Anyone running Bosch Platinum plugs, what part # do you have for the plugs?

[scott.475]

Guys, I decided to cahnge my spark plugs to see if I could eliminate the pinging I have. I've been running the Bosch Platinums and they do not have a lot of miles on them. When I pulled them out it was clear they were running too hot. They were very clean and white. I though I had maybe gotten some that had a longer electrode to run hotter, so I took one to Schuck's to make sure. When I asked for the Bosch Platinum replacement plug it showed the same part number I already had, #HR8DPX. I decided to go with standard Autolite plugs to see if they ran cooler. When I got home I compared the two, and the electrode on the Bosch is easily twice as long as on the Autolite. I got them all switched out and the engine immediately ran smoother, not that it run too rough before. I then took it and run it up a long, paved hill that always causes the engine to lag and ping like crazy. It ran smooth and more responsively, no pinging at all. I am so happy.

Still, I really like Bosch products and am wondering what the heck is going on with them. What is the part # that any of you are running in your 4.0 engines, and are you experiencing any of the same problems I was?

I had also bought some Borg-Warner replacement wires, but its running so good now I don't know if I need to!

 

[eXplorerbubb]

i got mine at autozone. it is part #6241 according to autozone's website.

 

[Critical_Level2]

I have heard bosch plugs do not work very well in the 4.0 motors. I was told the bosch have a tendancy to run too hot for ford motors. I just got autolite double plats and they work great.

 

[eXplorerbubb]

i sure hope they work good! they were a pain to put in!

 

[scott.475]

Bubb, get a "stubby, flex handle" socket, and it makes it muuuch easier, given the tight spaces...

 

[Rhett]

I can only recommend Motorcraft plugs in a 4.0 OHV. Not Bosch, Not Autolite.

I like Bosch, I have used them in Buicks, VW, and Mazdas with good results. BUT I have not had much success with them in my (Ford) trucks. They didn't run too bad in the 2.9L (Bronco II) but in the 4.0 my truck was prone to pinging. Autolites made it ping too.

With Motorcraft plugs, I have not had this problem. I use the exact plug called for in the manual (AWSF-PP) which is a double platinum motorcraft spark plug. Gapped to .054". I have experimented with a larger gap (up to .062") but it seemed to make little difference.

 

[Anthon]

I had replaced mine a few years back with the Bosch Platinum, and my X ran rougher than I have ever seen it. I returned the plugs and replaced with the Motorcraft and it worked wonders. I would say it is a given not to use the Bosch Platinums in the 4.0