These are the spark plugs I pulled - do they look bad? Some are pretty caked and I had a misfire code in one cylinder - kept getting a code. I should have marked which plug came from which cylinder, but I’m going to get new plugs. It could have been stuff from before I started to change oil myself about every 6 months, used 91 octane fuel, ran seafoam fuel injector cleaner, cleaned throttle body, cleaned MAF/air intake, installed new air filters regularly, etc.

It looks like after I’m done with the front cover/sump, I’ll have to remove the upper intake manifold to install new coil packs, wire and plugs.


I think I’ll try the STI wires (about $55), Bosch coil packs, and Bosch Double Iridium plugs.

Any input is welcome

 

Plugs have to be/are highly suggested to be Champion RC11PYPB4 from the technical training video and manual. For wires I really like Denso regardless of application

 

dont forget to 'Gap'them beore you install the new ones as the gap on you old ones look big

 

The training manual is decades old at this point. Newer plugs have been developed.
There are dozens of threads on this forum about plug recommendations. Try browsing a couple of them to see what experiences people have had. I believe that copper plugs have shown a tendency to develop misfires very quickly.

 

You don't gap certain plug types.

Sure but the control computer and ignition system hasn't changed and it expects a certain resistance and response from the plugs. Maybe it doesn't matter on this but on a GM waste spark system if you put the wrong plugs in the coil can't fire in correct time.

 

Many if not most modern plugs this is the case.

That's not an issue with these systems, though plain old copper plugs will wear out very quickly.

 

I historically wouldn't use Bosch plugs even if they were free. I don't remember why, but I remember feeling like I had a good reason. I know a few other people who also avoid Bosch plugs like the plague.

NGK is my go to in everything.

Champion, Sensor, even Autolites are fine, really. I will say, you don't need to spring for the iridium's. Platinum will treat you just fine for a long long time. Just stay a step above copper. The spark system in these isn't advanced enough to require anything more than platinum.

 

Good to know but factory uses double platinum anyway so I don't see why anyone would use copper? I generally use exactly what the factory does unless it's my super/turbo cars, the super gets a totally different plug style and the TT car gets 1 step colder but both are 600hp+ cars that eat plugs anyway...

 

My favorite plugs so far are NGK V-Power (notched nickle center electrode with copper core). Followed by Autolite Double Platinum for my Disco V-8s. Super reliable and don't break the bank. NGK wires are also excellent.

 

I wouldn't even put Champion plugs in a leaf blower. Terrible things. NGK are far superior. Agree that iridium are overkill for the Disco.