Its time for me to change plugs in the GT/4 for the first time so please excuse some basic questions. I've searched relevant threads but I'm still unclear on a few things. I have the tool that came with the car but I don't know if its the best one to use. Is there anything that I should be particularly careful about? Are there any questions that I should be asking but am too dumb to know? Thanks.
Not sure what tool you have. The front bank needs a little creativity to get at the plugs. Put a little anti-sieze on the new plugs, don't cross-thread them.
and if you do decide to use a combination of standard sockets and extensions, tape them together with a bit of insulating tape !
I use the spark plug socket that came with a Craftsman set I bought decades ago. It has a rubber insert that grips the plug when pulling it out, and, more importantly when CAREFULLY screwing one back in. Be sure to blow out the recess with the extender and dust cover removed before removing the plugs. You don't want some random bit of debris falling into the hole.
its been mentioned before but as I dont have the original spanner I use a short length of suitable hose to undo the plug (after untightening a turn with socket) and also to put the plug back in and screw it in (finishing off with a socket). The right size hose fits the ceramic of the plug snugly so it doesnt drop out on the way out and in, and when re-installing the plug you have the finger feeling of whether the plugs thread is properly seat before any real force is applied. I also do one at a time so I dont mess up the spark leads.
Thanks guys. It's better to blow away the crud as opposed to sucking it out with a shop vac? Pulling off the leads is a straightforward pull by the boot? The original tool has the foam insert and shows signs of having been used many times in the past so I'll stick with that. David
A shop vac won't lift all the crud out. You want air flowing through all the nooks and crannies, and a shop vac mostly just pulls air in through the top and then back out the hose. Compressed air will blast the crud out... of course it will blast it straight into your eyes, but if it's a choice between your eyes and your combustion chambers, that's an easy call
This is how I do the back bank. Spark Plug Removal Remove plug and extender. Drop in socket. Put extension in, snap extension into socket, then onto plug. Put socket wrench on extension and unscrew plug. Remove socket wrench from extension. Pull up on extension while pressing socket against socket hole wall in cylinder head causing socket and extension to separate. Pull out extension. Use telescopic magnetic pick up tool with pivoting head to pull out plug socket and plug. Spark plug installation. Drop new plug into hole. Drop in socket. Put extension in, snap into socket, then onto plug. Put socket wrench on extension and screw plug in. Remove socket wrench from extension. Pull up on extension while pressing socket against socket hole wall in cylinder head causing socket and extension to separate. Pull out extension. Use telescopic magnetic pick up tool with pivoting head to pull out socket. Place extender on wire and onto plug. It goes pretty fast once you have it down. Front bank is normal except for the motor stay for which I use a pivoting head extension to get around.
Yes there is a 308 specific tool that came in the tool kit. This is it. Makes life painfree. Image Unavailable, Please Login
GearWrench 80546 5/8-Inch x 6-Inch Swivel Spark Plug Socket - Socket Set With Spark Plug Socket - Amazon.com The magnet makes install/removal 10x easier than the old rubber plug style. The rubber plug slides off when you tighten the plug and you get to fish it out with needle nose pliers.
Or you can use this companion tool call a rubber hose. You loosen the plug and while it is standing proud you slip the rubber hose on and unscrew it out. I never use the rubber grommet in plug tools. Installation is also with the rubber hose. This way you can feel any resistance such as the start of a cross thread. No matter how abusive or sloppy you work with a rubber hose you can't damage anything. All the cross-threaded sparkplug holes I have seen were from pro mechanics working too fast. Sometimes it is the next mechanic that discovers the mistake and has to fix it. Image Unavailable, Please Login
Everyone knows you spin CCW first until you feel the threads click, then CW slowly to start, hand tighten, then torque. The rubber hose is better than the socket with rubber insert I will agree though...
Tool Roll Spark plug tool. It's hard to use in the front bank. I like the rubber hose idea because it's flexible so getting it into the rear bank may be easier.
38,000 posts and you are just now changing your first spark plug? That's amazing. Did you recently decide to start servicing the car yourself?
I spent a lot if time here researching before I bought. I've only had the car for eighteen months. When I bought the car I had it gone over by an expert and had him address all the deferred maintenance issues. The plugs were changed about a year ago but I've had some carb leaking that fouled them. Coincidentally to the purchase was a relocation that left little opportunity for me to do my own work. Now that we're settled I intend to get more hands on.
No one mentioned gapping the plugs so I will add that before putting them in double check your gaps unless your using a "new fangled hi-tech self-gapped" spark plug.
The most popular "new" type plugs are Iriduim plugs. The NKG website says to gap Iridium plugs to manufacture spec just like any other plug. NGK Spark Plugs USA - Gapping Spark Plugs 0.028" is a good number for a 308.
