[engineer76]

Hi Guys

About 3000 miles ago I did a tune up on my 2000 GT. The car is all stock as far as I know.
After driving it for a while I realized that at 4000 - 5000 rpm I sometime have engine pinging. Since I did not realize that before, I was wondering if that could have something to do with the Bosch Platinum +4 spark plugs that I droped in there.
I know for fact that the element platinum does a thermal reaction with exhaust gases (catalytic converter), that's why I thought it might be that the spark plug tips get to hot and pre ignite the mixture.

What's your experience with those plugs? Any advices? Let me know before I buy a set of Motorcraft and find out that I have the same problem...

Thanks in advance

 

[NoSlow5oh]

Even if changing the plugs to regular Motorcraft didn't fix the problem, I would do that anyways. I could tell a difference between the plugs and the simple plugs work the best.

 

[rick10]

Engineer76,

I have a 2000 Mustang GT also, and I get the same detonation noise in that rpm range at wide open throttle (WOT), on 87 octane. It goes away with 89 octane. I have the original plugs at 39000 miles. That is a bad sound at WOT, it can burn holes in your pistons. The PI heads with roughly a 10:1 compression ratio are right on the edge of 87 octane usage, some will take it, others won't.

But I have seen several supercharger suppliers recommend not to use the platinum plugs, others have had bad experiences with platinum. Not sure why.

 

[dollarbill]

I used to have the Bosch Platinum +4s also. Many people said they could cause the car to run funny. I did develop a slight miss at idle, so I replaced them with Ford Motorcraft Platinums. They looked fine when I pulled them, but one side (1 prong) would be slightly darker than the other. I'm still not exactly sure if that was the problem or not, because I was going to put the stock coil packs back on also and see how it ran.

 

[ran260gt]

I was on the highway the other day and the temp was almost 100, and I opened her up a little ,from 80 to 100+ and , I could here the same thing as you , I think it was the heat that made it do it, because thats the only time its happened:shrug ! 87 octane is what my stang drinks !

 

[engineer76]

Thanks a lot guys.
I think I am just going to replace the plugs with Motorcraft ones.

Thanks for your info.

 

[rick10]

Ran 360GT,

I would recommend 89 octane and that noise should go away. Detonation is more likely to occur on a hot day, due to the hotter air entering the engine. You might be on the ragged edge, and only need 89 in the summer.

Your stock times are impressive. My best 1/8th mile time is 9.5 seconds at 76 mph with my 00 Convertible GT. I have a 3.73 axle and street tires, which resulted in a lot of tire spin.