Seems like i get about 7k miles or so, before the electorde is pretty rounded, and has shrunk a little bit. Also, i'd like to know the mods and what type of plugs you guys run. CJ

 

Ya, 10,000 miles is about all that you can expect out of your plugs if you want to get maximum performance out of your car! They will run longer, but it will cause carbon buildup and we all know what that leads too!!! But by the way you describe them they need to be replaced now!!! Don`t forget to use anti sieze on the treads, if you strip one it`s engine teardown time!!!

HUMMER

 

Im glad im not the only one. I clean my plugs on a weekly basis, and change them every third oil change, which is 7500-8500 miles. If I go any longer than that, I start losing power from worn out plugs.

These plugs have 8K miles on them.

 

Thats exactly what my plugs look like. I'm also glad to hear that everyone else gets about that milage out of them. CJ

 

When I bought my 86, I asked the guy how his maintenance record was. He said everything was changed according to the dealer. After I bought the car, I went and checked the plugs and the electrode was about the size of a pin.

I didn't mind though...the car was only $150 and I expect to run into problems.

 

I would like to hear from some people who have a close to stock engine. The plugs lasted much longer in my 89 which was almost stock. I had the car for 25K miles, and only changed the plugs once, and that was just after I got it.

 

My old car -'90 COnvertible- had polished & matched ports, intake cone, hi-flow cat, cat-back, and ECU (MD racing - if you ask you better have done a search first). The last guy who tuned it (John Zentnor builder of Brooks Weisblat's 3rd gen motor), recommended using the 3rd gen platinum plugs even on an NA. I left them in there for a little over 18 months/15,000 miles.

When I changed them, they were worn worse than the picture above, but the new ones didn't provide any extra power readable by the butt-dyno.

 

My 87 n/a is bone-stock from the intake to the downpipe. I'm running NGK plugs and wires and I put about 100 miles a day on it.

The last time I changed plugs was last summer (June-ish?) and the car is still running great with plenty of power, but I haven't checked the plugs since I put 'em in.

I've been curious about what they look like now that I've got about 20,000 on them. I'll pull a couple today and let you know.

 

I tell you I don't get enough miles out of them. My engine is stock and I have put about 45,000 miles on my car since I have had it. I am on my 3rd set of NGK plugs (I had some autolites for about a week). When the plugs get worn down starting problems (flooding) start to happen. I don't try and make them last. I would rather just replace the plugs then have starting problems.

 

Mods in sig...I change my plugs probably every 2-3 months. I don't have to, I just feel like I want to. I also change my fuel filter every year, for the hell'uv'it. I always take my plugs out when I do an oil change, and use a wire brush grinder wheel to grind the crap off the spark plug.

 

Here ya go. This is the trailing plug on the rear rotor after about 25K miles (a guess):

 

Could worn plugs be the cause of my gassy smelling exhaust and poor idle?

 

If the car is miss firing it very well could be plugs, or a weak coil, semi plugged fuel injector....lots of things. But plugs would be the first thing i'd try. CJ

 

If your leadings (lower) are erroding significantly faster than your trailings (top), you might want to consider running all 9's.&nbsp This would give you significantly more life in the leading plugs.

The NGK's were not designed to run more than 10k miles (realistically, more like 5k miles) of life.&nbsp A CDI box will help you use the spark plugs to the very ends, since gap doesn't affect the CDI as much as the stock ignition.



-Ted

 

My first guess would be that you're running rich. Bet your plugs are lookin' pretty black too.

 

You can get about 30-40K max on your plugs on most highway driving. At 40K, my leading plug were shot

 

the plugs will last over 10k if properly tuned. I had averaged that on my T2...properly tuned.

Anyway, I had just changed mine @ 6500 miles on my '90 vert. I had noticed wear, but not as much as the pics above. The plugs could be used again...not. I had changed them due to the fact I had to retune it for the 3rd time (new rebuilt engine, must tune properly).

So, yes average is 10k on NGK's