Valve Adjustment on 3RZFE

Hello all. Its that time to check my valve clearance and have some concerns to ask. First off truck has 140k on it and the last time i had the valves checked was at the dealer at 100k. They said that the valve clearance was in spec but getting close to needing adjustment. So a couple weeks ago i did a compression check and valve lash checked every valve. The compression readings were pretty impressive.

Cyl 1 - 160psi
Cyl 2 - 165psi
Cyl 3 - 155psi
Cyl 4 - 165psi

Then i popped the valve cover off and checked each valve. All total i need to adjust 9 of the 16 valves to either get them away from the limit or to get them back into spec. It was 6 Exhaust valves and 3 Intake valves. Out of the 9 a couple were maybe 0.001 out of spec or getting close to being out of spec. My only concern are the two exhaust valves on cylinder number 3 which were reading 0.008 and 0.009. The factory says Intake limits are to be between 0.006 - 0.010 and Exhaust 0.010 - 0.014. Iv already got my measurements and have already ordered the new shims which will be in next Tuesday. My only concern is the two exhaust valves on cylinder 3... I know that whatever damage that has happened to the tight valves is already done and no sense in loosing sleep over it but is it possible that the two valves have already been burned? Or is that something that takes a longer amount of time to do? Is it when you have no valve lash that you now have a problem? I mean how critical are these clearances if there off by 0.002 for a couple thousand miles? And finally is it pretty obvious when a valve has been fried? My truck currently has no miss at idle or while driving and runs very strong. But beings two valves are about 0.002 past the limit concerns me. Iv heard of people never checking or adjusting there valves and they run them past 200k with no issues.

Thanks in advance for the responses.

 

My 3rz has 240k on it and never had a valve adjustment. Would make me think that its not going to hurt you for a few thousand miles. But maybe I need to get on that...

 

I'd expect much lower compression if a valve had burned, my guess is you're OK.

 

There should be specs for the face width of the valves, if you wanted to be 100% sure, you could take the head off and check the valves but to my knowledge most people don't even touch the valves on these trucks, running them to 500,000+ miles.

 

I recently reset valve lash on my 2000 3rz with 290k on it. I had 2 exhaust valves that were .008" clearance. I set all exhaust valves to .012-.014" and didn't notice any difference in anything. I suspect that in your case, any issue your having isn't due to the .008" clearance you have. I would correct it though. Here's the thread I started, I found it pretty easy to pull the exhaust cam to do this. I didn't mess with any of the intake valves since mine were all within spec and the intake valves don't get as hot as the exhaust valves. https://www.tacomaworld.com/threads/valve-lash-results-290k-miles.495565/

 

The valves have to be much further out of spec for them to be damaged. Mine were almost exactly like yours with cyl 3 at .008 and .009 at 175k miles. If you already ordered shims, I'm assuming you pulled your current ones so you knew which ones you need?

 

It would be obvious if a valve were burnt. The "burnt" means a small part of the valve is worn away and it will quickly get bigger and cause a misfire. It can't be burnt just a little for long. Search for pictures on burnt valves.

 

Yup bought the tools I needed to pop the old shims out and measure. Sucks because this is my only vehicle and I had to do this project in weekend steps. One weekend, measure clearance and put back together. Then take apart again, pull old shims, measure and put back together. Now waiting on correct shims and take apart again. I feel like I'm going to where the nuts and bolts off everything lol

 

Nice! Pretty clean for an engine that has close to 300k. I didn't remove the camshafts at all. Iv read that some do, but after reading someone's horror story of dicking the timing up, I was like yea, not going that route. So I watched a video of a guy using a Honda bike tool to compress the valve to insert the hold down tool for the bucket. So I went to Amazon and ordered both the cam pliers with the bucket hold down tool. Then found something very similar to the Honda tool in the video (part# 57-8019). And it worked like a charm. The last intake and exhaust valve on cylinder #4 took some fanagaling and body contorsion but had them out in 10 minutes each.

 

Well sounds like you'll do it in record time once you swap them out!

 

Awesome job. I watched that same video and it was very helpful. I feel like I cheated a bit not having used any special tools to remove the shim. I did buy the plier tool, but never used it. So did you find the Honda tool or the pliers easier to use?

 

My first car was a Fiat 124 with valve shims. I saw the tool for holding the tappet down to take out the shim recently.

 

Honestly the Honda tool allowed me to free up both my hands to position the hold down tool. So yes the Honda tool was easier to use. I did use the pliers for one valve and they worked very well. However you had to keep constant pressure on the pliers and rely on your other hand to correctly position the hold down. It would have been nice if there was a locking mechanism on the pliers so you could set them and then let them go. But it took very little effort to squeeze the pliers which was nice. The only thing with the Honda tool was it took some pushing to force it between the valve and cam, but once inserted, I could let it inserted while I positioned the hold down tool. Then could pull the Honda tool out with ease. I will say this tho... It would have been impossible to use the pliers on the last intake and exhaust valve on cylinder #4. You don't have enough hands to position everything. You would have had to have an extra set of hands working the pliers and another set of hands positioning the hold down tool and flashlight.

 

We really need to make a travelling shim kit from junk engines......lots of them interchange....Camry, Corolla, MR......etc. Shims, for the most part, do NOT wear out.

 

200k never adjusted mine lol

 

You obviously can read but don't fully understand the information. Valve clearances ensure the valves fully seat when the springs pull them closed. The extra clearance ensures that when hot that the valves fully close when parts expand. This also allows longer intervals between adjustments as the valve to seat wear in or wear away ensuring there is adequate clearance so the valve continues to seat fully.

Being close to the tight end of the spec or slightly tighter is not a concern or an imminent catastrophe. There is still enough clearance to allow the valve to close fully. When I built my race motors I always shimmed to the extreme end of tight clearance (still within spec) to give a microscopic gain in lift and duration.

When time allows do your re-shimming but don't get apprehensive in the meantime. You are going to be ok.

 

Had similar situation with my 2.4 and will probably check the clearances again after 30k instead of the 60k recommended (by some) interval.

 

Valve Adjustment complete.

 

Good deal man. Anything worthwhile to share?

 

Pretty straight forward with the right tools. Will say this tho. If you use the wedge tool #57-8019 make sure its fully seated and secure. I didn't have it fully seated and as I was placing the hold down tool the valve spit the tool out and it smacked me right in the forehead sharp side first lol. What did I learn.... once wedge tool is inserted, wait a couple seconds before getting in the line of fire. Other then that was very easy to do.