Don't use Bosch sparkplugs

I replaced my sparkplugs with Bosch Platinum plugs. Within a month my truck began missing terribly and got to the point it wouldn't go 40 mph. Took it to the shop thinking I had MAJOR problems. Turns out it was the plugs and 1 coil pack. Now my Taco is running great again with 320,000 miles. The mechanic told me to never put Bosch plugs in a Toyota or Honda.

 

It's amazing how just the make of a spark plug can shoot the whole works down the tubes.
So even though they fit - something is just compatible with the yota motors.
Maybe they are not resistor plugs ?

 

I've heard that too. But I put some Bosch plugs in my brother in laws Sienna....probably 50k miles ago. No issues.

Is it possible that the coil was really the problem?

 

It's possible they weren't the right length. Which ones did you buy?

Also you said a coil pack went out, that could have been the source of the problem, not the plug.

Did your mechanic give you specific reason not to use Bosch?

 

I just stick with Denso irridiums

 

Did it just sound like it was running on 5 cylinders if a 6 banger or 3 if a four banger ?

 

If you think their plugs are bad you should see their CP4 HP diesel pumps.

 

Probably the wrong heat range.

 

Duly noted.

I also bought denso iridiums. They seem to be working ok.

 

It can be the exact listing and they still won't work. They are shit for Toyota. I've seen this issue with 80's 90's and 00's Toyotas including my own corolla.

It's denso or NGK 100%

 

I had to go look out of curiosity. These for my wife's 2013. Yep Denso but I don't think iridium.

 

I use the factory replacement NGK copper and change every 30k.

 

I didn't like them in my older Chevy either. I haven't even looked at a Bosch platinum in years, but years ago after just 25k miles that little electrode is down inside porcelain, you cant even see it.

 

Why even go with anything besides what the manufacturer uses? These are $4 a piece, and you only replace every few years.

not worth the hassle of trying another brand

 

Iridium vs. copper is really just a longevity thing. You're not getting any "stronger" or better spark with different metals or conductor arrangements. As long as it's gapped correctly, you're good to go. With copper conductors you will just be replacing them sooner.

 

Understand that. I just replace the first ones at 50k miles and they were worn some but not terribly bad. This set is for 100k miles change. I believe they are copper then, I just asked for original replacement. I haven't even looked to see if my 3rd gen comes with iridium. Edit to add; on the first gen I replaced them about every 30k miles. They looked practically new at that interval so I stretched these to 50k looks good to me.

 

yes, what he felt was the coil failing. But the mechanic is right, German plugs are for German cars

this

 

In all fairness the CP4 pumps were designed for European markets which have a higher sulfur content than in the USA. More sulfer equals better lubrication.

 

I'm well aware of the sulfur issue. As far as Euro markets, the pumps were used by each of the Big 3 in their HD trucks which were marketed & sold in the U.S.. New HD diesel trucks aren't cheap, yet there are quite a few folks who spent a small fortune only to have their truck go south due to pump failure. Costing them time & causing them aggravation. Fighting denied warranty claims. Lost wages if they needed their truck to earn a living. Ruined vacations if they needed their truck to tow their trailer. Perhaps those circumstances don't fall under your definition of "fairness".

 

German made Bosch spark plugs worked great in older europen vehicles. It's been awhile since I've looked, but I've heard Bosch has done what a lot of other mfgs. have done and moved a lot of their manufacturing to China.
While they may not be ideal for Asian vehicles due to the Made In China thing, I too suspect the bad coil mentioned above was as big or bigger a culprit than the Bosch plugs.