spark plugs

[merc man]

hi there

I recently went to visit my grandad and he asked if i could service his little renault clio which also had the engine check light on, as i mainly service my own cars and have a scanner, i agreed and left my car at his and took his back to mine (where i have all my tools)

Anyway all has gone well but when i came to change the spark plugs two were easy to come out, but two are rounded off and wont come out, and they are the long deep engine ones that require the long smooth spark plug tool. When plugged in to my scannner a fault code comes up which is a cylinder misfire, which i think is down to the spark plugs, any ideas on how to remove the spark plugs? as i dont think he wants to pay main dealer prices.

 

[BlackC55]

Has the "nut" on the plug rounded? Or has the thread of the plug been damaged?

 

[merc man]

Has the "nut" on the plug rounded? Or has the thread of the plug been damaged?

the nut on the plug has rounded, i assume the thread is fine as they are in place

 

[BlackC55]

How did that happen?

Try and hammer a smaller socket on top of the plug and make sure the engine is hot as it will help if they are tight.

 

[merc man]

i have no idea how it happened, i know i did not do it, as i have serviced over 100 of my own/family/friends cars and the only problem i usually have is the sump plug! the car has been serviced by renault most of its life, and the dealership that he went to has now shut down. i cant get any smaller spanner on it as its the long socket type and the smallest socket of the range, which is at least 10 inches or so in the engine!

any ideas or do i have to strip the engine? or is there somewher i can take it to have them taken out?

The car runs at the moment and if anything it seems to accelerate better.
but its a very cheap car. Something my nephew said made me laugh, he said he could feel the road and asked if it was Fred Flitstones car!

Age is nothing but a number!

 

[grober]

old school mechanic?

How did that happen?

Try and hammer a smaller socket on top of the plug and make sure the engine is hot as it will help if they are tight.

You might also try a long "multifit" type socket which acts on the flat of the plug rather than the "angles". They are supposed to fit both a/f and metric sizes. HALFORDS used to stock them. Or you could try driving on a impact type socket as Black C55 suggested. Be prepared to destroy the plug/and or socket in the process! This is a job to possibly entrust to a highly experienced "old school" professional mechanic who has the tools and knowledge of what technique works in this situation. Shouldnt cost much since theres not much involved but the "wealth of experience" you will benefit from will be free. I have removed stubborn plugs from heads before now using a good fitting socket, 1/2 extension ,an impact driver, and a 5 lb hammer! Only works if you have a very good grip on the plug of course.

 

[Harley Man]

There are three things you could try:

1. If you were using a 12 sided socket try a good 6 sided one, snap on and Stahlwille do sockets that drive on the flat of the nut rather than the corners.
2. you can get special sockets to remove rounded nuts, my set are made by Irwin I think Snap on do them too. In order to use them you will need to break the top of the plug off, which means there is no going back at that point
3. You may be able to put an old fashioned box spanner on the plug and tack it to the plug with an Arc welder or Mig then unscrew it

Good Luck, its a real pain when people use the wrong tools and round things off

 

[merc man]

success

after such along time and so much mis-fireing i decided to sort it out once and for all, i went and got all the tools i could think of, and spent about 4 hours on it, but the best way i found was to put a larger long reach socket over the plug and fill it with hot welds let it cool down and turn! came off easy and i got both out and replaced with new ones! i think the coil/leads are gone but will replace them tomorow from euro, as well as finding a good clutch fitter!

thnaks to all for your help.