Bosch Plugs
 

Hello again all, I have seen several posts that mention NOT to use Bosch plugs in the 4.2. Could somebody tell me why?

Thanks in advance.

Short answer: They have a history of not working well in Ford trucks.

Why? I have no idea.

Wish I had more specifc info, but that pretty much sums it up. Stick w/ Motorcraft is my suggestion.

I ran a set of Bosch Platinum's in an 85 Bronco II with the little 2.8 I had 15 years ago. The things went to crap in 6 months.

Which bosch plugs are you thinking about running?

I've ran platnium +4's in 3 different vehicles including the truck I'm driving now and saw a noticeable improvement in performance. The first vehicle I had was a '91 300zx and my retarded@$$ didn't even have the #6 cylinder hooked up before I took it for a spin and it ran even better than before (It was really fun to drive when I had all 6 cylinders banging away;) Next I put them in a '94 f-150 with a v8 and and saw an improvement there too.
My truck gets really good gas mileage which I attribute to those spark plugs. It's 120 miles from the oil rig I work at to my house and I only use a quarter of a tank of gas =) sometimes less than that.

I guess for some people they work and some they don't. They've never disappointed me in my endeavors.

If you're not feeling lucky though just stick with the motorcraft/ auto lites or NKG.

I put a set of Bosch P-2's in a few months back (before joining this group) and wanted to make sure they were'nt gonna damage my engine, If it's just about drivability, I haven't had any problems yet....(knock on wood)

Ive used the +2's in my 99 w/ 4.2 for about two years and no problem as said above. Used it as a rig runner as well 300-400mi each way and many long distance trips. Still no problems.

I'm glad to see that someone else out there has had good experiences with bosch plugs =)

Me too actually.
Maybe they changed something in recent years that makes them more compatible with Ford trucks.
Regardless, glad to hear anytime someone has good luck with their truck!

The +2's are working really well in my 91 Ranger 4.0L ...picked the power up nicely.

I doubt that,unless your old plugs were so far gone they were making the engine lose power! :rolleyes:

I should post a photo of the electrodes :-missingt the edges of every plug are noticably rounded off.

when did yall change plugs?

I just pased 80k yesterday, gonna do my 5k oil change today (I use synthetic) I have done 'some' tune-up work on my truck, butnot plugs and wires, havent had a problem at all...basically...the only things on my truck that arent stock are brakes, tires, belt, waterpump, altenator...and the pcv? valve I think.....and just about every single body panel has been replaced at one point or another....including the entire bed and half the cab

Bosch Plugs
 

The reason you DO NOT USE BOSCH plugs in any motor is because if your motor is older and has a little blow-by the oil will cause the Bosch plug to explode and the ceramic material at the bottom will score your cylinder walls.I learned this the hard way.............Motor still runs but the blow-by now is so bad, you can't even drive it.

hahahahahahaha .......bull***** , not saying it did not happen TO YOU but many others here used Bosch plugs , a lot had problems with driveability and economy nothing permanent .

I agree 100%. Ive got the 4.6 in my mustang and only down side ive noticed with the bosch plugs is that after a few months they get pretty rough. Definetly likes the nkg's more.