Do you "Need" a valve adjustment? What are the benefits of adjusting the valves? Is it neccessarily a scheduled maintenance item? I know engines somewhat but I'm a bit fuzzy on the details and I don't do my own work. That's why I'm asking. I was actually told by someone I know who works at a dealership that you don't really need one on this engine. However if you can sell me and give me something to work with. I just want to stay on top of maintenance, that's all.

 

you should have it done, they lose adjustment over time, wear and tear.... its a pita on the v6s though

 

Has anybody noticed there 3.0 running any better after a valve lash adjustment. The valvetrain noise in my 3.0 is driving me nuts. Sounds like it gonna fly apart but seems to run great. I took it to some shops and they say they have heard WAY worse than mine and I could do without it. I have put 60K miles on the truck and never had one done.

I drove my buddys T100 the other day and the engine seems so smooth and quiet compared to my 4Runner. Both have 3.0's but he has had his lash adjusted when he did the timing belt.

 

Dont 'need' the valves adjusted?

BULLLLLLLSH**!!! LOL

The scheduled maintainance reshimming is what 80,000miles? You really dont need to do it THAT often, however every 150,000 I would at minimum. Why?

Well lets first look at how our exhaust manifolds are setup. If you look at it you will immediately notice that the crossover pipe dumps straight into the rear portion of the drivers side exhaust manifold AND is right there with exhaust valve #6. It's a relatively safe bet that exhaust valve #6 is getting a lot hotter (or has the potential) than the rest. What keeps it cool (and all exhaust valves cool) is their contact on the head. The head's aluminum is going to be around 195-200* vs the exhaust gass's 500*F - 1200*F So besides making a good seal, solid contact is needed to keep the valve cool too.

Over time even the hardest alloys are going to fatigue and strech as most are malliable...Exhaust #6 has a tendancy to stretch more than the rest (more heat = more malliable = streching) And if you are familiar with how these OHC engines are setup, each and every time that valve slams shut it's valve stem is being stretched slightly... This reduces the valve lash btwn the bucket's shim and the cam lobe.

iirc proper exhaust shim clearance is 0.011" - 0.008" On mine when I did my own reshim I was down to 0.002"!! What does it mean when your shim clearance is too low? It means that your valve is spending much less time contacting the head and cooling down than it should! This in upon itself could lead to a burnt valve, however usually the burnt valve doesnt occur until valve shim drops to zero. Then the valve starts to stop contacting the head and you loose compression....and you have burnt valve.

Follow the TFSM to the letter while doing these adjustments...You will need a feeler gauge and a dial micrometer for measuring tools.

First determine your valve lash following the TFSM. If out of spec pull those shims!

I did my own valve reshim job about 8 months ago and injector cleaning and porting the upper manifold... Its not an easy job, but not too hard either. Just REALLY time consuming! I needed to buy a VW shim puller, a magnetic wand, 45* angle LONG needle nose pliers, a nut on a string, a big flathead screw driver and a long handled allen key set.

First I made sure the VW shim pullers could access the shim recessions on the bucket with the cam shaft inplace. (This took some creativity and odd angles at times btw but it worked on all shims.) I used a small allen lever the valve bucket/shim down from the camshaft, jammed the flat head btwn the valve and cam, grabbed the next size up allen key, levered down the bucket some more, jammed the flathead in farther and got the last and largest allen key in there to hold hte bucket/shim down.

Next I used the needlenose pliers to position a nut(on a LONG string) on top of the lip of the bucket but not over the shim. (Doing that holds the shim/bucket a good 1/2" away from the cam.) I then used the VW shim pullers to pop the shim out of the bucket. (doing this takes some MUSCLE and FINESSE - you have to grip the shim HARD, yet carefully lift straight up.) Usually the cam would knock the shim out of the shim pullers and straight back down, but now your magnetic wand will easily pull the shim out without much ado.

Place the shim in a labelled ziplock bag - also writed down everything you do. Being meticulous is KEY!

Take care to NOT scratch the camshaft lobes. Make sure the string attached to the nut is STRONG and LONG and inspect it regularly. You do NOT want that little bastard falling into your oil return hole on each side of each head without that string. And when it does fall down there (and it will) the string will allow you to fish it out with no problems. Also when the nut goes flying off at 1000mph when it periodically pops out, the string will tame it down asap and allow you to find it very easily.

Reverse the process for shim reinstallation. Also there will be a few shims that youll have to order from your local toyota dealer.... They take 3 days usually to get there... And many times youll find that you ordered the wrong shim. Just be patient, anal, and meticulous.


My valve train got much much better sounding after I did it (not the train wreck sound like before.) AND my EX #6 wont burn up on me!

 

Buy some feeler gauges, pull your driver's side valve cover, position cam so that EX #6's cam lobe is facing completely away from the shim/bucket and measure your lash. Start at 0.005". Im willing to bet you'll have to go smaller than that to get the feeler btwn the camshaft and the shim. If its out of spec, reshim or you face a burnt valve.

 

I took a buttload of pics, I guess I should do a write up huh?

 

Yes, a write up would be KEY. I'm going to tear my junk down to do a timing belt and valve cover gaskets, so I'd like to do a valve adjustment while i'm in there.

 

I know this post is old but Bumpin' Yota, did you ever do that write up? I am going to be replacing my valve cover gaskets as well and wanted to check my valve clearances as well.