sub786

Folks I am adding my DIY exp in this new post. But it is up to the mediator if he wants to remove it as I also posted under another post. Thinking to help those who want to know if changing the spark plug can be done without removing the intake so posted under new post with a searchable Title without removing the intake.


Update on my project: On Friday night I changed all sparkplugs Here is some information that might help others

- REMOVAL of Panels: No need to remove the air intake panel. It can be done while it is on. Remove the airbox and air ducts to the Throttle body. No need to remove the throttle body. Remove the support bar holding top end of the struts. Remove the plastic panel exposing the wiper motor. You can remove the metal but I did not remove it. I disconnected the battery ground terminal.

- SPARK PLUGS: Purchased from NAPA Denso Iridium IKH20 (5344). I did not adjust any gap. It says .4 mm on the Denso box. Research said .4 to .44 and some say .44. I do not think the .04 mm difference ( Note.05 mm is regular printer paper thickness) will make any significant difference if it does then something wrong with the ES350 computer or airflow if it stalls. Though I checked with dial tool gap check it was around .41 to .43. I took as it is from the Denso box make sure all are the same. So the point is I do not want to stress myself with .04 mm difference ( Denso box vs Google)

-DIFFICULTIES: As we all know the 3 close to the firewall is the challenging ones. It took 95% of my total time vs 5 % front 3. Make sure not to rush and you must have at least 6 hours. I do not want to open the panel as I do not want to disturb seals that were bone dry for both the throttle and the intake. Also, you need multi-point spark plug removal. I have a magnetic sparkplug tool which helped. Also, you need multipoint extensions. To me, there is no set number as all 3 at back need different maneuvers to remove. So good to have multi-point junction connectors. Also, track the harness wires all the way to the front under the airbox close to the engine and try to make them loose by disconnecting a ground wire you will find out when you track the harness wires. This will give you some slack to pull the harness more up. Also, you might need to disconnect the 02 sensor wire at the back as it is covering the sparkplug close to the driver's side at the back. That is the hardest one but doable with some struggle

- CLEARING the harness: You need to find some hooks to pull up the wires I used elastic hooks from Harbor Freight. Also, I removed some ties holding wires to give room for the elastic band hook to pull wires up. Note you will not get space without losing the harness ties. Also, I broke all the clips of the harness going to the ignition coil so good luck. After 12 years it will be a miracle to save those. But the good thing is they still snap tight. I will keep an eye, if anyone gets loose I will see what are options but for now. they are good. I can also apply a touch of the black gasket on the top if it gets loose

- REMOVING the ignition coil: all ignition coils are held with one small screw. Easy to remove but after that pulling out the ignition coil needs a flathead long screwdriver (in my case) to pop up then they are easy to come out except for the back close to the driver's side as the harness wires obstruct it. But with a little more pulling up the harness wires on that side I was able to pull the ignition coil out. Note last part of the ignition coil is rubber so can be bent so I pulled it out and bend little to remove it. Note I did not replace the ignition coil as they look in excellent condition with no oil and bone dry. Also genuine are very expensive and my experience with that ignition coil is genuine and last extra long. I used to have another es which went all the way to 240K and still was running well when I sold it. Never changed the ignition coil. Also as I know how to do it if misfires I have a computer to run diagnostics and can change within a day. So in my case, I am ok with that. But if you want to change go for a genuine one as aftermarket can go bad with no guarantee.

- REMOVING the spark plugs: With multiple joint magnetic spark plug tools it worked.

- SEAL CHECK: No oil in the sparkplug area except in the thread ( some dry oil coating on the thread) which I believe is normal as it is coming from the cylinder. Checked the valve cover seals all looked good. Note if you are planning to change valve cover seals then you need to remove the intake. In my case, as they were bone dry so I did not remove the intake panel.

- INSTALLING Spark Plugs and Ignition coils: Did not adjust any gap I took the same as .4 mm from Denso. Applied anti-Seize greez to the sparkplug thread ( 1/3rd of the thread close to the point rest it will take up as you thread, I did not overapply). By the way, I cleaned just in case the ignition coil with brake cleaner for any dust. I sprayed in the hole where the sparkplug heads go in and then using the air compressor pressure dried it. If no air compressor air-can be used. It evaporates quickly anyway. Check the ignition coil seal in my case they were soft. Connected the ignition coil connectors and screwed the coil. Also made sure I installed the intake bracket at the back over the spark plug number 1. Then made sure all harnesses are back where they were. Zip-tied as needed.

- FRONT 3 spark plugs: Completed within 30 min.

- AIRBOX interesting extra filter: I believe ( after researching) a charcoal double-layer filter is for absorbing any water vapors in the rainy season and for the gas smell. It is really thick so I believe it can obstruct flow. I removed it and used just K&N filter. Installed back the airbox and all vacuum lines. And installed back all the panels. Took me around 6 hours.

STARTING: The first start missed, after that no issue. Hooked up the scanner and cleared the code as a result of the first miss start. Drove around 100 miles since the last change on Friday. Rechecked again today no codes and all is good.

Above is my DIY which worked for me. I wonder how much the dealer charge should be between 500 to 1000 K . I spend 80 dollars for spark plugs from NAPA that's it and all my free time. I will post if any changes or and also longterm results as time passes. But one thing I noticed I feel more punch in HP might be due to the new sparkplugs and the removal of the extra air filter combined effect. Regardless it sounds better. Anyway, all is good in the end for now.


AIRBOX extra charcoal filter: Just for knowledge link here.