Valve Lash

[jfenwick]

Does the 1984 Toyota Van with the 3Y-E motor have valve lash?
I don't see anything in the engine mechanical part of the manual about changing the valve lash on the rocker arm assembly.
I may go into the valve cover so I want to know before I do that.

I've been trying to figure out if I should get rid of this van. It's been making blue smoke and burns oil, too much HC to pass smog.
I finally got around to learn how to do a compression test and it came out 170, 170, 160, 170.
Well, that 160 might have been a 150 the first time. I was having a hard time reading it since I've never done this.
I messed up the wet compression test unfortunately, probably put too much oil in there...

I'm thinking if I replace the valve seals it might fix the problem enough to get the HC under control.

I'm hoping I can get away without replacing all the gaskets. But just in case...

I have looked at many threads about rebuilding the head, and one thing that many people said is to make sure you use a Toyota gasket kit. Most of the links people posted have expired. I think this is the correct one for anyone looking:
https://www.toyotapartsdeal.com/oem/toyota~gasket~kit~engine~overhole~04111-73010.html

What about the valve cover gasket? Does that specifically need to be Toyota too? I might just try replacing the seals and the top gasket, if I can replace those without taking the head off.

Does all of this sound crazy? Can I get away with just replacing the seals and the one gasket?

[Diy2k]

Doesn’t sound crazy. The seals alone should make a big enough difference. Just make sure the valves are seating properly and the seals are new.

[Burntboot]

The valve train employs hydraulic lifters, so no lash to adjust.

The causes of your blue smoke could be many and valve seals might just get the pass
I would be tempted to start with a crankcase flush, that may also be enough to get the pass.
-If it isnt, the inside of the motor will be a lot cleaner when you do have to tear into it.

Replacing valve seals is possible with the head installed, but there are certain things one needs to do to be successful.
Most importantly is doing something to stop the valve from dropping into the cylinder after you remove the locks and spring.
(dropping a valve means pulling the head)
I prefer the rope method over compressed air, but YMMV

As to gaskets, any should work but OEM will almost always have a better "fit" and the valve cover gasket should be a rubber, not cork.

[jfenwick]

Burntboot, thank you for clearing that up!

I keep hearing mixed feelings out there about using solvents in the crankcase and the intake. I've heard using solvents in the crankcase can sometimes knock stuff loose and it can get stuck in the pump. I'm leaning toward doing it anyway and trying Seaform for both of those, and in the fuel tank. Maybe you're right and I could at least get the pass faster.

I was watching videos about working on this part of the engine this weekend, these are my two favorites related to changing the valve seals:

https://www.youtube.com/watch?v=_uO5YayiLrA

https://www.youtube.com/watch?v=bohwemehdIk

[Burntboot]

I've done it with compressed air, it only becomes a problem if the air pressure bleeds of or someone else uses the air supply or that 150pis starts pushing the piston back down the hole, as I have had ALL of those experiences I moved to the rope method. It takes a little longer but avoids all of the pitfalls of the other method. I start with the piston half way up, jam in as much SOFT rope as I can then turn the engine up towards TDC, once it wont go any further I know I am good.
The rope wont leak out and using a SOFT rope wont damage anything and the rope wont try to push the piston back down, all plusses in my mind.

The magnet and hammer method is interesting and I confess I didn't watch to the end to see how he gets the locks reinstalled.
But I wouldn't use that method, I prefer a proper tool, as it means no misblows with the hammer (and no bent valve stems) and easy lock instal.

The only other advice is, don't look to set any speed records.
You know the old saying: first you get good, then you get fast, especially true for those that aren't pulling wrenches everyday.
It is so easy to overlook something simple when trying to "get'er done".
Those mistakes are often expensive as well as time consuming.

I've heard the same horror stories about chemicals ruining a motor.
To be fair, there's some truth in it but its mostly an urban myth.
From the point of the repair shop, there's little profit in promoting chemicals, many would say it hurts their business.
And if you were contemplating using Varsol or diesel fuel then yes, you will likely destroy the motor.
Using a commercially available product, designed for the purpose, (with added lubricants) should not cause any grief, as long as you follow the instructions.
I have done hundreds of crankcase flushes and the worst outcome I have ever seen was "no change noticed".