1954
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Re: 2.5 Spark Plug Change

Postby jeff1954 » Sat Jun 01, 2013 8:18 am

Do you have to remove the inlet manifold to change the plugs?

Jeff
S Type 2.7d SE Auto 2004 Now sold but still a lover of older Jags.

Previous Jaguars.
1967 3.8 S Type.
Series 1 XJ 4.2
Series 2 XJ 4.2

Gary220262
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Re: 2.5 Spark Plug Change

Postby Gary220262 » Sat Jun 01, 2013 12:49 pm

Dont worry about spark plugs Jeff, on your diesel you just have to rake out the dead ash and put some more coal on ! :lol: . Gary
GARY
2000 S TYPE 4.0 V8 (for upsetting the wife ! )

2005 Mercedes E270cdi Avantgarde (for commuting and towing caravan)

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J44EAG

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Re: 2.5 Spark Plug Change

Postby J44EAG » Sat Jun 01, 2013 5:17 pm

Yes, Jeff. The inlet manifold has to come off. Don`t forget top change the breather elbows at the same time.

Mike
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2004 XJR

jeff1954
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Re: 2.5 Spark Plug Change

Postby jeff1954 » Sun Jun 09, 2013 3:19 pm

Went to Blackpool Zoo the other weekend doing eighty most of the time and got 43.4 to the shovel full. :wink:

Jeff
S Type 2.7d SE Auto 2004 Now sold but still a lover of older Jags.

Previous Jaguars.
1967 3.8 S Type.
Series 1 XJ 4.2
Series 2 XJ 4.2

Gary220262
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Re: 2.5 Spark Plug Change

Postby Gary220262 » Sun Jun 09, 2013 6:11 pm

Jeff, 43.4 compared to my average of 21.2 ! might have to stop taking the pi'' and have a look at one these smokey things ! do they come with shovel provided ?. Gary
GARY
2000 S TYPE 4.0 V8 (for upsetting the wife ! )

2005 Mercedes E270cdi Avantgarde (for commuting and towing caravan)

Martec

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Re: 2.5 Spark Plug Change

Postby Martec » Mon Jun 10, 2013 7:32 pm

Just a small point on the plug change, when were the coils last replaced?

When I bought our 3 ltr I noticed a slight misfire at low revs and a boot full of throttle, particularly noticeable when going slowly up our steep entry to one of the garages. New plugs and coils cleared it.

Shame to take the manifold off twice.

Brian
MY2000 3ltr S type manual standard car with leather seats, cruise control and mistral blue metallic paint.

1961 3.8 MkII manual, Indigo blue, nolonger runs on LPG, everything else uprated


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