Other than removal of the two 13mm bolts behind the intake manifold, the job was relatively easy. I think my excessive writing and description makes the job seem harder than it really is in reality. My intention was not to discourage you to attempt this job, but to make you better informed and prepared for possible problems. Unlike other Lexus vehicles such as my ES300 2000, the 2008 RX350 requires the removal of the intake manifold. The sharp angle of the rear plugs, tight space, and brackets overlying the inductions coils make it impossible to remove the induction coils and plugs without clear access. This is clearly why my local Lexus dealer wanted at least $500 to complete the job. It might have been cheaper to have the job performed at the local Toyota dealer. Let me know if you have any questions. I was able to change the spark plugs on my ES300 2000 without removal of the intake manifold or throttle body. Be sure to only attempt the job with a cold engine.
Anyways, Lemex, my wife and I love to go to Mexico. We especially love to go to Tulum and Cabo for vacation. I have even traveled to Merida to visit family. I found your original write up on changing your spark plugs to be very helpful.
I just had a seven hour battle with the 350. The majority of time was working with the back left bolt for the intake manifold. I knew that once I got it off that I would have a very difficult time getting it back on. The problem is the wiring harness for the injectors and where they are situated against the firewall. The route for the wiring harness sits directly behind the bolt and has zero to zero wiggle room. I lost the battle with the bolt. I decided that after working with this bolt for four hours that I should go ahead and put the car back together. I figured that with one bolt in the back of the manifold and four others on top with two additional nuts then hopefully there won't be any problems. I feel disgusted that I couldn't put the car back together properly but I honestly don't know how I could have done it without removing the wiper assembly.
I studied your post for quite some time before I started the work. I also went to Sears and purchased the 13mm FlexHead Gear Wrench. Apparently the 07 models have 12mm bolts and I had to take my kids car back to Sears. No problem, I should have checked before I made the purchase.
Your thread was very helpful and if you or any others have advice for the bolt I have not returned to the back of the manifold, please comment. I would hate to have to take this vehicle to the dealership for instal.
The dealership claims that the factory plugs are good for 100,000 miles and they wanted $14 per plug. I believe the cables you're referencing would be considered the ignition coils. Each coil costs about $114 unless you get them for cheaper on line. I'd read too many bad reviews for coils bought other places than the dealership so I stayed with Toyota OEM with a one year free replacement in the event of defects.
I would like to know what parts have to be replaced when changing plugs. Specifically, do the intake manifold gaskets and the throttle body gasket have to be replaced when attempting this and are there any other parts that should be changed at this time?
Your detailed instructions saved the day. An amazing post with instructions that even this amateur could follow. I used it to replace a the #1 (back left, or closest to passenger) ignition coil. I definitely could not have done it without your post. The dealer quoted me $640 and all I spent was the the price of one ignition coil and about 3 hours.
I encountered a few things probably due to my amateurism. Hope I can help others.
Following your instructions:
1. I removed the left side engine cover by using wire cutters. With jaws open the two cutting blades slip under the top of the plastic clip, brace against a block or pliers and pry up they come out easily. (Don't close the jaws were not trying to cut the clip!)
3. As mentioned by another post, in the 2007 these are 12mm. In my case it is important to note that after trying desperately to find the back left bolt, I finally discovered that the Lexus dealer had left it off last time. In your pictures of the bracket blocking ignition coil 1 & 3 the long silver aluminum bracket is there to hold the ignition wiring. The bracket for our infamous back left 12mm bolt is at the very left of the picture and dark in color. If it is not being used (as you mentioned), one can actually remove the lower bolt and take the entire thing off permanently, which provides greater access to ignition coil #1.
9. I really couldn't get the ignition wire off with my hands. I took the 10mm bolt out so that the ignition coil could be raised by half an inch or so, turned the connector towards me and grabbed the back with needle nose pliers, squeezing down on the release with the top jaw and the bottom of the connector with the bottom jaw, being very careful not to grab any wires. Came off easily now. There is basically almost no room for the ignition coil to come out. You have to carefully use the long rubber housing at the bottom to bend around the corner and get into the socket.
I just helped my ex wife change the plugs and the rear three coils on her 2007 RX350. The two bolts referenced in step 4 as 13mm bolts were 12mm on her car!!!!!!!!!!!!!! Just figuring that out wasted a good hour or so.
After wrestling with the bolt from hell on the left side, we found it much easier to just remove the wiper assy and the cowling, I have no idea how it can possibly be done with removing them. Overall the job took us quite a while mostly because I was trying to teach her how to stand on her own two feet, but we got it done!