Thread Number: 73455  /  Tag: Other Home Products or Autos
Bosch spark plugs...
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Post# 969973   11/25/2017 at 20:57 (360 days old) by cfz2882 (Belle Fourche,SD)        

About to give the 07 GMC Canyon new spark plugs-planning on using some Bosch iridium I had bought on closeout a while back.Discovered on some automotive forums that bosch plugs don't always have the best reputation...I have had good reliability and performance using "old skool"Bosch in my Porsche,SAABs,ETC And in some non-European machines too :) Can anyone here report any negative or unusually positive Bosch spark plug experience ?

Post# 970001 , Reply# 1   11/25/2017 at 23:28 (360 days old) by Supersuds (Knoxville, Tenn.)        

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I used Bosch platinum plugs in my old (1989) Peugeot 405. The mechanic at the dealership was horrified and always changed them back to the factory brand (which I think were called Eyquem) and it was easy to tell because the idle was rougher. The only difference I could honestly tell the Bosch made was the smoother idle, but there were certainly no problems.

The Peugeot had an aluminum head and I liked the smoothness of the threads on the Bosch plugs. They weren't as sharp as the threads on American brands like Champion or Autolite. Seemed to be a lesser chance of cross-threading.

Post# 970039 , Reply# 2   11/26/2017 at 07:13 (360 days old) by askolover (South of Nash Vegas, TN)        

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Lately I just use what came in from the factory...AC Delco, Motorcraft.  I tried Bosch once and wasn't impressed.  Out they came.

Post# 970073 , Reply# 3   11/26/2017 at 10:45 (359 days old) by vacerator (Macomb, Michigan)        
I haven't

changed a set of plugs in 2 decades. Theyr'e good from the factory for at least 100,000 miles now. Even longer on a direct injection engine.
Of course, there is always the exception. Too much city driving, long term high speed burning of the electrodes, etc.
If it fires up quickly, idles and runs smoothly, and fuel economy is good, imho, a waste of money.
Not to mention so many are difficult to service theses days.

Post# 970078 , Reply# 4   11/26/2017 at 11:12 (359 days old) by cfz2882 (Belle Fourche,SD)        
plug life

The GMC Canyon is "coil on plug"design,have to take off some stuff from the top of engine,pull up the coils to get at the plugs deeply recessed in the head :)Truck about to turn 130,000.I ran a set of "old skool"AC plugs 80,000 my '82 z28 350 once and though HEI was still firing them fine,they were well worn:gap openened way up,center electrode very rounded :) "big cap"(~'74-86)GM H.E.I.was a very good ignition,unit on the '82 z28 original to the car and ~268,000 far,only parts I have changed is the rotor and center contact.Later "small cap"HEI(1987+) still good,but tends to build up ozone and moisture under the cap.

Post# 970254 , Reply# 5   11/27/2017 at 12:43 (358 days old) by robbinsandmyers (Hamden CT)        

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I only use NGK in everything. Much better plug.

Post# 970262 , Reply# 6   11/27/2017 at 13:17 (358 days old) by Yogitunes (New Jersey)        

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I use the Bosch in my Jeep...but then again, those are factory installed as well....

mine take 16 plugs......

Yttrium on the intake
Irridium for the exhaust

they are specific of which one goes where.......

I too have to the coil on top of the spark plug.....and had those rubber sleeves break off down inside, as they stuck onto the plug.....

had to use a screwdriver and slide it down the hole, and snap off the top of the plug, then you can remove the rest of the plug....

they hold up and work very well......

Post# 970405 , Reply# 7   11/28/2017 at 15:08 (357 days old) by firedome (Binghamton NY & Lake Champlain VT)        
also use only NGK

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in mowers, boat, old and new cars... they are the only plug that seems to hold up well in 2 strokes which fire twice as often. We used NGK exclusively at the boat dealer when working as an outboard mechanic in the summer, in 2 and 4 stroke outboards and in automotive-block I/Os and inboards, never had a failure. Can't say that about other brands.

Post# 970429 , Reply# 8   11/28/2017 at 17:19 (357 days old) by washman (Butler, PA)        
I used to use Autolite exclusively

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But since they offshored to China and Mexico, I switched to NGK. At least they are made in Sissonville WV. 


Use the NGK Iridiun (sp) in the Toyota-san. No issues there.  I will put NGK in the Huksy non union rider when the time comes to replace the Mexican sourced Champions. The Echo trimmer came with NGK and I will stick with that.

Post# 970988 , Reply# 9   12/1/2017 at 15:29 (354 days old) by kb0nes (Burnsville, MN)        

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I generally make a point of using whatever they used as the OEM plug. Years ago when the Bosch Platinum's came out I was changing them in everything. At times I felt they made a difference, although not always for the good. One car didn't seem to pull as well under load with the Platinum plugs as with the OEM standard ones.

From a machining standpoint, I always thought the Bosch plugs had the nicest threads. They were rolled well and nicely deburred. No matter what be sure the threads are properly greased before installing.

Second guessing the engineers really isn't always to our best advantage

Post# 971026 , Reply# 10   12/1/2017 at 20:53 (354 days old) by Yogitunes (New Jersey)        

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Phil is right though.....when the Platinum's came out.....I installed them in my Chrysler 2.2 Turbo would start, but no power to move the vehicle....finally had to switch back to Champion's, then it ran as normal....

Champions seemed to burn out fast in Chryslers 2.2/2.5...Turbo and Non-Turbo versions...about every 30,000 mi.

Chrysler had a good set-up with those transverse engines in the 80's, everything up front, even the intake was easy to remove and lift off from the back part of the engine...

todays cars, even a 4 banger is packed in there tight....

Post# 971027 , Reply# 11   12/1/2017 at 21:05 (354 days old) by GusHerb (Chicago/NWI)        

I had my mom order the OEM plugs for her Sonata with the turbo after doing research and finding they don't do so well with other after market spark plugs. That car also calls for a spark plug change at 45,000 miles. Direct Injection is apparently harder on spark plugs, which that car has.

Post# 971039 , Reply# 12   12/1/2017 at 22:31 (354 days old) by cfz2882 (Belle Fourche,SD)        
Hyundai OEM plugs

I bought a few boxes of Hyundai OEM plugs(they were $1/box of 4,so couldn't resist :)some of the plugs were NGK,others Champion made in Korea.

Post# 971040 , Reply# 13   12/1/2017 at 22:36 (354 days old) by kb0nes (Burnsville, MN)        

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With modern spark plugs and electronic ignitions the service interval is soooooo long. I just passed 71K miles on my 7 year old car, maybe in 3 more years I will need to replace the original plugs!

Things are sure different then years past, modern cars require so little maintenance

Post# 971048 , Reply# 14   12/1/2017 at 23:37 (354 days old) by GusHerb (Chicago/NWI)        

My Nissan doesn't call for a spark plug change til 110 or 120k miles. I'll likely never have to change them!

Post# 971133 , Reply# 15   12/2/2017 at 11:39 (353 days old) by washman (Butler, PA)        

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Same thing here Yogitunes, my K based mopars digested champions like corn flakes.  The 2.2/2.5 never idled smoothly anyway but with Champions in there, yeeeesh.  I switched to Autolite and problems went away. In fact, I was so taken with Autolite I put them in mowers, chain saws, pretty much any internal combustion engine.


Then over the years, production was offshored to China or downshored to Mexico. After that, I sought NGK plugs as they are made in WV and I have had good performance from them. 



Post# 972870 , Reply# 16   12/10/2017 at 17:52 (345 days old) by GusHerb (Chicago/NWI)        

Replaced the plugs for my moms car today at 53k. Replaced NGK with NGK. Old ones had blow by around the ceramic, didn't look too bad but were definitely ready for replacement. Didn't notice any apparent changes in the way it ran but I took it for a quick spin and it seemed unusually powerful compared to normal.

Post# 972901 , Reply# 17   12/10/2017 at 21:34 (345 days old) by Stricklybojack (San Diego, CA)        

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ND (Nippon Denso) spark plugs are often over looked.
I think they are now marketed simply as Denso spark plugs.

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