Hey all

I just got done replacing my factory spark plugs and was a little surprised at the plugs ford put in there. The gapping on them was all jacked up. I didn't go as far as to measure the differences, but you can tell by just eye-balling them there was huge variances. I'm surprised that a few of them were even firing.

What brought this on: I was having an idling problem, so I thought I check my plugs - and that was definitly the problem. I replaced them with NGK IX iridium plugs and it made a HUGE difference. The truck couldn't be running any better.

I would certainly recomend checking your plugs no matter how new or old your truck is, because Ford apparently doesn't. Your vehicle will thank you for it.



bob

 

billybob,
Interesting...I was just considering doing my plugs and wondering if it was worth the effort (I remember all too well changing them on my '97...)

This would tend to sway me towards at least pulling one to have a look and see if my plugs are "overgapped" as well. Did you see this on all your plugs or just a few?

 

I would definetly check them.

Not all my plugs were bad. 2 were seriously over-gapped and 1 was undergapped. It just really caught me off guard that Ford would over look something like that.

 

I too have noticed this before. Many times I have gapped my plugs despite them being "pre-gapped" when they box them, just my insurance. Upon taking them out for replacement, they were always off from what I set them at. I think cylinder pressures and temperatures might contribute to the little tangs to move. I have seen this in many different cars from pocket rockets to american muscle cars to my GSXR 750, even my 2001 Ford F150. I have not tried the new iridium plugs yet, I might give them a try soon.

 

You may be right. That idea didn't cross my mind, but the more I think about it, it makes sense. I'll have to research this idea.

Thanks for the input

 

those iridium plugs added 2 hp (dyno proven) to my sportbike. too bad we need 8 of them for our trucks. (i only needed two for my bike- vtwin 1000cc sportbike)

 

billybob I take it you bought your truck new?

 

billybob, not saying your eyeball test was off but a Plug gap measurement tool is the only way to know for sure. As hcmq implies, maybe someone else (not ford) installed improperly gapped plugs?

 

yes, I did buy my truck new and I'm very particular about work being done on it. I've done most of the work myself (except for leaf springs) and I can assure you those plugs have never been pulled. As for the gapping variances, there was no tool needed. You could definetly tell. I hope I didn't throw them away. I'll see if I can find one and post a pic for ya

 

The plug gap can change due to heat, etc. I have seen this many times on my mustang.