has anyone experienced bosch super 4 spark plugs causing misfire? before christmas I had a bosch super 4 blow out of cylinder 4 resulting in a helecoil and new set of super 4's. yesterday cylinder 4 had obliterated another plug this time there were no prongs left on plug and no compression at all from cylinder 4 the garage have had my car for a day and half looking at it to try and find problem but cant without striping engine. thay are not charging me for looking at it. can anyone advise what I could do now if anything.



this six week old plug. whats left of it came out of cylinder four. the left plug is what its meant to look like

 

bosch s4s are not recommended in 170s use only platinums, could well as goosed the rings and damaged piston if not valves could be a very expensive repair

 

Plus 1, I would be very worried with that amount of damage to a plug. The metal has gone somewhere but also what could have caused the problems in the first place?

 

thank you 1-pd for your reply since I read your reply I done a little investigation and turnes out I have been miss sold these plugs from halfords thay are not for st170. damage caused by the super 4s has resulted in needing a new engine and injectors needing to be looked at. or worst case scenario scrap my st170

 

That is a major cock up caused by the wrong plugs! Hope you get it sorted out.

 

Bloody hell thats dreadful. Could you claim off them?

 

Zetec engines always run best on genuine ford plugs and leads imo. I have however never seen that!

 

If it was a turbocharged engine over boosting could melt a plug but its a strange thing to happen on a normal engine.

 

its unlikely any supplier could be held liable unless you have it in writing that they stated they are suited for the 170 and also then you would need a engineers report to back you up, but 170s should only ever be run on platinum plugs regardless of brand

 

Go in to halfords asking for plugs and record the response. Video walking into the store and then put the phone on the counter.

Do this before you raise a complaint.

 

im going to contact ford for written confirmation the plugs are not recommended for st170 I have pics of their instore book for ford focus. I tried to search online for halfords bosch super 4 for 2.0 duratec and a page came up and written at the bottom in light gray with a line through it 2.0 duratec missing.

 

You should be able to search by registration number on the Halfords website. The st170 engine is a zetec even though it says duratec on the cam cover.

I'm sure Halfords small print says to use their information as a guide only.

 

Go to Halfords and stick in your reg number in the parts finder and you get this for an ST170. No mention of Bosch at all



If you search by engine size i.e. 2004 Ford Focus 2.0 it does indeed recommend Bosch Super 4 plugs :

 

I have never seen on any database bosch s4s used on the 170, simply stated is they use platinum plugs only like OE,ngk, denso iridiums etc