Thread: Disco3 Spark Plug Question

Hi All,

This afternoon I got my hands on some new spark plugs for my 2007 Disco 3 4L v6 and decided to change them over. I do basic car servicing myself.

Besides access being a a bit of an issue, I installed three new ones on the air filter side of the engine and thought I would fire up the car to see if everything sounded ok. The car sounded a bit rough so I took off the leads and pulled the plugs. What I noticed on the plugs from the back two cylinders were that they weren't sitting in as tight as the front cylinder. Once the plugs were extracted it look clear that they hadn't fired and also that the electrodes were bent over.

Not sure what is going on here. I have installed a few spark plugs in my time with no issue. I have noticed I can't hand screw in the plugs 80% of the way and there are a few stiff points but I am confident I've seated them ok before starting to screw in. To answer the obvious question, I thought they might have been bent on purchase so decided to test and put in the old ones. I did about a half screw in and pulled to check and again the bending had started to happen on the old plug. The old plugs were not extracted with any bending.

HELP! Being nice to the car and a bit of maintenance has turned into a huge freak out!

From what I have read it sounds like either your plug socket hasn't got the little rubber insert in it to protect the top of the pug when you are using it or you are putting too much sideways pressure on the socket and doing the damage.
Have a look inside the socket you are using on the plugs to see if there is a little rubber insert in it ( in the top of the socket) and if there isn't one there get another socket, If there is the insert in there change the method you are using to insert the plug so that you are Not putting any sideways pressure on it and also make sure that the socket is FULLY seated over the spark plug.
I hope this helps