My 97 F150 has 74000 miles. This past Saturday, I changed the plugs from the originals to Bosch platinum +4's. Did an oil and filter change as well. (The only things that have changed recently.)

Today, I had been in and out of the truck several times and it was running perfectly fine. I was leaving a parking lot and stopped at an intersection, it felt as if thhe anti lock came on, it sure felt like it. It was wet, not really slick, it was snowing a little. I left the lot and pulled onto the main street and the truck was running so rough all the sudden, it felt like it was going to die climbing a slight grade.

I pulled over in another lot and got out, noticed the exhaust was very foul smelling and could see it was coming out like a pulse instead of smooth like usual. (it was cold so the exhaust was visible.)

It has continued to run this way the rest of the day and this evening. Any ideas? I have heard several ideas from people, such as the Bosch plugs are crap, probably broke a wire during the change over (they are a b**ch to get out!) egr valve clogged, timing gear jumped, broken plug, catalytic converter bad, O2 sensor bad......... Help. I am overwhelmed with 'expert' opinions from people that have no idea how to actually test for the problem. Thanks in advance for ANY help..

RKM

 

Make sure all the plug wires are seated on the plugs.

Bosch spark plugs are junk.FACT.

 

I did try that first. all seem to be on tight. I hate to spend the time to do the plugs again but will. The Bosch's have a money back guarantee, I think the place I bought them would refund me too. What plugs do work well? I never had any luck with Champion in any vehicle, those are out. I heard NGK works well in Fords..

 

we have lerned from the school of hard knocks that after about 50k miles or about 3 years to replace wires along with plugs.

 

Probally bad plug wires, 4.6's are noted for wires arcing & shorting out in the boot area. Buy the best set you can get----it'll pay off in the long run.

 

If it is the plug wires, is it just coincidence that this happened today, two days after the plugs being changed? What is a good set, Motorcraft, Belden Borg Warner? If I do change the wires and it still runs bad, where do I look next?

Are the Bosch plugs bad enough that I should just take them out when I change wires? Thanks... R.K.

 

I've had the Bosch +4's in my 5.4 for almost 2 years and 34,000 + miles and they seem fine. No better or worse then the MC's that came out. Other then the fact that the MC's gaps were HUGE when I replaced them at 65k, but the old plugs still 'looked' ok........

I have noticed that most of the complaints about the +4's come from 4.6 owners........

I'd try to reset the computer first..... Can't hurt, then some new plug wires. Especially if they are still the stock ones.

Good Luck!

 

rkm,
A quick test for the wires; Spray the wires with a squirt bottle of water at night, if you see sparks the wires are scrap.
When you replace the plugs you have to pull on the plug wires to remove them in order to get to the plugs. They are prone to breakage when this is done. Pull them off and measure the resistance of each wire. Should be < 7000 ohms per foot.

If they are OK then check the plugs resistance. They should be between 2000 and 20000 ohms. You should also check the gap. The emissions sticker should have this speck. Are you sure the plugs are properly seated? Don't forget Never seize on the plugs and di-electric grease on the wire terminals.

Regards

Jean Marc Chartier

 

I guess you haven't learned your lesson. You're having problems with your aftermarket spark plug change and now you are considering aftermarket plug wires, heh.

 

Still to be determined if in fact is is aftermarket plugs causing the problem. I would think if it was a plug problem, it would have ran bad at the start, not 150 miles and two days later.

Tell me, where is the Motorcraft plug wire plant? I think someone of knowledge told me it was in a big building with a sign that reads, Beldin wire and cable.

At any rate, I am going to change the plug wires at least. I was only asking for input on a brand. I may change the plugs as well. I don't really want Motorcraft plugs, judging from the condition they were in when I removed them. These were put in by someone else at 34,000 miles. Thanks..

 

rkm,
All this uniformed b.s. about aftermarket parts being crap is exactly that-crap. I've sold aftermarket ignition parts for 15 years. The factory parts are not necessarily better, and are sometimes worse. Anybody care to put up a Delco or Motorcraft cap, rotor or wires against a Borg Warner Select set? Don't waste your time, I sell all three. The Borgs are much better. I've NEVER seen a set of Bosch platinums come back defective, but there's no such thing as a perfect line and I'm not saying that nobody has ever experienced a bad set.
I would recommend that in addition to replacing the wires (74K miles=overdue ) run a code check of your ECM. If a rich/lean condition shows, you may have an O2 sensor on it's way out, or it maybe something else altogether, but it never hurts to check your codes.
If the initial checks don't pan out, take it in and have a scope thrown at it. Don't do what too many Harry Homeowners do already: Replace part after part after part hoping to fix it.
Good luck,
Keith

 

I just want to throw my two cents in here. I have had nothing but bad luck with Borg Warner plug wires in my '97 4.6L. The first set was due to a misfire (new plugs & wires). I had over 50k miles & I new 4.6's were noted for eating plug wires. I was wrong, ended up being a corroded wire at the coil pack. Anyway, about 2 months later I had another misfire, code showed cylinder #2. I pulled the wire & plug to find the plug was rusted & had carbon tracking down the side. I replaced the plug. About a 3 weeks later I had the same problem with cylinder #5. I finally decided that the plug wires must no be sealing. I returned that for a new set or Borg Warners. These worked for a few months & then the same thing. Finally, 8 new plugs & a set of Motorcraft wires (much more expensive & I'm out the $$$ for the Borg Warner wire set) and I haven't had a problem for the last year or 20,000 miles.

Borg Warner - Great wires, but not in my 4.6

 

That is interesting considering I just bought the Borg Warner wires tonight. Not on yet though. Just wondering where you buy that Motorcraft is much more expensive. The Ford dealer where I bought mine, the Motorcrafts (out of stock) were $6.00 more than the Borg-Warners.

 

I bought the Borg Warner wire at a Parts Plus store. The Motorcraft wires from Ford were almost $40 more. This sucks when I'm used to paying less that $30 for wires on my old 351W.

 

Snappy has a good idea about the o2 sensors. Since you got 100k+ it might just be a good maintenace item to replace the two upstream ones.

When the time comes to replace my plugs and wires I'm considering the ford motor sport wires but I have yet to find a supplier and my closest dealer is not an svt dealer and does not stock them.