Valve Cover Gasket - RTV ? - Toyota Nation Forum : Toyota Car and Truck Forums

coffee-3000 · 11-05-2011, 09:36 PM

I'm planning on changing my rear valve cover gasket soon.
But where on the valve cover do you put the RTV sealant ?
This picture posted on the forum shows it being place on the left and right sides only.
Thanks again.

71Corolla · 11-05-2011, 09:50 PM

ooops wrong engine. Don't forget to remove the "half moon" plugs, clean them and re-seal them. You put the sealant on the cylinder head not the valve cover.

coffee-3000 · 11-05-2011, 10:11 PM

Thanks 71Corolla. I'll apply the RTV to the 6 spots shown in your diagram. I'll put the sealant on the cyclinder head rather than the valve cover as shown in the picture in my original post. (What was that guy thinking ?) I'll also remove the half moon things and seal all sides with the sealant.

coffee-3000 · 11-05-2011, 10:15 PM

One more stupid question. Does the rubber gasket make contact with the RTV Sealant once you place the valve cover on the cylinder head ?

71Corolla · 11-05-2011, 10:32 PM

Yes the rubber contacts the RTV. Which is fine because RTV is liquid rubber which vulcanizes in the presence of oxygen. They key to a good seal is to make sure everything is clean and oil free. If it is, RTV bonds readily to the aluminum and the gasket.

***JohnGD*** · 11-06-2011, 04:14 PM

Try to make sure the RTV from the semi-circular plugs don't fall into the cylinder head. A wire brush helps too. Stuff paper towels nearby while cleaning. Clean the RTV surfaces with alcohol otherwise it may not stick.

Permatex Ultra Black or Ultra Copper (high temp) work fine.

And check the cover nut torque after a few warmup cycles. They tend to loosen a bit.

coffee-3000 · 11-06-2011, 07:49 PM

Thanks JohnGD. But is it possible to check the cover nut torque after the warmup cycles since the rear valve cover is burried under the plenum ? Or is there enough clearance to check with the plenum on ? Also, do I remove the half moon plug from the cyclinder head and seal all sides ?
Thanks again for you comments.

***JohnGD*** · 11-06-2011, 09:13 PM

hehe was looking at the picture, my bad. I should read the fine print - V6 engine.

The 4-cyl likes to come loose because the cover gasket design is poor. But for the V6 you should add one (or two) washers to the bolts, or use new bolts. Because the wavy springs loose their tension and that's how V6s like to leak.

I think it's better to add washers than getting new bolts. And once torqued down the v6 covers should be fine. Just leave them for 30 minutes or so and then retorque again.

Check out message #5 here:
OEM VS Felpro Valve cover gasket

coffee-3000 · 11-07-2011, 06:27 AM

Thanks JohnGD. That post by ajkalian ( with pictures) is great. I'm definitely going to add an extra 8.5mm washer ( or maybe two) to each bolt.

One more question. The Haynes manual says to take off the plenum and throttle body as one unit. They say not to disconnect the throttle body from the plenum. But I've seen some posts on this forum saying to remove the 4 bolts that attach the throttle body to the plenum and remove the plenum by itself. Which do you perfer ? Which is easier for a novice ? Thanks again.

ajkalian · 11-07-2011, 07:47 AM

Quote:

Originally Posted by coffee-3000

Thanks JohnGD. That post by ajkalian ( with pictures) is great. I'm definitely going to add an extra 8.5mm washer ( or maybe two) to each bolt.

One more question. The Haynes manual says to take off the plenum and throttle body as one unit. They say not to disconnect the throttle body from the plenum. But I've seen some posts on this forum saying to remove the 4 bolts that attach the throttle body to the plenum and remove the plenum by itself. Which do you prefer ? Which is easier for a novice ? Thanks again.

I've always removed the throttle body from the plenum. Since you are going through all this effort you might as well clean the throttle body while it is disconnected. Remove the butterfly valve and scrub it clean with a brass wire brush. Now that you have the throttle body on the bench, remove the IAC and clean it. Be careful with the screws, they strip easily. Use small vice grips to break them loose, and replace them with bolts, or Allen bolts.

You will need new gaskets for the throttle body, as well as the IAC valve. You should also get new gaskets for the EGR valve. I'd take the EGR tube off completely. It's probably in need of a good cleaning as well.

With the plenum separated from the throttle body, you can remove the cover on the end of it, it's called that ACIS (Acoutic Control Induction System) Anyway, it will be full of crud. Clean it out as best you can. Hot tank it if you have access to one. You will need a gasket for that as well.

Here are some pics:

http://i125.photobucket.com/albums/p...SDC11507-4.jpg
http://i125.photobucket.com/albums/p...SDC11515-1.jpg

This might seems like a lot of extra work, but now that everything is apart, take the time to clean everything up.

Be sure to mark the Throttle Body gasket. It's easy to get on the wrong way and all your hard work will go for nothing, when you try to start up the motor. Tape the old one to the throttle body to be sure. Don't do what I did, and mark it with a Sharpie, and then clean the Throttle Body with lacquer thinner, and wipe off the marks.

Some other things. The wiring harness is held on to the back valve cover by two small long bolts. At least it is on the newer ones. Anyway, remove them. They are very small, and have a star head on the top. Maybe yours will be different. With them removed it will be much easier to get the valve cover back in place without smearing the RTV.

There is a wire that connects to the power steering pump and it is hard to see. It's part of the wiring harness, and it is on the passenger side. It keeps the wiring harness from coming loose and with a frustrating tug it will pull right out of the connector. Ask me how I know that. Before you ruin the wiring, unclip the connector from the power steering pump and the wiring harness will come loose much easier.

There is a hidden screw holding the wiring harness on the passenger side near where the valve cover meets the block. It's hard to see, but if you look you will find it. Might be different on yours though.

I know that the FSM says to put a little dab of RTV here, a little dab over here. Call me a knuckle dragger, but I put gasket sealer on everything. On the valve cover, the gasket, and the head. I want that damn thing to stick. I want to have to use a jack hammer to get it off. Permatex makes a nice gray sealer, that matches the aluminum motif of the engine.

Here's a thread on the IAC valve:
Anyone adjust the IAC before?

And if you want the epic thread on timing belt, water pump, throttle body, IAC and most everything on the top of the motor, check this one out: Need Advice

Good luck. Keep us posted.

.

coffee-3000 · 11-07-2011, 01:45 PM

Thanks AJ for your comments and pictures. I can't wait to try this. I'll order the EGR gasket, TB gasket, and valve cover washers from the dealer. It sounds like the valve cover work is the easiest part of the job.
Removing the TB, EGR valve, and plenum sounds tough.
But I think I'm up for it.

ajkalian · 11-07-2011, 02:19 PM

Quote:

Originally Posted by coffee-3000

Thanks AJ for your comments and pictures. I can't wait to try this. I'll order the EGR gasket, TB gasket, and valve cover washers from the dealer. It sounds like the valve cover work is the easiest part of the job.
Removing the TB, EGR valve, and plenum sounds tough.
But I think I'm up for it.

First time is the hardest, that's for sure. I don't know if you have had time to read through that epic thread by Pmesfun but when he did this to his car earlier in the year, he was 17 years old. I think he turned 18 sometime this year.

I about fell off the floor when I found that out. So take your time, and don't get frustrated. It can be done, and you can do it.

Edit: Here's another thread on changing the valve cover gaskets.
http://www.wjowsa.com/carstuff/toyot...lve-cover-job/

.

coffee-3000 · 11-07-2011, 04:09 PM

Do you think that it's possible to leave the EGR valve in the car but detached it from the plenum ? Removing the EGR valve looks like it will be very difficult. I'm wondering that if I remove the 3 nuts shown in this photo, will I be able to unhook the EGR from the plenum.

ajkalian · 11-07-2011, 07:49 PM

Quote:

Originally Posted by coffee-3000

Do you think that it's possible to leave the EGR valve in the car but detached it from the plenum ? Removing the EGR valve looks like it will be very difficult. I'm wondering that if I remove the 3 nuts shown in this photo, will I be able to unhook the EGR from the plenum.

Look on the back of the EGR valve. You should see a gold colored pipe connected to the rusty part of the EGR. How is that attached to the EGR valve? If it's a couple of nuts, then with the throttle body off you should be able to remove the nuts and the EGR valve should be easy to remove. Look at the bottom of the EGR tube. If it looks like the top, that is, it has a flange and two nuts, then it is a snap to remove. Unbolt the bottom nuts, and then the top two and it comes right out. Some EGR tubes (I can't remember the years) have a large nut on the bottom of the tube and a compression fitting. That's a bit harder to muscle off, but once the bottom one is off, the top nuts should come off and you can remove the EGR valve.

You can also just remove the nuts that hold the EGR to the throttle body, and bend the whole assembly out of the way. It's probably not the best way to do it,

but you can bend it enough to get it out of the way.

Bend it too much, and you risk kinking the tube, or split the flange at the bottom and then you will have to get a new tube. I can't remember if yours has the tube bolted to the EGR or not. Take a look, maybe post a pic.

It will be worth the effort now to get the EGR tube off completely because it might be clogged with crud. Some pics I've see show them almost completely blocked. It wouldn't hurt to scrub the EGR valve and clean it up as well.

Some members have reported that the nuts on the EGR valve are frozen to the studs, and the studs break off. Major PITA if that happens. You have to drill and tap, and get new studs.

Good luck.

***JohnGD*** · 11-07-2011, 09:49 PM

If the pipe is bolt on and with the nuts/studs removed would the intake plenum come off completely with the EGR valve still attached? Looks like it should.

OP should also use masking tape or other things (tin foil, clean shop towels etc) to cover up the intake ports when the plenum is off. Don't get dirt in there and try to clean off as much as you can before removing the plenum.

It would be a good time to measure valve clearances too. It's not too difficult to do. However, it's a good time to change out the valve stem seals if doing the timing belt and the intake plenum is off. But stem seals need special tools, and probably isn't something I'd recommend on a first attempt.