I'm going to do this job in a couple of weeks. It's a good time to throw new plugs in if you haven't changed them in a while. As long as you jump in and take the stuff that's in the way off first it shouldn't be too bad. Take off the cowl and air tube with the top half of the air filter box. Then go after the upper intake. Those are the big three obstacles, once you get them out of the way it's fairly simple.
When installing the rear valve cover, it's easy to roll the new gasket out of it's groove when wrestling it over the camshafts and in between the engine wiring harness. You won't know it until start up and find a puddle of oil on the ground.
Here's what I do. First, I like using Toyota F.I.P.G. (black RTV sealant)
I clean the V/C real good with brake cleaner, then apply sealant in the groove all the way around the cover.
Now set the new gasket in there and let it set up 15min.
Then clean the head real good and apply sealant to all the corners of the cam bearing caps. (removing all the old sealant)
I take out the half moons on the head surface and reseal them too.
I like to apply and additional dab of RTV in the U shape on the left back side of the head surface.
Now set your V/C on very carefully, (an extra pair of hands is recommended) and bolt it down.
Those bolts will snap if you over torque so use a cris-cross tightening sequence and don't over do it.
It's not a job you want to do over, trust me!
I don't know if they have the cowl removal issue but the intake removal will be identical. If I beat you to this repair I will post a photo guide. The only caveat to that is I have tendency to delete my hosted pics so I can post new ones.
I took a series of pictures of this job on my 2003.
I removed the winshield wiper cowl....the black part that is in between the windshield and the hood.
Removing the upper intake manifold requires you to have a 8mm HEX bit, so make sure you have that before you start, to save a run to the store to buy one.
There are COOLANT lines that connect to the throttle body, so you might want to drain a little coolant from the drain on the radiator, passenger side back side.
Be prepared for some coolant to drip as you work with the coolant lines on the throttle body.
The upper intake manifold is supported at the REAR, my pictures show where the bolts are, and the sizes of them (yes, there is more than 1 size bolt to remove back there)
I replaced the upper intake manifold gasket, don't know if it was necessary, but I did.
I also replaced the spark plug tube seals (part of the Felpro valve cover gasket set that I bought).
I would strongly recommend that one replace the FRONT valve cover gasket FIRST so that you know that part of the job before you have everything apart and are trying to lean back and see what you are doing with the back.
I did the front and back on separate days.
For spark plugs, use the spark plug that TOYOTA lists for YOUR year, different years use different plugs (within 1st generation with the same 1MZFE motor).
They should list a DENSO and a NGK number in your owner's manual, use either one.
You do NOT adjust the gap on the spark plugs.
Your pics on this job are pretty good. I was wondering about the thermostat change that you did. What brand thermostat did you put back in? My original thermostat has been doing it's job for over 200,000 miles and I don't want to put in a cheap 20,000 mile part. I think that I may purchase that part at the dealer. It's a simple part but it's very important.
I replaced the thermostat because it started regulating at 165 degrees, instead of the 180 degrees.
My father commented that about 2 weeks before I bought the van from him that the heat did not seem "as hot".
I connected my Scangauge to the OBDII port and determined the 165 degree issue, the replacement regulates at the correct temperature.
I bought a TOYOTA part, and highly recommend you do the same.
I have found that TOYOTA parts are very often very competitive in price as compared to aftermarket.
Some parts are best replaced with OEM ONLY.
If you change yours, don't do what I did and damage the front oxygen sensor ($$$).
Undo the zip tie that holds the radiator hose to the pipe that connects to the thermostat housing.
I did not....and when I pulled the hose free....it tugged on the wires on the oxygen sensor....and damaged the heater inside the sensor, so I had to replace the sensor.
Also, it is hard to see and get at one of the bolts for the thermostat housing, so patience is needed.
You may notice in the pictures, I replaced the "O" ring gaskets for the pipe as well as the thermostat gasket.
I was thinking Toyota parts. This van has been so reliable it seems very foolish to use any parts besides Toyota. In the last 10,000 miles my valve covers have started leaving drips in the driveway. This is the first leak that I have encountered in 200,000 miles.
For the valve cover gaskets, I bought Felpro "PermaDry" "molded rubber" gaskets.
They are a good brand.
Also, when I "removed" the upper intake manifold, I did not disconnect everything, I only disconnected what I needed to in order to move it aside enough to get full access to the rear bank.
As you will find, there is a LOT to take apart and disconnect, and I did not want to have more than necessary to put back together.
I had no need to lay the whole upper intake manifold outside the vehicle.....just needed to move it aside.
In 2003, they went to the metal, screw in style of PCV valve.
Older years will likely have the traditional style that presses into a grommet at the same location as mine.
In the UNLIKELY event that you find the "Gelling" issue, sludge in the area under the valve cover, you may need to buy NEW valve covers.
New valve covers would be needed if the space between the top of the valve cover and that thin metal baffel, that you can see in my pictures, is clogged with sludge.
The baffel is spot welded in place....so cleaning out the area above the baffel and below the top of the valve cover is not going to work out.
Having that space clear is CRITICAL as the fresh air comes in the FRONT valve cover through the breather tube (filtered air from the flex hose that goes to the throttle body) and contaminated air exits through the PCV valve.
If the area between the baffel and valve cover is clogged, your crankcase cannot "breath" and harmful chemicals/contaminates will build up in your oil....causing it to break down and give you sludge.
It is unlikely that you will find a serious issue, but if you do, a major step in cleaning it up and KEEPING it clean would be new valve covers.
I don't want to scare you, just trying to cover as many bases as possible.
You will see that there is some "varnish", dark deposit, on the inside of my valve covers.
As you can see in my pictures, I cleaned this up, however, it was not causing any problem can could have been left there to no ill effect.
Sometimes people get concerned about light deposits....There is no need as it is not an issue.
A light varnish deposit in there is not at all unusual, and is normal...certainly by your 200K miles, glops of sludge would be a issue that would require action.
Great pics, thanks. So the whole instake, TB, inlet came out as one piece, right? Now that you sealed up the top end its time for the rear main seal to let loose, right? I hope you do an article on that.
The last time that I changed my spark plugs I took the whole intake off. I put it back with the original gasket. This time I think that I will put a new gasket in. I'm buying all of the parts incrementally so that I can get more discounts from AutoZone.
You don't want to mess with that rear main seal. If you think that the top of the motor is remotely complicated the bottom and removing the motor is a lot worse.
It is best to NOT use RTV on the rubber gasket.....it will be able to "float" or adjust as things expand and contract with the temperature cycles.
As someone mentioned.....maybe some RTV at the corners and on the "humps" at the ends.
I did not use ANY RTV but the factory had put RTV at the corners and the humps at the ends.
The ones I changed were factory original.
I have not noted any leakage on mine.....and I changed them in early spring.
Complete intake.....I did NOT separate the throttle body from the upper intake.
I only needed to move the complete assembly a little bit to get access to the rear valve cover.
It was enough work to disconnect the coolant lines to the throttle body and all the vaccum lines.....and bend over to get at the rear support bolts.
Can somebody pls advise me as to how to get the wiper arms off the spindles? I have taken out the nuts on top of the spindles but the wiper arms don't budge. I am afraid that wresteling with them in the wrong way may break them. Your advise as always is appreciated.
Gently wiggling and tugging did mine. At some point they both just popped off.
When you reassemble, consider putting a tad of never seize on the area that's bound. And take note of their exact position, maybe put some tape on the windshield to note how far out they should each travel so when you reassemble everything is as is was.
What should it cost to have the rear valve cover replaced at a shop?