engine and drivetrain Bosch Platinum

[gaius]

i came across two sets of Bosch WR7DP Platinum plugs in my stash, are these good plugs for a stock M10 engine. and yes they are un open, but maybe 15 or more years old.

[KFunk]

nah, don't do it.  I can't remember the reasoning exactly, but they don't work well with the M10.  

[PaulTWinterton]

I have a 15 year old set as well. Can't seem to through them away.

 

AFAIK nothing beats the BP6ES plugs.

[bento]

My car came with a set installed. It seems to run fine but idle isn't as smooth as I'd like. I ordered some Bosch Supers to try out and can report back when I make the switch.

The only concrete reason I could find when searching on the topic was that they foul more easily than standard plugs.

I'm curious to hear from the experts if there's more to it than that.

Since you have them, what's the harm in running them for a while? If it runs worse, throw them away. Not like they're worth the trouble of selling.

Edited October 24, 2014 by bento

[KFunk]

It'll run OK with them.  I've used them in a bind when thats all the parts store had.  They just don't last as long as normal plugs will, which kind of defeats the purpose of spending extra on platinums.  

[ray_]

They suck.

[Mike Self]

Funny thing...for some years I heard that the Bosch Platinum plugs wouldn't work well in an '02...then I installed a set pretty much out of desperation as I needed new plugs RIGHT NOW and that was all I had on the shelf.  They've been working just fine for some few years, so I'm not sure what to think any more.  I still have a conventional ignition system (points and standard coil)...perhaps the platinum plugs don't like HE ignition systems...

 

mike

[gaius]

perhaps the platinum plugs don't like HE ignition systems...

 

thats an interesting thought, i run stock ignition as well, might give them a try. i have always run NGK's in all my motorcycles,and aluminum head cars. but i have two boxes...

[ray_]

Hmm, well. My tii with conventional ignition, Bosch red coil didn't like them many moons ago.

 

The 1600 I acquired recently had them installed (blue coil conventional) and the idle was awful. Copper plugs cured that.

 

YMMV, apparently.

 

Cheers,

[jrhone]

I thought it was because they could foul more easily.  This would mean if your car burns a bit of oil, they may not last long.  If your car has a more recent rebuild or burns clean, maybe not such a difference?

[71bmr02]

I ran platinum plugs with a  large plug gap (maybe 45 50thou) when I had msd6al and msd coil and the combo worked well.  when the msd gave it up, I went back to std ignition, points, condenser etc and the set-up didn't play well with the platinum plugs.  went back to bp6es and all is well.  My experience indicates they seem to work ok with upgraded ignition but not so well with stock ignition.

 

Gale H

[Roland]

Funny thing...for some years I heard that the Bosch Platinum plugs wouldn't work well in an '02...then I installed a set pretty much out of desperation as I needed new plugs RIGHT NOW and that was all I had on the shelf.  They've been working just fine for some few years, so I'm not sure what to think any more.  I still have a conventional ignition system (points and standard coil)...perhaps the platinum plugs don't like HE ignition systems...

 

mike

 

 

 

I  thought you ran a capacitive discharge ignition add-on like the Delta Mark10?

 

In my experience, from their inception, the platinum plugs were prone to problems when used with the standard kettering ignition and leaded fuel.  I was under the impression that they were designed for the "newer" lean burn electronic ignition equipped engines, most of which, made use of larger plug gaps jumped by shorter duration but higher voltage electrical arcs.  Despite emissions reduction progress, most stock 02 engines tended to run the fuel mixture spectrum, rather than a tightly controlled lean-burn, managed mostly by smart fuel injection and exhaust catalysts.  Yes, there were precious metal fine-wire plugs available when the 02 was first sold, but those were primarily for racing and they were not designed for long life or reduced maintenance.  Also, through much of its production life, the 02 engines required more frequent maintenance due to leaded fuels.  I am not aware of any authority that recommended the first platinum plugs for use with leaded fuels although parenthetically, it is hard to image any plugs that were specifically recommended in the case of fuels that were prone to leave deposits.  Early platinum plug reputations were not enhanced since, as noted, platinum plugs that might test the weakness of the '02 standard ignition system, could be further compromised by increased tetraethyl deposits.  (Add this to the '02s reputation for sucking oil past valve guides and seals and it is hardly any wonder why the more expensive plugs were disfavored.)    I experienced quite a few Bosch platinum plugs that mysteriously lost their tiny platinum electrodes shortly after installation.  That even included the once-available nonresistor versions.

 

Even if the above "bugs" had been eliminated, the newer air gapped multi-electrode platinum plugs present the same problems for the stock points fired ignition system.  Those plugs may test the limits or expose the weakness of the stock ignition system resulting in an occasional misfire.  Incidentally, most of the FAQ'ers are aware that plug makers other than Bosch have their own versions of so-called "platinum plugs," e.g., Autolite and Champion.  Although the designs are slightly different and some have double the platinum, even if you could obtain plugs with the appropriate heat range, in my limited experience, these plugs in a standard ignition-driven '70s or earlier engine, provide little if any benefits over the stock copper-core or silver-core plugs.  That being said, new plugs of virtually any sort are likely to be an improvement over severly worn and fouled stock plugs.  But the improvement will usually be short lived.        

 

Meteor-supplied Iridium plugs in the stock M10 or M30 engines may present a different situation than that created by use of the standard Bosch platinum plugs.  Toby?

 

 

 

 

Gratuitous pictures?  Without Johnny.

 

[gaius]

i guess i will stick with NGK

[rstclark]

My stock 2002 with conventional ignition and coil has platinum plugs and it idles rough  Plugs are gapped at .35  I have a new set of NGK BP6es to install, but what is the best gap for this stock setup?.  A reference book says to gap them at .24  but I just can't believe that is correct .Plugs are now a little sootie but not oily

[peterschop]

A couple of years ago my POS Dodge van had a catastrophic melt down of it's catalytic converter. The shop that put on the new converter on pulled the plugs and found that one of the Bosch Platinum plugs had lost the center electrode and let raw fuel pass through and destroy the CC. The electrode must have passed through the engine too. Needless to say, I no longer buy any Bosch plugs.