Holden Servicing - spark plugs

[carcollector]

Doing a routine service on my V6 WM today - from the service records, it looks like all previous servicing has been done by a Holden Dealer. Imagine my surprise when I pull out the spark plugs to change them - I bought a set of NGK Platinum LTR6AP-11s, which are the standard specified plug, I believe - only to find that the plugs fitted to the car are a Bosch Super R6 - basically an old design, cheap copper based plug. I also found that the upper inlet manifold gasket had been broken, and had been glued together with sealant.

Just goes to show how far you can trust a Holden dealer, I suppose.

 

[davey g-force]

Lol that'd be right...

 

[showbags]

It's common practice for the inlet plenum to be resealed with sealant. As for the copper plugs, the previous owner probably had a heart attack at the price Holden charges for platinum plugs.

 

[RiCeY]

Upper gasket shouldnt be touched as the manifold doesnt need to be seperated in the first place.

A dealer would know this. Im guessing the owner attempted to do his own plugs as you have or the mechanics an idiot.

 

[carcollector]

Upper gasket shouldnt be touched as the manifold doesnt need to be seperated in the first place.

A dealer would know this. Im guessing the owner attempted to do his own plugs as you have or the mechanics an idiot.

Umm, the upper plenum has to be taken off to replace the rear plugs. The upper gasket seals the upper plenum and lower plenum, so it does have to be disturbed when the plugs are replaced. Were you thinking of the lower plenum gasket?

Also, the service book lists the (then) local Holden Dealer as doing the service where the plugs should have been changed.

 

[RiCeY]

What would i know Im only a Holden mechanic right?

The upper plenum does NOT have to be seperated from the lower plenum to do spark plugs. Ive done them more times than youve played with yourself (well probably not).

You lift the manifold up as one piece to gain access, it doesnt even need to be removed from the car.

 

[greenacc]

I'd love to get a copy of the actual service bill from that job and find out. It could even be a case of the apprentice picking up the wrong plugs and wacking them in not knowing the difference.

The question is how did the plugs look when they came out, and does it drive any better now ? Maybe someone knew something we don't, like those fancy plugs are all spin and no different from the old ones etc etc

 

[d.k.vmatt]

I think he means seperate the plenum from the runner section.That 100% has to be removed as there is no way in hell to get the coils out without removing it.

 

[m1lky]

I'd love to get a copy of the actual service bill from that job and find out. It could even be a case of the apprentice picking up the wrong plugs and wacking them in not knowing the difference.

The question is how did the plugs look when they came out, and does it drive any better now ? Maybe someone knew something we don't, like those fancy plugs are all spin and no different from the old ones etc etc

My understanding was that the major difference was the life. Platinum plugs are good for 80k whereas coppers are only good for 20

 

[carcollector]

Ricey, send us a photo of how you get the coilpacks off the rear plugs and then remove the plugs without undoing the upper plenum, and I'll believe you, OK? Then again, if it involves playing with yourself while you do it, I bow to your superior knowledge!

Greenacc, the plugs actually didn't look too bad as far as heat and fouling goes. The biggest difference with the older style copper plugs is that the copper electrode is larger, flatter and soft, and erodes with time. Sparks like a really nice small, sharp electrode to hit, which is why exotic metal plugs work better. Their centre electrode is coated with a noble metal such as platinum or iridium, which self cleans, and doesn't erode with time. That's why they've got such a long service life. Copper electrode plugs deteriorate more quickly, as they have a larger flatter centre electrode, and when the sharp edge wears off, sparks can be a bit erratic and the gap increases as the electrode erodes. As for improvements, well, I've only just replaced the plugs so I can't vouch for any vast improvement, but the car is a little sharper on mid range response.

m1lky, the V6 quotes a 120,000 km interval for replacement of plugs. Pretty impressive, when you consider what they have to do over that 120,000 km.

Cheers,