SPARK PLUG JUST POPPED OUT-HELP!!!!!!

Post Sat May 20, 2006 3:25 am

Poodling along the road 25-30mph...
Strange sound from engine....slowed down...
Turned off radio.............
Slowed down more....
Tick...Tack...Click....Clack...Tick...POP...POP
Pulled over...engine Barely Alive!!
Engine off...bonnet up......HT Lead

NO SPARK PLUG!!!!!
FOOOOKING HELL

What is all that about....got the AA...managed to get another plug from garage...screwed it in....but wouldnt tighten up fully....managed to get it tight enough to get home....felt the lead and it was loose again....is this expensive...does anyone no this is a common fault with the M20...i just hope it hasnt been cross threaed at some point...Jeeeze, i get it serviced at munich ledgends...have spent over a Ã‚£1000 with them...normally she doesnt miss a beat and hasnt in 16,000 miles, started everyday.

HELP PLEASE!!!!

Post Sat May 20, 2006 7:17 am

That does sound like its been cross threaded, for me it would mean a new head!

Andrew

Post Sat May 20, 2006 8:06 am

its probably been overtightned and stripped the thread for the plug your probably looking at a new head mate

Post Sat May 20, 2006 8:12 am

You should be able to get the thread re formed using a heli-coil, ask a few engine refurb places to see if they will do it with the head on...

Post Sat May 20, 2006 11:06 am

I'd get Munich Legends to fix it with a heli-coil.
If they were the last ones tightening it up...
... it is down to them.

Post Sat May 20, 2006 11:27 am

I would certainly have a word with Munich Legends if they changed the plugs.
May not be their fault. Sometimes it's impossible to get a seized plug out without it stripping, or maybe it was already stripped.
Should be possible to helicoil the thread with the head in situ. Technique is to put the piston part way down, then fill the bore wirh grease. Any swarf will fall into the grease and be pushed out the plug hole when the piston is put TDC.

Post Sat May 20, 2006 3:10 pm

when u change a spark plug it should tighten up. if it fucks up on the way out (shouldnt happen unless they have been in for years) then the mechanic should have definatly told u at the very least. it is 100% the responsibility of the workshop now. they should have told u they made a mistake. the truth is they probably let the apprentice do it and stuffed it up. it is fixable anyway just go back and make them fix it. i wouldnt be payn em myself but thats up to you.

dont let these guys freak u out you definatly dont need a new head!!!

oh and check it to make sure its fixed when u get it back they might try to do some cheap dodgy fix.

we had an e34 come into work one day makin a terrible noise runnin on 5 and poping out of number 6. the spark plug was stuck in the end of the lead. i didnt change the plugs on it but i just tightened it up and it was fine. maybe its a strange m20 phenomenon.

Post Mon May 22, 2006 2:21 pm

Dont be too quick to aportion blame remember the age of your engine and how many times the plugs have been removed before. The threads could very easily have been partialy damaged for a long time, every time a plug is fitted or removed thread deteriorates (SOFT ALLOY TO STEEL, STEEL WINS.)

You should be able to have plug hole heli-coiled okay.

Do not use grease when heli-coiling, Grease does not help the thread cutting process and could make matters far worse.
The soft alloy swarf will do no harm at all, just blow out with air line and start engine up, engine will blow it out.

Post Mon May 22, 2006 6:00 pm

Gt6s wrote:Dont be too quick to aportion blame remember the age of your engine and how many times the plugs have been removed before. The threads could very easily have been partialy damaged for a long time, every time a plug is fitted or removed thread deteriorates (SOFT ALLOY TO STEEL, STEEL WINS.)

You should be able to have plug hole heli-coiled okay.

Do not use grease when heli-coiling, Grease does not help the thread cutting process and could make matters far worse.
The soft alloy swarf will do no harm at all, just blow out with air line and start engine up, engine will blow it out.

a, so swarf in the chamber will be very good for the bores and the top of the pistons me thinks........

an air line is not going to blow it out either, just wedge it all where it shouldn't be

Post Tue May 23, 2006 2:56 am

Many Many Thanks!!! Will get onto Munich today, needs an oil serivce, so will get them to quote me for the heli coil. great, just what i need, another bill. thanks again .

Post Tue May 23, 2006 9:55 am

Simon13 wrote:
Gt6s wrote:Dont be too quick to aportion blame remember the age of your engine and how many times the plugs have been removed before. The threads could very easily have been partialy damaged for a long time, every time a plug is fitted or removed thread deteriorates (SOFT ALLOY TO STEEL, STEEL WINS.)

You should be able to have plug hole heli-coiled okay.

Do not use grease when heli-coiling, Grease does not help the thread cutting process and could make matters far worse.
The soft alloy swarf will do no harm at all, just blow out with air line and start engine up, engine will blow it out.
a, so swarf in the chamber will be very good for the bores and the top of the pistons me thinks........

an air line is not going to blow it out either, just wedge it all where it shouldn't be

All right Totally 100% correct method is to remove head !
If you have ever left a car in to have plug thread heli-coiled I would be suprised if they allowed you to watch.
GREASE IS NOT USED ! If you had ever used a tap and die set you would know that grease is a heavy lubricant not a cutting agent. The purpose of using a cutting agent or light lubricant is to clear the tap of swarf and to cool the cutting edges. If you put grease near a tap it will not cool the tap as it has no flow, the swarf builds up in the grease, again because of lack of flow to clear swarf, this clogs tap solid destroying the new thread. TOTALLY DEFEATING THE OBJECT OF EXERCISE.
A clogged tap can also cause tap to jam solid and even break in plug hole. YOU WILL BE LEFT WITH SCRAP !
Running engine will sucessfully clear swarf. REPEATS, The soft alloy swarf will do no harm at all, just blow out with air line and start engine up, engine will blow it out.

Post Tue May 23, 2006 11:43 am

I don't think anyone said that you should use grease as a cutting compound. Just put some on the top of the piston to catch the swarf.
That was my understanding.....

Post Tue May 23, 2006 11:54 am

Morat wrote:I don't think anyone said that you should use grease as a cutting compound. Just put some on the top of the piston to catch the swarf.
That was my understanding.....

Fill the bore were the words used. Personal opinion, totally pointless exercise. And could cause a very nasty hydraulicing situation. ie blob of grease in inlet port (engine tries to compress a fluid which can not easily be compressed) YOU DONT WANT THAT SITUATION!
Neither can can you afford to get grease on the tap, use either cutting agent or light lube.
Ideal world, remove head. NO ARGUMENT !
Real world, turn engine over with plug out will blow swarf out, run motor will blow out and also burn swarf.
Way it's done.