Introduction
Changing the spark plugs on Renault 5 Gordini and Gordini Turbo models is not entirely straightforward. Access to no. 4 plug is very poor as it is under the bonnet catch. The plugs are recessed within the cylinder head and require an extension in order to extract and refit them. It's rather difficult to fit the extension under the bonnet catch and use it to extract the plug.
General Method
Before you start: make sure you note down the locations of the HT leads, and which plug they go to. For reference, the firing order is 1-3-4-2, with No. 1 being the plug closest the flywheel (front of car). The distributor rotor arm rotates clockwise, so you can simply note the position of No. 1 HT lead, and from that and the rotation direction and firing order deduce the correct order of the rest of the plugs and HT leads.
The method of removing a spark plugs is to remove its cap from the top of the rocker cover and then extract the plug and extension.
The caps hold the terminals for the HT leads. The plugs have an approximately 3-inch long plastic extension onto which the cap is clipped.
I usually find that the spark plug extensions are quite loose on the plugs, so I can undo them with my fingers. The spark plug socket supplied with my socket set (Halfords Professional) can be turned upside down and the rubber grip pushed over the end of the plug extension. This can then be used to unscrew the extension. If the extensions are tight, pliers can be used to unscrew them. Sometimes even this is pretty difficult, but persistence should pay off! I once struggled to remove one extension for over an hour, but did it in the end...
Once the extension is removed, the plug can be accessed with a standard 10mm spark plug socket with an extension on it. It is practically essential that your plug socket has a rubber insert to grip the plug when it is removed. Otherwise, once you have undone the plug it will just sit in the recess in the head and you won't be able to pull it up.
Removing Plug No. 4
This is the difficult one! It's often neglected, so may be rather tight. When removed it may be in terrible condition, oiled and fouled.
I use the spark plug socket from my Halfords Professional socket set with the shortest of the 3/8" extensions. This is just long enough to be slightly below the top of the rocker cover so that a ratchet drive can be clipped into it. It only just works. A universal joint and another extension can be used if that helps.
Refitting The Spark Plugs
I recommend that the threads of the plugs are cleaned, then smeared lightly with copper grease. This helps them seal and makes them easier to remove in the future.
Make sure that the holes for the plugs in the top of the head are clean. Wipe them out with a rag, taking care not to drop grit into the cylinders. It's almost impossible to be absolutely certain that nothing at all is dropped into the cylinders, but I've not had a problem in 10 years of Gordini ownership...
Put the plug into your plug socket and hope that the rubber insert grips the plug!
For all except No. 4, attach an extension to the plug socket and carefully lower the plug into its hole. Tighten the plug carefully and slowly, checking that it "feels" ok as it starts to screw in. If it feels like it's going off centre to begin with, stop and re-check. The plugs are not fitted tightly. I think the sticker on the bonnet warns you to only tighten to 14Nm - that's really not tight at all. However, I find that tightening until it feels like the plug is "home" and then giving it a further quarter of a turn is usually just fine.
For No. 4 plug, put the plug in the socket so it's only just gripped by the rubber, but its head is sufficiently inside the socket to be able to tighten it.
You will need to withdraw the plug socket later, and if the plug is pushed right into it, you may not be able to pull the socket from the plug once the plug is done up, in which case, you'll have to remove the plug and do it all over again... Once the plug is loosely located in the socket, lower the plug into the hole, and then loosely fit your extensions into the socket, without putting downward pressure on the plug. Remember - you don't want to push the plug socket on too firmly!
