R53 spark plug blown out!

[Neal500griff]

Hi,

Wondering if anyone has had this experience?

Driving home yesterday in my 2003 R53 Mini Cooper S, sudden banging sound from front end. Still drivable but managed to pull in to lay bye, popped bonnet with engine still running, could see spark plug extender had popped up above others and that’s were noise was from, obviously spark plug to number 2 cylinder had blown out. Was near my local garage so managed to limp there so they could investigate.
Spark plug had indeed popped right out but thread on plug itself seemed in damaged. Mechanic inspected but couldn’t really see as obviously thread in cylinder head is deep below top of engine. He did though manage to refit the spark plug and could tighten to correct touque?
Car restarted fine but engine management light now on (going back to garage to sort that in next day or two)
Just wondering if maybe plug had worked loose and unscrewed itself over time or whether it had blown straight out, which seems not as guess if that had happened wouldn’t have been able to screw back in?
Anyone any thoughts?
Hoping it’s just worked loose so don’t need to spend circa £800 on having the head taken off and reconditioned/replaced! Have heard you can get “time sert” inserts that retread hole with head insitu. Sounds risky to me, surely would leave dwarf in combustion chamber?
Anyone any experience or know a garage that can do inserts... or might it just be ok now it’s refitted and properly torqued up?

I’m in merseyside

[E-bmw]

It is not unknown on these, you should check all are correctly torqued up & check them occasionally.

[Neal500griff]

Thanks, yea, mechanic torqued up the others when he fitted the blown one.
What I need to know is if the treads damaged?

[E-bmw]

Neal500griff said:

Thanks, yea, mechanic torqued up the others when he fitted the blown one.
What I need to know is if the treads damaged?

Can't see that from t'interwebz mate.

[C-J]

Neal500grif said:

Hi,
Wondering if anyone has had this experience?
[stuff]
Anyone any thoughts? Have heard you can get “time sert” inserts that retread hole with head insitu. Sounds risky to me, surely would leave dwarf in combustion chamber?

E-bmw said:

Can't see that from t'interwebz mate.

Sorry chap, I'm not going to be much help - my only similar experience was years ago (and on a much simpler carburetor fed engine) when a plug came out of a cylinder. I was able to reinsert but not fully seated. It did run fine for a few years afterwards though. So at least yours reinserted ok.

ps: Following your description above, can you not get that wee little fella in the chamber to tell you what they see?!!!

Edited by C-J on Monday 8th March 17:44

Edited by C-J on Tuesday 9th March 11:06

Edited by C-J on Tuesday 9th March 11:09