wrenchmonster

A valve burns for one basic reason (yes I know there are more, but I'm speaking generally).

The adjustment is too tight. The valve will be quiet if too tight. If the valve doesn't have enough TIME to transfer heat from the valve to the seat, then the valve will become super hot and burn, distort, whatever you wish to call it and eventually will not seal properly. Time is the key here. The valve has to be on it's seat long enough to transfer heat.

-Wrench

Mr pogo

I stand by what I said.
On OHCs the most wear is at the valve seat, normally very little wear at the lobe and shim/bucket/follower (depending on brand of engine). So lash decreases.
OHV with mechanical adjustment usually wear the most at valve stem and rocker arm tip so lash increases.

MTL_4runner

If you are keen to do the job there is plenty of info on YT about doing it:

For a 3.0L :
https://www.yotatech.com/forums/show...t=valve+adjust
https://www.yotatech.com/forums/show...t=valve+adjust
https://www.yotatech.com/forums/show...ght=valve+shim
https://www.yotatech.com/forums/show...ght=valve+shim (with clearances)

Here is for 3.4L (same procedure):
https://www.yotatech.com/forums/show...t=valve+adjust (this was when I first asked about it)
https://www.yotatech.com/forums/show...ighlight=shims (shimming procedure)

This was from Gadget:

"The valve train on the 5Vz engine is not hydraulic. It uses solid lifters that are not self-adjusting.

If the valves need to be adjusted, then they need to be adjusted. For anyone to tell you over the phone that your valves do not need to be adjusted doing you a real disservice and that is completely irresponsible and reckless on their part.

I think the maintenance book recommends the valves be checked every 15 or 30,000 miles. The quick check is to listen for ticking and check for a rough idle. The proper way is to pull the cam covers and physically check the lash with a feeler gauge. It is easy to check with a feeler gauge, and yes they are a pain to adjust.

If the lash is greater then spec it will tick and there will be accelerated wear on the cam lobes and the rest of the valve train. This however is better then the lash being to small or non-existent. If there is no lash that means the valves are not closing all the way and can leak combustion gasses between the valve and seat. This can over heat the valve and destroy it. Ever hear of "burnt valves"?

Remember, to much lash is better then not enough. You can hear too much, you can't hear if you do not have enough. A quick test for the more serious of the two is a compression check. You can do a standard compression check and if any cylinder is to low, then do a follow up cylinder leak down test. If it shows air escaping through the valves you had better adjust them fast before you need an overhaul.

Still the best way to know for sure is to physically check the lash with a feeler gauge. If you find that they are out of spec and need adjusting, the easy way is to do the adjustment in conjunction with a timing belt change. With the timing belt off you can easily remove the cams over the valves that need adjustment and you will not need the special adjusting tools that don't work well at all.

The procedure is to check the lash and record the lash that is out of spec. Then remove the existing shim and mic it. Then you look up the lash and the existing shim size in the chart in the FSM and it will tell you what shim to reinstall.

Shims are available from Partznet.com for about $8 a shim. The last time I adjusted mine I needed two out of 24. It runs fantastic and there is no ticking in my engine.

So, lets review. Whoever told you over the phone that you do not need to adjust your valves is a complete ass since his did not check your truck. Chances are you do not need to make any adjustments, but the only way to know for sure is to physically check the lash. If you are concerned, pull the cam covers and check the lash and then you don't have to worry anymore.

That guy that told you over the phone that you do not need to adjust the valves, is he going to pay for your engine overhaul if he is wrong or are you going to get stuck with that?

Gadget"

Happy reading!

whays

The special plier type tool is basically useless. I had much better luck using a long craftsman allen key to wedge under the cam and push the valve down. Then I stuck the wedge tool between the sides of the lifter and the cam to hold it open. You have to leave enough room to pull out the shims. The smaller side of the wedge tool does a nice job if placed next to the cam bearing side of the lobes. This gives plenty of room to pry out the shims.

If any of your valves are too tight then you can probably carefully grind down the shim on the side of a bench grinder. I rotated the shim and held it gently to the side of a grinding wheel until it got hot. Then I sanded it with some 150 grit. (The bottom of the shim, not the side that the cam lobes touches.) Measure the shim after each cycle on the grinder to make sure you don't grind too much.

As far as I'm concerned you need the following stuff to complete the job.
1. Factory service manual. Download it.
2. Micrometer to measure shims.
3. SST Wedge tool. Any tool truck can get it for you.
4. Assortment of long allen wrenches. The plier gimmicks suck.
5. New valve cover gaskets. Plus a little RTV.
6. New manifold gasket.
7. Probably a new throttle body gasket.
8. Might as well get a new PCV valve.

I found a couple of exhaust valves that were tight. And a couple of intake valves that were a little loose. Nothing more than a couple of thousanths.

I have 162,000 miles on my 3.0

I guess I have a burnt valve because my exhaust pipe will suck in a dollar bill. I also have a spark plug may come back out, but will never go back in again.

gbean

So I took the head off the left side of my 3VZE to see why I had 0 PSI in cyl #6 on a compression check (was running rough at idle and failed the CA 15 MPH emissions test). I found nothing but an exhuast valve that wasn't closing all the way. I could slide a strip of 24# paper between the seat and the valve. Then I took the shim off the lifter cap and then I found this thread.

What should I do now? I asume I just go buy a thinner shim, but I am thinking the valve may be bad. Should I just replace that too? If I do replace it, should I just get OEM size and throw it in?

Please help, this is the most in depth mechanical work I have ever done on a vehicle without help. I also am wondering if it is possible to find single head gaskets, and not the whole kit.

This has been one big PITA.

CoedNaked

I have heard the exact same thing, from a dealership. I was told not to bother, it's not worth the money. I was told this from one of the best Toyota technicians in all of Canada that it's not worth it.

Raynyc

can you email me that TFSM? dontaskever@hotmail.com thanks

mwsmith887@gmail.com

I have a 92 4Runner 3.0 I stripped the bolts out on the cam cap on the very back of cam how can I fix this ?