Hello guys. I've had Zex plugs in my car for about a year. I didn't notice any issues up untill the last week or so. The car started misfiring, backfiring, and cutting out. I swapped the plugs out this morning, and this is what I found. I took several pics, but this is the only one that's clear enough to see. The ceramic broke off and blocked the electrode. I was only firing 3 cylinders.




So for everyone who uses Zex plugs, watch out for this. Unfortunately, I've heard of this happening before, someone on the redline forums had the same thing happen. I'll let you guys know what Zex says about this.

 

let us know what they say. that happened in a year? maybe they reccommend changing them frequently or something we missed. i guess i'll check mine this weekend if its nice.

 

How often should you change them anyways? 3 mo's? 6 mos? every oil change?

 

i was just about to order a set too!

 

Besides the zex what is the next best plug to get please include a part number, i only have the stage 2 with gmpp exhaust

 

I just put these in, I will check them in a couple months and see how they are doing. I had the NGK's and they we're still ok after a year of use but from now on Im going to check my spark plugs every 6 months.

 

Next best are the NGK BKR7E copper plugs.

That Zex plug is f'ed up man. Something wasn't right.

Well it took a year for that to happen. How often do you beat on the car?
If you are a "spirited" driver then colder plugs won't last you a year.

 

I hope your motor is fine!

 

I ordered the NON-Resister NGK R5671A-8 today, 2 step cooler and copper.

 

I'm going to check in a couple months too. I don't think they will look like that.

I don't beat on my car though.

 

I change my autolites every oil change.

 

This isn't the first time that has happened with the zex plugs. They know about the problem, and I think they were or have revised the plugs, but not every shop with them on the shelf knows this.

 

where is the piece that broke off?

 

HMM,.... I dunno I've been running the NGK brke8ix plugs for ever and never had an issue with them, when I went to the copper plugs I started getting random knock under full boost on longer pulls, went back to iridiums and problem never came back.

 

This is what they look like new.

 

Yeah and I just installed mine like 2 hours ago lol. I too am trying to find out how often they should be replaced. I see I don't put out near as much power as the original poster so I SHOULD be fine.

 

These things can happen with any spark plug. Don't discredit Zex because one out of a million might fail at some point. I have run these in my ss/sc as well as my supercharged Silverado and never had an issue. This isn't to say they won't. But for the last 15 to 20 years that I've had "hot rod " vehicles AC's, Champion, Autolite, Accel, and etc., each manufacturer has all had an issue somewhere. For the ss/sc application the Zex seem to run the best for me.

 

yeah you should see what a 100 shot did to my autolites on my "other" car... putting ZEX plugs in there though soon for the 125 shot

 

thats because they are autolights

W3rd.

 

Wow, there was alot of responses fast! FIRST, I'm not bashing ZEX in ANY way!!! Please understand, I just want other members to be aware that this happend, so that they can watch for it on their cars. I just replaced them with NGK BKR7E's for the time being. I haven't had any issues with the plugs untill now, and the other 3 plugs looked fine.
I DON'T BEAT ON MY CAR, in fact, it's almost like "why do I have the power if I don't ever use it"? I baby my car every day to and from work, it's tuned safe with 0 KR. It very well may be that some of ZEX's first batch had an issue, I was one of the first few people to buy these for our cars. I will keep you guys informed about what ZEX says. Feel free to ask any more questions.

 

are you supposed to torque spark plugs? and if so, at what?

 

The saying I always heard was "hand tight and then a 1/2 turn." However, we can't fit our hands in there to hand tight them, so I used the socket untill I felt it tighten, and then another 1/2 turn. I don't know of any actual torque specs, so I just did this.

 

yeah do the same here...

 

15 ft/lbs

 

thats what I figured..... damnit now I gotta take my tq wrench off 125 lb/ft... lol