Bosch plugs go boom! :(

[MacMan]

My father has a Lincoln Mark VIII with the DOHC 4.6 in it. Last week he looses a cylinder. We pop the hood to check everything over. Can't find anything initially. I'm thinking maybe one of the coil packs is bad or something. While I'm checking those, he's pulling plugs. Take a look at what he finds... not good. The top of the piston is scarred and the plug wire burned through (apparently because it wasn't able to deliver a spark to anything). He sent Bosch the pictures... still waiting for a response.

My tuner said that last week he also got a mustang in with the same problem. The mustang lost the engine... so just an FYI for those of you running Bosch plugs (if any). Might wanna use something different.

 

[blacksnake1960]

Try the Boch Plat plus 4s. I have run them for 2 years and I wouldnt trade them for any plug on the market.

 

[lightninmike]

call me crazy but i think something is missing

i actually have those in my stang
i should have kept the +4s those seemed better to me as far as response

 

[NastyWS6]

Damn, I'm kind of curious to see what bosch would say about something like that.

 

[TK94Bird]

I sell more bosch plugs then any other brand we carry combined. People really like them and i have never had any complaints on them. Of course thats just my experience on them, i would not mind seeing what they have to say to you either.

 

[shadow]

I had a bosch plug gernade on me in my Pontiac. It didn't take the piston with it, but I won't buy them again.

 

[MacMan]

Over at the Corral, I had a guy tell me that the same thing happened to his buddy's Escort, and he did loose the engine. Bosch said "oh well."

 

[03Sssnake]

Are this was not caused by the motor??? ...Mechanical issues, and or tuning issues usually cause damage to the plugs. Like fouling, sustained pre-ignition that resulted in melting, detonation damage etc.....

 

[Sinister Angel]

I have +4s running in my car no problems.

 

[i8u]

:uh oh:

 

[MacMan]

My father got this reply today:

Bosch invented the sparkplug over 100 years ago and produces over a Million plugs per day, In most cases it is determined that plug failure is caused due to improper installation of plug. (over torque during install) In your case by looking at supplied picture it appears that the other plugs where working properly, So it appears that over torque during install could be the case. As stated in a previous E-mail, our warranty department will contact you to send the plug in to be tested to determine why the plug has failed. If it is found that the plug was in fact defective Bosch will cover cost of any damage that occured.

 

[FordSVTFan]

Wow Bosch is almost sounding like a stand up company. I kind of bet they will determine it was owner error though:-(

 

[MacMan]

Yeah, exactly. What do we do when they say, "hey, it was your fault." Bend over and pay the $1200 repair bill, that's what.

It doesn't make logical sense for overtightening to cause the ceramic part of the plug to come out! Besides, I'm 95% sure that none of the plugs were over tightened.

If Bosch actually looks at that plug and decides to pay for the engine damage, I'll feel that they responded properly. But I still won't ever buy Bosch again.

Between about five different forums, 8 people have responded to this post by giving their own bad experiences with Bosch plugs. Not one person has said anything about experiencing similar problems with ANY other brand of spark plug.