Spark plugs for V6 GR

[Mustang]

Can someone please advise on this. I was going to do a minor service on the car, -oil change filters plugs, etc. That was until I looked at the access to the rear cylinder bank! After that and having done some research, online, workshop/engine manuals, etc I would appreciate if someone could confirm a few things for me.
1.Front and rear bank plugs have different part numbers. From the research I have done, it seems to me that the difference is that the rear bank plugs simply are of a longer-life-design. Is this correct? Are all the plugs physically the same size? Plugs offered by funky product, etc, do not seem to differentiate between front and rear banks?
2.Looking at the parts list on this site the specified (mitsubishi/NGK) plugs are described as follows: MS851358 GR front; MS851347 GPX rear –are these also the recommended plugs for the GR rear bank–it’s not that clear!
3.Looking in the engine bay, there is a label that reads something like “please use our recommended plugs, with resistor”. Is this resistor an integral part of the plug or a separate item?
4.To replace the plugs on the rear bank, the inlet manifold (referred to in the manuals as the air intake plenum) has to be removed. As I understand it the inlet manifold gasket (air intake plenum gasket) should be replaced. This is the gasket with the six rings, mitsubishi part no. MD175776 (from funky product). Is this correct? Any other gaskets, items that need to be replaced, to change the rear plugs?

Thanks
Ross

[CJ]

1.Front and rear bank plugs have different part numbers. From the research I have done, it seems to me that the difference is that the rear bank plugs simply are of a longer-life-design. Is this correct? Are all the plugs physically the same size? Plugs offered by funky product, etc, do not seem to differentiate between front and rear banks?

Yep thats it, rear plugs are longer life, thats the only difference

2.Looking at the parts list on this site the specified (mitsubishi/NGK) plugs are described as follows: MS851358 GR front; MS851347 GPX rear –are these also the recommended plugs for the GR rear bank–it’s not that clear!

Yes, plugs on both V6 engines are the same

3.Looking in the engine bay, there is a label that reads something like “please use our recommended plugs, with resistor”. Is this resistor an integral part of the plug or a separate item?

Its part of the plug

4.To replace the plugs on the rear bank, the inlet manifold (referred to in the manuals as the air intake plenum) has to be removed. As I understand it the inlet manifold gasket (air intake plenum gasket) should be replaced. This is the gasket with the six rings, mitsubishi part no. MD175776 (from funky product). Is this correct? Any other gaskets, items that need to be replaced, to change the rear plugs?

No, all you need is the inlet manifold gasket.

CJ

[Mustang]

CJ your a star, thanks for the quick response. If I had rang 999 it probably would have taken longer to get a response
I think I'll get Paul Nolan to do the rear plugs, I think it's at the limits of my technical ability

[CJ]

Mustang, if you havn't already seen the Howto on Funky-fto.co.uk, check it out here.

CJ

[Daz]

The rear plugs thou longer life are also slightly different in design aswell the front plugs have one outer electrode and the rear will have two outer electrodes, this is due to the swish and swell rates in the respective cylinders.

Daz...

[steelroe]

Plugs for both 2.0L engines are not the same.

NGK for MIVEC are Front - BKR7EKC-N Back - PFR7M
NGK for Non MIVEC Front - BKR6E-11 Back - PFR6G-11


Just checked in the NGK catalogue

[ronbyrne]

i changed my plugs a while back and although i had a new gasket i didn,t need it, but before you start just change the front ones to get a feel, i didn,t like the feel of the spark plug spanner in the stock toolkit ( it felt like it could move to the side and break a plug) so buy a "DRAPER" long reach box spanner. i got mine in "motorway" in blanchardstown centre. it's a bit wide so you need to twist it left and right as it goes down to the plug, don't worry cos it's only a plastic sleeve, but when it engages the plug it's far more secure than the stock one, those plugs can be well tight. for tightening the new plugs i used the stock spanner as it didn't bind with the sleeve and you can feel for the 1/4 or 1/2 turn your plugs require

[Mustang]

All thanks for your help..much appreciated.

[Mustang]

Just a follow up on this...... I finally got around to replacing the rear plugs last weekend. The write up on Funky FTO (link above) is excellent, and the job really is a lot easier than you might think. If anyone is putting off doing this job because it looks like too much of an undertaking, then you really should reconsider!
I replaced the inlet manifold gasket, but the old one was not damaged and could have been reused.
The gasket seems to be made of a very hard material and to be honest I find it hard to image that the gasket would tear when removing the manifold.
Thanks again to all for the advice.

Mustang

[Myfeckin FTO]

For what its worth - I use Denso Iridium's all round - they are meant to last 60K miles - and give a few BHP increase to boot. In any case - there was a big difference over the old burnt plugs.

Denso iridiums = better spark,slightly better performance,longer life and better reliability.

If your serious about trying to extract any useful amount of extra BHP with mods like Induction kit,Chip(Good quality like Dastek),Cat free Exhaust with uprated manifold & downpipes then I'd certainly add Iridium plugs to this list.