Seized plugs

Honest John Back Room » The Back Room Archive
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Sat 10 Mar 2001 20:43
Seized plugs - Malcolm
What is the best way(if there is one)to remove the spark plugs from my sons 90 mitsubishi galant .They only seem to move approx.5mm then they are solid.I tried release-oil but i think it needs someones realy good tip to save me because you see i sold him the car!, which i now regret since he comes running to me whenever anything goes wrong, so please someone help met out of this situation.
Reply | Report as offensive | Link
Sun 11 Mar 2001 09:48
Re: Seized plugs - steve paterson
Check that the right plugs were fitted, you might be able to see the plug number on the ceramic bit. This will let you know what you're up against.
I've seen all sorts of combinations, washered plugs on tapered seats and vice versa, wrong reach etc. There is a possibility that the wrong reach plugs were fitted, allowing carbon to build up on the threads protruding into the chamber, making removal difficult. In any event use good quality tools with enough leverage, the cheap and cheerful stuff will not do. It really does make a difference. As a last resort I'd get the engine hot and try and remove the plugs in the same way that a thread is tapped, half a turn out, quarter of a turn back in, half a turn out and so on. It should be noted that alloy cyl. heads are normally worked on when cold, and are very easy to damage, but you're in trouble anyway.
Reply | Report as offensive | Link
Sun 11 Mar 2001 10:27
Re: Seized plugs - Adam Going (Tune-Up Ltd)
Steve's comments are spot on, but if it is the case that incorrect reach plugs have been fitted it sometimes helps to run some RED-X staright through the carb with engine running, as this can soften the carbon deposits around the tip of the threads. On a four cylinder engine around 100ml drizzled in over,say, five minutes should be enough without the risk of fouling the plugs. It will make the exhaust very smokey, but that will stop after 2-3 driving. Good Luck !!
Reply | Report as offensive | Link
Sun 11 Mar 2001 20:35
Re: Seized plugs - Malcolm
Thanks to all for the advice, have checked and they are the correct plugs fitted,will try the hot engine method and if that does not move them then they will just have to stay there and hope they last untill he changes his car. (it must have been me that put them in too tight).
Reply | Report as offensive | Link
Sun 11 Mar 2001 14:19
Re: Seized plugs - honestjohn
GREAT TIP FROM ADAM, BUT NO ONE SHOULD DO THIS WITH A CATALYSED ENGINE WITHOUT FIRST DISCONNECTING THE CAT OR CATS.

HJ
Reply | Report as offensive | Link