Some one doesn't post anything for ages then three come along at once :)

 

On Sunday the family and I were in the car.  We were tootling down a road when all of a sudden there was a weird sound, a sort of pop and bang combined. Straight after that the engine started making a sort of ticking which increased with acceleration and slight smell of petrol. As we were less than half a mile to our destination I tried to carry on but once we got on to a hill and more power was needed the noise increased so I decided to park up and investigate. My initial thoughts while driving was, has the manifold half dropped off?!

 

To keep a long story short. I removed the Ignition coil unit off the plugs and one dropped on the floor.  The spark plus had no side electrodes, (not sure when those went either down the cylinder or hitting the road).  Most of the the thread in the cylinder block was missing :(

 

 

After a few phone calls, I found a place that could fix it by putting an Insert in.  Anyway the good news is the Insert worked perfectly. The car is home and I am just waiting for a dry spell so I can do a flush and oil change. It was due at half-term but bringing it forward to get any extra 'bits' out. Of course any extra 'bits; might be in the Catalytic converter!

 

What caused it?  I guess I'll have to assume the plug was either over or under tightened, by me - user error. 

 

Any other suggestions? :)

 

----------------------------------------------------------------------------------------------------------

There has not been much to say on car front, until recently, two more post shortly.  Still going, after a lay up for a few months prior to and during part of lockdown.  The holiday we booked last year for this July in Scotland looked unlikely, but the place reopened 3 days prior to our booking date .  So, this car has now done a Scottish trip at about 1,600 miles each time there, back and touring about for three years.

 

Show us the spark plug too.

Two things can cause that.
Previously damaged thread.
Low quality spark plug threads

Thanks for the replies.  Got plug, is this clear enough.  No major deposits just 4 missing electrodes, Bosch Super 4, (I've noticed threads in the past about using these or not - perhaps not).

 

 

 

I'd guess the plugs have  been over tightened enough to knacker the threads. Was the insert a helicoil? 

33 minutes ago, VRS_White_Hatch said:

Was the insert a helicoil? 

 

Not a helicoil. They said a copper insert like 'Timecert'.  Said would be good for the remaining life of the engine. It's certainly done the job. 

 

It is my first step experience of a popped plug. 

Is it you that installed that particular spark plug?

or

Did the car had a previous owner and you never touched the spark plugs?

38 minutes ago, RicardoM said:

Is it you that installed that particular spark plug?

or

Did the car had a previous owner and you never touched the spark plugs?

 

Me further up the thread:  "What caused it?  I guess I'll have to assume the plug was either over or under tightened, by me - user error.  "

 

I'm pointing the finger at me, myself and I   I've done 3 or 4 plus changes on this car, so until the last change it was fine.

 

Interesting you mention the previous owner, I don't think he/she touched much at all

When inserting a s/plug always start it off with your hand and put a little copper grease on threads never over tighten in a ally head. 

27 minutes ago, mikefelicia said:

When inserting a s/plug always start it off with your hand and put a little copper grease on threads never over tighten in a ally head. 

 

Ooo, sound like a new topic starting here . 

 

I usually start with my hand and don't use any greases. I was under the impression that using things like cooper ease could leads to over tightening as the plug can get turned further in?

The most amazing part of this topic is the absence of ALL four ground electrodes. Initially I thought they were intentionally cut and filed.

Something is not right...

How many miles has that spark plug? Also, the exact spark plug type?

15 hours ago, Another_Felicia said:

Thanks for the replies.  Got plug, is this clear enough.  No major deposits just 4 missing electrodes, Bosch Super 4, (I've noticed threads in the past about using these or not - perhaps not).

 

 

 

Looking at the fracture points, right by where the electrodes are welded to the rest of the metalwork, I'd say they have fractured in response to impacts possibly during the final stages of its 'escape' from threaded attachment.

26 minutes ago, RicardoM said:

The most amazing part of this topic is the absence of ALL four ground electrodes. Initially I thought they were intentionally cut and filed.

Something is not right...

How many miles has that spark plug? Also, the exact spark plug type?

 

Yes, I could not believe how tidy the remains of the electrodes looked. 

 

According to the Odometer - none  . That's another story. About 8k miles. Bosch Super 4 FR78.

 

it will be Champion RC89PYC next time.......

 

 

28 minutes ago, Wino said:

Looking at the fracture points, right by where the electrodes are welded to the rest of the metalwork, I'd say they have fractured in response to impacts possibly during the final stages of its 'escape' from threaded attachment.

 

I was wondering that. Removing the Ignition coil I wasn't expecting a plug to move so I just couldn't catch it in time before gravity took hold. bouncing off the engine under skirt then the floor.

I dont think slightly under or over tight plugs can cause this failure that most likely seems like a crossthreading situation

26 minutes ago, Thefeliciahacker said:

I dont think slightly under or over tight plugs can cause this failure that most likely seems like a crossthreading situation

 

Could well be. 

I'm putting this one down to experience.  If it takes as long to happen again, as between the first time I changed plugs and this week, I'll be 15 years into paying for my T.V. licence.

5 hours ago, Another_Felicia said:

 

Ooo, sound like a new topic starting here . 

 

I usually start with my hand and don't use any greases. I was under the impression that using things like cooper ease could leads to over tightening as the plug can get turned further in?

 

Btw, I missed a sentence.     Not that it has done me any good this time round

15 hours ago, Another_Felicia said:

I usually start with my hand and don't use any greases.

So you're constantly in pain from sore skin

29 minutes ago, RicardoM said:

So you're constantly in pain from sore skin