I recently replaced the plugs on my 2001 4.6 (bosch patinum plus 4's). I have used Bosch platinum plus 4's on my other Ford vehicles (contour w/v-6,
escort(many), 95 f 150 / 5.8 L and 98 mustang GT 4.6.)
Now that I'm done I've heard some negatives on them.
I'm just looking for any personnal experiences with them. I've always been pleased. Thanks, bullseye670.....................

 

You may get away with them however there will be lot of replies telling you they are no good. I would have used #6241s if you have to have BOSCH.
Good luck.

 

Never had good luck with them in any of my vehicles. The electrode is so small that it is easily fouled by deposits. There are less expensive plugs that work a lot better.

 

Never had any problem with Bosch platinum plugs in a 4.6L truck. I keep reading all the horror stories, but they deliver easier starts in sub-zero weather and better mileage on the highway for me... I've had zero problems with Bosch, can't say that about the OEM plugs.

 

Bosch plugs work better in Chevys then Fords.When I use to build them thats what I ran in them.I've seen more Ford trucks run like s*** using Bosch plugs then any other plug.

 

My 5.4 started and ran 10 seconds before in kind of popped twice then quit - I couldn't get it fired back after that. I wouldn't use them in any modular motor for reasons there not OEM . Most likely your performance is suffering in small enough ways your not realizing it. Your vehicle may run on them , but it won't run write which is probably why Fords didn't install any of these in there motors. There's more bad write ups about these plugs than good one's and with them not making an OEM grade - what's the point?

-Your motor deserves better.

 

So what should we run in the 4.6 liter motors? I bought a used 97 and replaced them with ?? right after I bought it. Might swap them out and check the checks since I have since learned about the spark plug blow out problems.

 

The original equipment (Motorcrafts) to be safe. Safe is debatable - What bugs me about Motorcrafts is that they do not incorperate a compression ring. The NGK is the only plug I believe out preforms the Motorcraft's and they also use the compression washer.

 

Oh yeah - that slipped my mind - sorry ..It would be safer with the compression ring for you then - People f up sometimes installing those tapered fit plugs "Motor-crafts" and then flame the manufacture - It's pathetic, but yeah - compression washers are a better way to tie them down I think and you go wrong with NGK..

Hope that helps

 

+1

 

Bosch Plat's and hot ignitions do not work well together, and COP is pretty hot.

My truck hit the 100k mark and I thought it was about time for some plugs. Working for the DoD at the time, had no where near enough time to mess with it so I dropped the truck off at Tune-Up Masters for plugs. They installed Bosch Plat's. In less than a month, the truck was running like absolute crap (hard cold starts, missing, popping, etc.) so I dropped it at the dealer to figure out what the deal was. They called me about an hour later and told me it was the Bosch plugs that were causing the problem. The center electrode was flat gone! There was a little tunnel up inside the ceramic where it used to be! They put the OEM Motorcrafts in there for me they've done great ever since! The service manager brought me out a bucket filled with Bosch pulls from other Fords, they all had the same problem. He said that the Ford COP spark is so hot that it just blasts the electrode out of the plug.

A buddy of mine was having the same problem a few months later, he said he had put in the Bosch plugs. I suggested he yank them out and take a look. Yep, same thing. So he replaced the with Motorcraft and that cured his issue too.

 

I have heard plenty of negative comments on Bosch spark plugs, which lead me to my installing of NGKs

 

Over 100,000 on my Bosch + 4's and not a single issue with them.... The "old school" mechanic in me tells me they should be done, but I keep pulling #1 to have a look and it looks fine...

Truck runs fine, I've never had to replace a COP. Well, except for #4 where the heater hose leaked on it.... Never a miss and I'm getting the same mpg as it got 100,000 miles ago??

If you are satisfied with a particular product that other's 'poo-poo' on, then you just have to decide if you want to go along with the masses on what they think, or go on what you can have seen first hand??

Good luck!

Mitch

 

If they work, run 'em.

If they don't work, don't be surprised.

 

Plugs are like the opinion about different oils.
Every plug make used will errode from the spark, not the combustion process.
All the makers have plat. plugs of one design or another and they all will errode for the same reasons.
To say such things as 'a bucket of BOSCH plugs' is nonsense. Where is the bucket of Motorcrafts, Autolites and all the others that are changed out?
When the electrodes wear, gap increases, the voltage at the top of the plug increases. If the boots are aged, hard and can no longer contain the higher voltage, leakage can occurr causing random missfire until a permant breakdown occurrs and flashover to the plug body or the head begins.
The plug center resistance has a large effect on this as well as power transfer efficiency to the spark gap, that starts combustion.
This is where the difference is between the old OEM and the new OEM designation plugs.
Next is the difference between the 97-99 "waisted spark" system that errodes plugs and a much faster rate than COP systems. This is one of the reasons the earlier system was abandoned.
It should be no surprise that installing hotter coils will make leakage worse if the parts are not changed more often because hotter spark is not the answer to marginal problems with boots and plug errosion that exist in the design.
.
Now for the rest of my little story on plugs. I chose the BOSCH #6241 for being a single plat type that has the same center resisrance as the original Motorcraft that came in the truck from the factory since the OEM are nonger available. It has proven to be part of the answer so far.
The coils 'all' measure a seconday resistance of 7000 ohms. I feel is a bit on the high side for stock coils but are not defective. Combined with the newer plug resistance makes the whole system marginal on plug life performance with the new Motorcraft designation. This reduces the power tranfer efficiency as mentioned above. This means less spark power in the ignition phase. It's not a case of voltage but of current in the gap to begin combustion process.
With higher series resistance, the voltage drops excessivly accross the plugs' center resistance causing poor or missfires that are random in nature and not setting codes. Then add to this the Ozone gas generated in a confined space that can't vent out very fast.
The reason this leakge becomes so important is the air in the plug well will breakdown at the higher voltages before the poor lean high pressure conditions in the combustion chamber will breakdown .
These actions can reflect right back to the PCM and upset processing such that any reaction could occurr from random transmission actions to fuel cutoffs, total ignition momentary cutoffs etc. that you can't pin down to any single known type of fault except to label it as feeling like a miss. Remember that the coils are directly driven by the PCM.
Would this suggest any specific codes be set? Very hard to assign a code if the PCM does not have a hard fault long enough to be a trigger.
The conditions under which this seems to most likely happen is when rolling into light throttle low load when the fuel is cut back and the EGR may be in operation. At this time the fuel is is very lean and very difficult to fire reliably.
Given an ignition problem of any type and you feel the results.
Lastly, i'm not pushing any specific make of plug but only chose one to fit the test in looking for the proof and a fix for the problem of short life and random missing. I know a dealer will never solve the problem. I may even go to another type in the final analysis along with some additions in the plug well to help the leakage problem. Something like useing different brands of gas and oil for percieved best results I guess.
Not everyone has the peticular problem.