I have not used a Bosch spark plug since the 1970s, when they were OEM on my boxer twin BMW motorcycle.
I would only trust NGK or Denso plugs.
I would only trust NGK or Denso plugs.
More problems with Bosch spark plugs
- Thread starter Chris142
- Start date
Not just Bosch, had my work truck in for a tuneup and specified GM oem plugs- it really is worth the time to check gaps before installing as I had to return for a misfire wasting everybodies time.
Yeah I know you're not supposed to check modern Iridiums but sometimes you have to regap because one plug is listed for several makes. I feel like I went through this on a Kia recently.
I use my gap gauge gingerly and pry open with the Lang tool or push closed with the red aluminum threaded "press"
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Regarding brands I've run Autolite Iridiums in stock GM LS (5.3) applications with zero problems. Kinda funny because Autolite is "supposed" to be Ford but it worked fine for our old GMT800.
???
Please explain what I'm missing here. How can the spark plug gap not face the cylinder wall (unless it is a Wankel rotary engine)? The cylinder wall is 360 degrees around the plug.
I got away from BOSCH plugs many years ago unless its OE spec, and that is probably never going to be the case for me.
However, the take away is that many people (and for good reason) recommend using ONLY the OE plug of which I do subscribe to the same mindset.
I myself learned this the hard way years ago in one of my JEEPs! I thought I was doing the ignition system good by going to a platinum plug instead of OE copper, I was very wrong and have never second guessed it since... I just stay with the same exact PN.
Here's one for ya... My MAZDA 3 with the 2.5MZR calls for Champion as the OE plug, not DENSO or NGK. Yet our CX-5 I think does spec an NGK.
However, the take away is that many people (and for good reason) recommend using ONLY the OE plug of which I do subscribe to the same mindset.
I myself learned this the hard way years ago in one of my JEEPs! I thought I was doing the ignition system good by going to a platinum plug instead of OE copper, I was very wrong and have never second guessed it since... I just stay with the same exact PN.
Here's one for ya... My MAZDA 3 with the 2.5MZR calls for Champion as the OE plug, not DENSO or NGK. Yet our CX-5 I think does spec an NGK.
In laymen terms;
Indexing your plugs just mean aiming the electrode in the most effective direction and you do it through indexing spacers (essentially aluminum washers that you torque down on). This is a thing in really high compression engines or race applications usually to try and gain the maximum effectiveness of your ignition timing by uniformly pointing the plug electrode gap toward the intake valves. This would not be relevant on the average modern consumer grade vehicle...
Oh, I fully understand what indexing plug electrodes means...it is routinely done by NASCAR and Formula One teams on race engines. I am asking how do you index plug where the gap doesn't face any part of the cylinder wall as stated by loneryder in Post #16. He did not say align the gap with the intake valves.
The top surface is not necessarily flat - it can be pented or domed. If the plug isn’t centered, the “open” end might be facing back into the head.
AZjeff
$50 Site Donor 2023
Could also be saying the gap is facing the closest wall of the cylinder if the plug is offset.
Never mix german and japanese plugs and cars.Use NGK or Denso
japanese plugs go to japanese cars, german plugs to german cars.
SammyChevelleTypeS3
$50 site donor 2023
Yes, it is a shame lots of things are not the same.
A lot of issues today that were not issues in that past make me suspect this "new world order" manufacturing and sales thing the entire world is addicted to could be part of the problem. Too many manufacturers are stuck buying parts from all over the place. Quality became a hit or miss over the past 25 years. Why is that?
There are no longer many or any 100+ year old , well established , extremely good and top shelf quality companies like in days past. Seems like there are no more companies that live / survive based on their quality/reputations and standing by their products. Plus today companies are likely having everything assembled in the cheapest places they can find. Possibly even forced to jump back and forth from place to place for parts and maybe even assemblies? Who knows these days.
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If it's a publicly traded company, you can bet your bottom dollar this is their approach to parts manufacturing.
I ran into issues with Bosch plugs back in late '90s and early '00s and just steer clear from them since. Using mostly NGK and occasionally Denso.
With some plugs the number of threads can cause it not to be indexed correctly. My indy MB shop uses only MB plugs by Bosch and said sometimes they have trouble getting them indexed properly.
Had a mustang back in the day, I too was swayed by the "oh it's platinum, must be good" marketing back then. Engine ran terrible, and here being a beginner thought the ignition system needed to be replaced. Still engine ran like junk.. couldn't be the "best thing ever" plugs.. but it was. Switched back to Motorcraft plugs (probably autolite made them) and instant success! Engine ran perfectly.
Now the Bosch brake rotors, quietcast has been awesome, perfect low run out, etc.. But we're talking ignition system stuff here, Bosch.. never again.
Now the Bosch brake rotors, quietcast has been awesome, perfect low run out, etc.. But we're talking ignition system stuff here, Bosch.. never again.
Understand that ...but what's the difference between them to cause problems mixing? Been wondering this for a long time.
Could have been handled poorly while still in the packaging. I'm running Bosch double platinum which are OE for my BMW and they've been fine.
Bosch appear to be OE.
The boxes were not damaged and they all had the cardboard protective sleeve on them. If they got damaged it happened at the factory?
With my experience with cars I advise you the following when it comes to spark plugs. Always always always use the spark plugs that are OEM for the vehicles engine. Examples: motor craft for Ford's, ac Delco for gm, denso for Hyundai/Kia etc. The OEM plugs were spec for the engine. Also do not gap iridium plugs. Also install spark plugs dry no anti seize.