New plugs and leads - EASY

[glenhendry]

This morning I put in 8 new plugs and leads. I thought that it was going to be a really finicky job and I was not looking forward to it, but the whole thing was done in 1.5 hours and it was no trouble. It revs a little quicker and smoother, but my old plugs didnt look too bad and so I wasnt expecting a major improvement. See pics, They have been in for the 12 months I have had the car, through a few O2 and MAF problems, yet they looked ok. Does the black colour look normal?

I also put a new tie rod end in the steering arm, and the steering has tightened up nicely.

[33chinacars]

Is that new/old together in middle picture. If so washers look different. Flat washer on old plug & tapered washer on new plug. Then one of them is wrong I think :wasntme:

Gary

[glenhendry]

They are old vs new. I certainly that the new washer type is suitable, I stipulated that I needed them for a 2000 4.6 HSE. Anybody got the low down on this?

Thanks for your thoughts.

[PhilipA]

IMHO the old plugs show much too rich for an O2 car.

The plugs from my 3.9 14CUX with 02 sensors are MUCH whiter than those, and I would expect a Thor to be even leaner.

BUT it depends what sort of a run the car did before you changed them.

If you just moved it out of the garage or did a short trip they could easily look like that.
The difference in washers IMHO is that some are flat/used and the new ones are new and uncompressed.
Regards Philip A

[p38oncoils]

This morning I put in 8 new plugs and leads. I thought that it was going to be a really finicky job and I was not looking forward to it, but the whole thing was done in 1.5 hours and it was no trouble. It revs a little quicker and smoother, but my old plugs didnt look too bad and so I wasnt expecting a major improvement. See pics, They have been in for the 12 months I have had the car, through a few O2 and MAF problems, yet they looked ok. Does the black colour look normal?

I also put a new tie rod end in the steering arm, and the steering has tightened up nicely.

Hi Glen, following is a link to NGK Spark Plugs on how to read coloration and condition of plugs. NGK Spark Plugs USA (http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp) In my opinion all the plugs except the one on the end on the picture with the four plugs show fairly normal mixture, the one on the end indicates a slightly rich mixture.

[philmoon]

Hi Glen I did mine with bosch ones the other week ( motronic engine 4.6)
When I purchsed the damn things I remember thinking almost every car I have had is gapped at .8mm (yes they were the right ones from the list)
Put them in the car, car ran fine but something in the back of my mind was bugging me .... Next time I opened the bonnet I saw what it was..... A little sticker saying the spark plug gap is to be .95 - 1.05 so decided to pull plugs and investigate. black almost all over over with just a bit brown where the front of plug was (biggest area for spark).
So regapped and noticable difference while in low revs. No difference idle (smooth).
So you plugs look pretty good to me.
PhillipA I could be wrong here but I do remember reading that one of the main changes from going from lucas to bosch was the fact that the enginge didnt run lean, infact runs slightly richer due to all the overheating issues the gems had (this also shows in the power curve very little flat spot but overall slightly less power.)
Now before you jump up and down on me, Im not saying all overheating issues are running lean infact most i have read about are purely the radiator has no fluid (oops)
Just telling you what I have have read :)
p.s if you find letters missing in this answer its because my son decided to fix the keyboard (you got to love a 2 year old with a screwdriver lol)

[Keithy P38]

Explains why the bosch motors had less power but more torque than the gems ones...

[redandy3575]

Just a general question with plugs. How long do the normal spark plugs last compared to the iridium ones? And are the iridium's worth the pennies?

[p38oncoils]

Just a general question with plugs. How long do the normal spark plugs last compared to the iridium ones? And are the iridium's worth the pennies?

My experience is that with an engine in good condition normal plugs last roughly 40000 - 60000 kilometres but need to be re gapped every 15000 - 20000 kilometres. If one wants to maintain optimum gap all the time then one needs to re gap the plugs roughly every 10000 kilometres. Are iridium plugs worth the money, well that depends on the individual and how capable or active he or she is or whether he or she wants to fit and forget. Convenience comes at a price.

[clubagreenie]

Going back to the washers, while there are different types on some these look like collapsable/crush washers. "Single" use.

[Tombie]

Just a general question with plugs. How long do the normal spark plugs last compared to the iridium ones? And are the iridium's worth the pennies?

Better flame propagation, cleaner plug... Yep worth the money.

Were brilliant in my stroker motor, far better than std type plugs...

[adm333]

I tried several different types of plugs over the time, including normal plugs at about $5 a pop to NGK Iridiums at around $18 a plug.

However, in the end I settled on the Bosch Platinum which cost around $28 for 4 at SCA. These seemed to perform very well and last somewhere in between the regular plugs and Iridiums.

I also had LPG so I was prone to changing them more frequently anyway.

Dave

[Marshall]

However, in the end I settled on the Bosch Platinum which cost around $28 for 4 at SCA. These seemed to perform very well and last somewhere in between the regular plugs and Iridiums.

Dave

x2

http://www.aulro.com/afvb/p38a-range-rover/112556-spark-plugs-oil.html

[redandy3575]

The iridium plugs arrived today, and fitted this afternoon. WOW.......:eek: what a huge difference this makes.

Engine definitely runs smoother, and has a much more even power band across the entire rev range, where's before it had a bit of a flat spot around the 2000rpm mark. Power in general, engine response & economy is also up.

I noticed too that the engine burns the fuel more cleanely, as the exhaust doesn't smell as rich.

So far i'd say it was definitely worth the money.....