Tip & How-To about Lexus IS
Lexus- How to Change your Spark Plugs
Tools Required or used to assist:
-3/4" (I believe, the normal sized one, not the huge one) spark plug socket
-Needle Nose pliers
-Flat head screw driver
-#5 Hex Wrench
-12mm wrench with closed end on one side
-Spark plug gap tool with wire gap checker
1. Buy replacement spark plugs. I bought Bosch Platinum+2 plugs for about $4/apiece from an online parts store, but from what I've read, the Platinum+4 are much better. They provide much more complete ignition and offer a noticeable improvement in mileage. One anecdote I heard was a friend of a friend who went from 20mpg to 24mpg on his BMW 3-series. The platinum+4 are only $1 more, so the possible performance improvement is well worth it.
2. Get your tools.
3. Remove the engine vanity cover by removing the three bolts near the base (front) of the engine. You'll need a hex wrench to get these out. See the picture below for location. Once the screws are out, rotate the Lexus logo 90 degrees and the cover should come off pretty easily.
4. Practice removing one of the easier spark plugs in the front.
5. First, disconnect the electrical connector from the spark plug tube head by pressing the end with your thumb and using a flat-head screwdriver to pry the connector off. Remove the spark plug tube screw using a socket wrench or equivalent. The tube should now slide out. See the picture below for reference. That was practice, now put it back in and replace the screw holding it in place.
6. Clean the area around each spark plug tube using a hand towel, pressurized air canister, or both. This includes the spark plugs behind the intake manifold. This will be tough because you will have to work by hand, but it is important.
7. Start by removing the most difficult spark plugs - in this case, the back ones. It is better to do the easy ones last, in case - for some reason - you give up or can't get the back plugs out. The back plugs are located behind the intake manifold (see picture below). You'll have to get to them through the opening indicated by the '''blue arrow. You can make this more accessible by removing what I think is the cruise control bracket. Loosen the nut indicated by the '''yellow arrow and remove the bolt indicated by the '''red arrow. Warning: these might be very tight.'''''''''
8. Repeat step 5 starting with the rear right spark plug (rear right when facing the front of the car), followed by the rear center, then rear left. When removing the spark plug, be sure not to let any dirt or debris fall into the engine. It could cause sever damage. The best thing to do is to remove the old spark plug, briefly inspect it, and immediately begin installing the new spark plug.
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Posted by Gale Todd on
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