Bosch Spark Plugs

SkyPup · Jan 31, 2006

I've been running BOSCH Platinums for the last ten years in my GM 350 V-8 and have never changed the plugs yet....

I'm running the Nippon-Denso Iridiums in all my high performacne racing motorcycles and kart engines, they are the absolute best.

None of our numerous half dozen diesel engines care for any of the various brands of plugs though.... /forums/images/graemlins/grin.gif

HGM · Jan 31, 2006

Again guys, in my experience Fords dont like them. Because of my experience, I wont use the generics... Cant speak about the AC's or even GM liking the Bosch... I'm sure they run good in something.... NGK's I have used in bikes with good results too..

For the 4.2L 5spd.. It's a good setup and does what its intended to do, though it doesnt have allot of power or towing ability. If it suits your needs, it should last you a very long time..

The only issues that come to mind with the engine are EGR ports clogging over time. This will cause a missfire because EGR is excessivly flowing into one or more cyl, instead of equaly. The only way I know to fix it is to remove the intake and clean it... No definitive way to prevent it either, though it sounds like you have good maintenance habits and may not have this issue.. The trans, I would check the fluid every so often(30-50k mi) and make sure its full(ATF, not gear lube), there are some shift rail plugs(rubber) on the top rear of the trans that tend to leak over time(no puddles because it follows the driveshaft and rear end housing, doesnt drip).. This will allow the trans to run dry and overheat.. When you notice(w/o checking the fluid) its too late, the trans "melts" internally destroying 80% of the parts.. Its cheaper to buy a new one than repair it at that point and its not cheap..

deerefan · Jan 31, 2006

I don't tow much w/ it, kinda figured it did not have much towing power. Not too hot on acceleration either! I do need to service my trans, though. Never have. I do like the simplicity of it though. Easy to work on. I can track down some motorcraft plugs...would rather use what it calls for anyhow. Thanks again for the input.

donaldprice · Jan 31, 2006

I've been running bosch platinums for a long time in a GM 4.8 2001 /forums/images/graemlins/blush.gif

slowrev · Jan 31, 2006

On modern engines it really should not matter much which plugs you run. I run standard Autolite plugs with very good results. Had one early Bosh platinum plug lose its ceramic stuff around the electrode once in my soobie, not a good thing to have rattling around in your engine.
Ben

JerryG · Jan 31, 2006

I wish I could give you some electronic reason why this is, but unfortunatly I cant. Comon sense would tell you that the electrons dont wouldnt care, but in this case I'm a firm believer they do.
That is the exact same thing that I have said for several years now. I have tried just about every brand of plug at one time or another and the only thing that I can get to last very long and do a good job in the Fords that I have owned are Motorcraft plugs. I have no idea what causes it but that seems to be the way it is.

robison · Jan 31, 2006

Greg, with respect to your comment about how many "off brand" plugs you have changed in Fords over the years . .

I have spoken with our Bosch service trainers about this and indeed I've said the same thing in other contexts. Older Land Rovers, for example, use Champion rn11yc plugs and I've changed numerous Bosch, NGK, etc for the same reason.

But is it valid???

Let's assume for the sake of argument that you are a Ford tech in a dealer. Have you ever taken 100 identical trucks and fitted 50 with Bosch plugs, 50 with Motorcraft and seen what happened over time with similar use? Of course not. Dealer personnel are not in a position to engage in such experiments.

As a specialist in one make we see the off-brand plug and we associate it with "inept service" or "cheap aftermarket parts"

It may be the wrong part number (we don't know, we only know Motorcraft numbers) It may have been dropped before installation. It may have been gapped wrong. There may be a wire problem. There may not be anything wrong at all.

We change the plugs for oem, we do other "tune up" work, and the vehicle is good to go.

The point is, there are many reasons for replacement of plugs other than "oem works better"

For most Ford engines Bosch has 5-6 possible plugs, only one of which is going to provide oem performance. Others may provide "better" performance while the remainder will provide lesser performance. By lesser I mean they can be used in a pinch and changed early.

Bosch supplies spark plugs to Ford and GM under their brands. Ford and GM drive on Bosch engine management parts, and many other systems.

If we install the correct oem match Bosch plugs in a Ford vehicle Bosch warranties them - parts and labor - for the manufacturer service interval at an authorized Bosch automotive service center. Most people don't know that but they do stand behind their product. If I installed Bosch plugs in your Ford and they did not go the 100,000 mile manufacturer service interval Bosch would pay me to change them for you for free.

I agree with you that we get a level of comfort seeing oem service parts on a car. And we tend to associate oem parts with a higher quality of service. But it's not always true.

To put Bosch's operations in perspective . . .

Ford's worldwide sales last year were about 150 billion dollars. Bosch's sales were just over half that. Bosch is consistently profitable, and Bosch has a considerably higher net worth than Ford at this time.

Bosch is the largest filer of automotive related patents in the US and Europe most years.

HGM · Jan 31, 2006

( Ford's worldwide sales last year were about 150 billion dollars. Bosch's sales were just over half that. Bosch is consistently profitable, and Bosch has a considerably higher net worth than Ford at this time.)

Man, that was a low blow /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif...

Seriously, I do agree that Bosch makes good products.. No argument there.. Could it be that the marketing of Bosch plugs in PepBoys,AutoZone,Advance,etc.... could lend to the problems I have seen? You, largely, have inexperienced enty level parts people selling a particular plug for a particular engine(you mentioned 5 different options), could they be giving the wrong ones??

Sorry, I still maintain that a Ford (typicly) responds better to the ignition components that it was designed with... Is it possible for one to install Brand X plugs in their Ford and have it run as good as new, absoloutly...I personally would rather spend similar money, once, and install the right stuff...BTW, as to your coment that maybe another component fixed it and the plugs were fine, under most circumstances, when I see an aftermarket plug it goes first. Wires should be fine past 100k without a problem, we rarely use them anyhow....

TractorLegend · Jan 31, 2006

I am not a dealer tech but service several different makes (see profile). I agree with HGM on the need to install Motorcraft double platinum plugs in the late model Fords with waste spark systems and/or coil-on-plug ignitions. We have also seen many other brands cause misfire codes and a check engine light to illuminate. I could save a few bucks on my parts bill by going with other makes but experience shows customer satisfaction to be low when you have a problem soon after a tune up. Ford could have saved themselves an almighty nickel if another cheaper plug worked as well.
I would not go 100K on a plug---two reasons. The V-10's spark plugs tend to loosen and there has been issues of threads and plug blowing out. And even if it doesn't loosen, you risk them growing in place. Some new spark plugs earlier with some anti seize compound on the threads can save you expensive headaches. Change plug wires too (if you have them) anytime over 60K. I like Motorcraft for fit there too on Fords. This is my observations based on non scientific data- take it or leave it.

HGM · Jan 31, 2006

Just a tip, if you arent aware of it yet. The main reason found for the plugs blowing out on the modulars is that they were loose to begin with.Very rarely will a factory(original) plug blow out.. It's usually after a tune up has been performed and the tech didnt torque the plug tight enough...People get scared of the aluminum head, just tighten it, it will be fine /forums/images/graemlins/grin.gif..

I tend to let the wires go longer, but appreciate you chiming in so it doesnt sound like I'm crazy /forums/images/graemlins/grin.gif..