Bosch WG175T30 contained in trunk/boot toolkit

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lloyd

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I noticed a post from another board mentioning this plug, but no one there seems to know anything about it. What makes the plug different is the shroud/cover/apron surrounding or protecting the ceramic nose/tip of the plug.

As most of you know, three of these were standard issue as part of the toolkits. I think I still have mine, albeit somewhat corroded over the years. Bosch does not seem to list them, or at least not with the "G" and a Google of WG175T30 proved futile. The only time I may have encountered them, other than in connection with an E3 or E9 toolkit was "possibly" with an early 70's 280SL. These plugs were obviously not very popular, but I wonder, if anyone on this board might shed some light on the topic.


Did the E3's and E9's actually come equipped originally with these plugs?

Since BMW went to the trouble of furnishing these plugs with the toolkits, do the manual's actually specify this "G" style plug?

Any other cars use the same plug?

Was the same style plug available in different heat ranges?

Was there a specific function or advantage to using these "shrouded" plugs?

Thanks in advance.
 
Dear Tilla:

Your reply is appreciated, but I am afraid it does not fully address my question.

I am familiar with that chart and other charts and cross reference tables. Unfortunately, none of them seem to cover the subject plug: WG175T30. It's both the "G" and its placement within that series of letters and numbers. I posted the markings exactly as embossed on the plug: "WG175T30".

I am aware that the heat range and reach are identical to the W7DC (although I suspect Bosch has even changed that label too by now.) But if you examine the business end of that plug you will see the difference right away. Its the metal welded to the plug base which surrounds - but does not touch - the ceramic insulating nose. I would expect there to be some reason for that particular design, even if it was a not-too-good one.

Again, one would think someone has posted something about this forgotten plug on the net, but I have yet to see it. Unfortunately, my digital is elsewhere, otherwise I'd post a picture.

Thank you again for your indulgence.
 
Interesting, I looked at the same chart but must have overlooked the "G" "surface gap spark plug with ground electrode" description.

But how can it be a standard "ground electrode" and "surface gap" at the same time? The subject plug looks like a standard plug ordinare with the exception of the "shroud". Yet, its obvious that the spark jumps between the center electrode and "L" bendable "hook" or side electrode. I am familiar with typical surface gap plugs. Hey, wait a minute, maybe this is why the plug was not the most popular seller.

Thanks again for you effort, but I am afraid this plug and its story shall remain shrouded in mystery, or is it misery? :)
 
Just happened to look at this, it specifies the plug under "special equipment"

at_a_glance.jpg
 
WG175T30 - Special Equipment!

Thanks Tilla for your latest effort. Now I am again compelled to ask what did this Special Equipment sparkplug offer except perhaps some sort of bragging rights. I also wonder if any of the E3 and/or E9 cylinder head's were actually equipped with these "exotics" from the factory and why?

Like finding the illusive build sheet, this information may not be significant, but perhaps someone out there can shed a little more illumination on the subject.

Thanks again.
 
Generally speaking, surface gap plugs are more reliable because of multiple spark paths vs. just one on a normal electrode plug. They also handle higher compression better. F1 cars use a form of surface gap plugs; Alfa Romeo specified Lodge surface gap plugs for it's 4 cyl cars for years.
 
Surface Gap more reliable?

Thanks for the followup Tony.

I noted your conditional language re "generally." Any idea if these plugs were special standard equipment? Can one assume the standard issue non surface gaps were as good as these special hybrid-surface gap plugs. Thus, they would be the exception to the "general" rule.

What gets me though, is I dont see how they are surface gap at all. As noted earlier, it is nothing but the standard electrode plug with a "covering" for all but the very tip of the ceramic nose. It does not seem that any spark jumps to this "covering." You mentioned multiple or alternative spark paths. But on this "special" plug, there really is only one path. This is unlike multi-electrode plugs (which are commonly used in piston driven aircraft and to a lesser extent autos (Mazda Rotary) and true racing surface gap plugs where the spark jumps from the center electrode to any point on the shell surface.

Thanks to all for your collective indulgence.
 
Lloyd, honestly I've never see the plugs you describe. If you could post a picture it might help. The only original equipment plugs I've ever found in the trunk of a BMW were Beru, and they were normal single electrode.

Cheers,
 
OK, those are just plain weird. They look like a hybrid standard/surface gap plug. I suppose you could argue that if the gap to the regular electrode becomes too large to bridge a spark, the side electrodes might pick up the slack.

The other possibility I can imagine is the metal prongs on the sides are somehow supposed to shroud the ceramic insulator and keep it cooler? I dunno, that's a stretch.

Considering that's the first time in my life I've seen a plug like that, I'd venture to guess the idea did not prove to be a huge success for Bosch...
 
Would guess the Beru "special air surface gap plugs" look just like the Bosch version. I have seen some Beru's similar to these, but without the "J" electrode. :)
 
While this may not be of foremost significance, I wonder if anyone can remember if these "special" plugs were ever actually installed in the E-9 and E-3 engines - rather than left in the boot/trunk toolkits for show. :?:
 
Unusual Sparkplugs in the toolbox--long discussion-------

Some history and overview/reminder for E-9 owners under the age of 65:

When these cars were built from 1968-1975--the German engineers knew they would be going to places and driven in locales far removed from a handy neighborhood BMW Dealership or factory trained MM--both were few and far between 32-39 years ago--BMW was a very small mfg'r in that time with very limited service facilities and/or trained technicians outside of Western European Metro areas--so in order to meet expected needs to service or pemit owners to handle many basic repairs--the toolboxes in the E-3 & E-9 were then well equipped and the owners handbook's were a fair guide to your non-BMW mechanic for basic needs.

Here in the Colonies--specifically here in Orange County California--today likely the present home of more BMW's per capita than most places here or abroad--there was one well known Independent BMW service facility in the early 1970's--Schneider Motors--known to all of us early Bimmer Heads and a favorite gathering spot on Saturdays to chat with other early BMW folks like Leif Anderberg--our well known local Swede who was a key organizer of the Los Angeles chapter of BMW ACA and knowledgable contributor to early Bimmer lore--Crevier BMW--now the largest in the USA--was then a little "hole in the wall" on W. 1st Street in Santa Ana, CA


Keep in mind--most original E-9 owners were very affluent people who could afford to buy a Coupe--but were very unlikely to personally address its service or repair needs--the toolbox was often opened for other than maintaining the cars and many tools disappeared--especially red handled screwdrivers.

in answer to the questions as to use of the "special" sparkplugs--yes--they were there for that purpose as were all the complete and correct Heyco chrome vanadium tools that populated the boxes special indents molded for each.

So---after all the long drawn out unique plug discussion--my question is now--how many E-9's out there still have all their "correct sets" of the original issue Heyco chrome vanadium tools--and whatever plug that works now??

BLUMAX has all of them--and a couple of the "special plugs too!!
 
Tools

Got the plugs and all of the tools, except the small screwdriver....still looking
 
Mundane answer for mundane question

In answer to my own question, I found a water-stained Haynes manual for the 2002. One of the few legible pages lists spark plug applications. Among other things "Bosch WG200T30, W175T30, and Beru G/200/14/3 are some of the indicated spark plugs for the Tii. Thus, it appears there were other variations of these "special" spark plugs. Parenthetically, the similarity in Bosch and Beru numbers makes one wonder if they were not made by the same company and merely repackaged, recolored, or rebranded.

In answer to Blumax(George Peppard?)'s question, I started out with complete toolkits, but most of the tools have been liberated by unknown individuals over the course of many yearsl. Blumax did not ask this, but in my uneducated opinion, the toolkit placement was convenient, but short sighted, given the effects of gravity and occasionally less-than-perfect road conditions.

While on the subject, I wonder how many owners actually used the supplied Heyco implements- unless absolutely necessary. Again, in my opinion, the wrenches and screwdriver is fine. But, being blunt, the fit and finish of the floating jaw/waterpump pliers is a poor excuse for any serious use other than prying and hammering. The lineman's plier is also not my first choice in that the few examples I have owned exhibited peeling chrome plating and took two hands to operate. Maybe its just my limited experience, but it is what it is. The spark plug removal tool looks too similar to my Model T and A and tractor tools to invite routine use on this sophisticated machine from the 70's!

Lastly, Jamboree Road and nearby OC environs are hardly the coupe capital of the continent. Bluemax needs to dust off the ol' Tri Fokker, don his flying leathers and recon neighboring LA and S.D. Counties. Reliable intelligence indicates he will likely find many coupes in various states of battle readiness equal to his home base of operations. Reliable sources indicate Blumax may be seriously underestimating the coupe rear guard numbers in the Bay area too! :lol: :lol:
 
Storytime--BLUMAX and Jamboree Rd.--"The Hub"

both have deep roots in and around this area where the Boy Scouts gathered at the buffalo ranch once upon a time--voila--a good name--Jamboree--for that key surface roadway from Irvine Park in the foothills to Balboa Island at Newport Harbor--or the reverse--

long ago and hereabouts it was even possible to race my neighbor for several miles along MacArthur from Corona del Mar--without interference of traffic signals or the gestapo to the then 2 lane 55 freeway--and on to our respective offices in Santa Ana and Orange--John Wayne Airport was a virtually unknown place except to general aviation buffs

Have been here in the OC since "BC"--Before Coupes with the "big six"--BLUMAX was assembled in early Fall over a year after I arrived here from the East Coast--then just a rare few 2000CS's around--am long familiar with MANY owners around the basin and was among the original attendees at Laguna Secas at now forgotten CoupeFests at turn 5 in the 1980's when 60-80 would attend even with the whole place deep in dust--not like the oasis atmosphere of today presented by the Golden Gate Chapter, etc-- previously in 1974 BLUMAX made his first trip to attend the Concours d'Elegance at Pebble Beach when it was a very posh, not too crowded affair and tickets were $20--HHhmm big change since

Also--was for several years a judge at both the SD & LA Chapters annual CCC--clean car contest--made a few friends and possibly a few enemies in that capacity--

so I repeat--that with finger firmly in the air--testing wind, not jesturing-- and on the local BMW pulse--my statement stands until corrected--OC is the most likely hub of concentrated Coupe ownership per capita in California--grant you--it might be interesting to conduct a census of the Bay area and the Lost Angeles areas you have noted--to find the "real" Coupe hub--maybe slip those "special performance plugs wherever most comfortable"--and--are you volunteering--eehhh Lloyd?? (;>)
 
Blumax, I have visited your area of the country and concede you are in a better position to opine on hub data. My eyes, having viewed many areas, e.g., BH, Pasadena, S. Marino and Santa Clara County, to name but a few, make it easy to draw a slightly different conclusion. I suspect there is a lot of inventory that neither you, nor the "hub inspectors," nor aerial reconnaissance, have yet detected. (This may be hopeful thinking on my part - but consider the Schlumpf museum as but one of many very very private collections. Besides, if your garage or barn is big and cluttered enough, and you are like me, its easy to forget what you parked or where you parked it!)

What ever the latitude, I am glad there are a good number of folks that hang on to the E9's and E3's.

On another note, your omnipotence is more than a little bit daunting. From what I have read, all of Southern California is suffering from a significant drought. Some of us find it amazing how far you will go to implement your waterless car washing edict!

From some former locals and long time friends, a lot of merit badges were awarded in 1953? to 50,000 + scouts on what is now Fashion Island. ':lol:')
For the uninitiated: http://www.tcninteractive.com/nb100/story_boyscouts.htm

Respecting the placement of special equipment, I’ll pass - despite your suggestion of comfort. :wink:
 
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