Toyota Tacoma V-6 1GR-FE valve clearance (lash) check and results

I thought I would post this since I was looking for info on checking valve clearance on the Toyota 1GR-FE V6 motor and didn’t find much out there and lots of wrong info as well. I was checking this on my 2006 Tacoma X-Runner with 149K miles.

I’m typing this from memory so I may have left out a few things or described something poorly but it hopefully points in the right direction. This took me about 5 hours to get done. I’m pretty methodical and take my time so it could go faster I’m sure. It’ll be faster next time I do it for sure.

The 1GR-FE motor in this 2006 truck DOES NOT have hydraulic lifters that self-adjust for valve lash. It uses a “shim under bucket” arrangement like most high performance 4-valve per cylinder DOHC motors. I don’t know when you should first be checking them but probably before the 149K this truck has. I’ve had it since about 80K and it’s the first I’m doing it.

I’ve checked valve clearance (also called lash) on a number of car motors in the same way but by far the most frequently on the many 4-stroke motocross bikes I’ve owned over the years. The basic procedure is pretty similar for most motors that use this type of valve actuation.

The basic idea is: Pull off everything blocking access to the valve cover(s). Pull the valve covers. Rotate the crank to Top Dead Center (TDC) on a single cylinder engine (dirtbike) or TDC and then several more angular stops along the way to check the valves on a multi-cylinder engine (like this XR).

With the crank rotated correctly the camshaft will have its lifting lobe pointing away from the valve and shim and there will be clearance between the two. Or at least there should be. This is the valve clearance or lash. This is checked with feeler gauges that correspond to the gap being measured.

On the 1GR-FE I followed along thru the beginning of this video linked here:

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

These gentlemen are getting the motor ready for a head gasket change. It’s good for seeing most of the basic disassembly steps necessary up until the valve covers are removed. I’ve noted below where I did a few things differently or just things to remember.

I disconnected the positive battery terminal since I didn’t want any chance of the motor turning over while I was wrenching away with the valve covers off.

I took a spray bottle and a scrub brush and cleaned the valve covers, cable loom, hoses, and everything near the valve covers that might have dust or dirt on it that could fall into the open heads after pulling off the valve covers. 5 minutes here might save contaminating your valve train that you hope will go another 100K miles. Another step that makes lots of sense when working on dirt bikes.

I didn’t drain the coolant. When checking the valves the only “coolant” lines you’ll need to pull are going into the throttle body housing. These are high enough above the radiator that there isn’t coolant in the lines. Just loosen the hose clamps on the housing side and pull the two hoses. Even if they’d had coolant in them I would have just plugged them.

Most of the places where the wire loom is attached to the valve covers I just cut the OEM ziptie clamps and then re-zip tied them with separate zip ties after I was done. Some of these are difficult to get to and remove and I know I’ll be going back in here again in the future.

I labeled some of the hoses and cable ends with tape and a marker where I thought I might be confused getting them back in the right place. I also took some pictures with my phone of the cable/hose layout before pulling stuff off just in case.

Once you have all the hoses and cables disconnected from the intake manifold it is released by undoing the 4 socket head cap screws and 2 nuts down the middle and the three separate brackets attaching it to the cylinder head. From there mine came up pretty easy without using a mallet or any prying. Remember never pry on a gasket or sealing surface.

Once the intake manifold was off I stuck some shop rags in the intake ports so nothing accidently dropped in there.

I would suggest pulling all 6 spark plugs. This is an easy time to change them if they need it and it makes turning the motor over much easier.

On the RH cylinder head you’ll see a handful of hoses/fuel lines that are right beside the valve cover. I pulled these back and away from the head as much as possible (don’t bend/stretch anything) and held them back with some Velcro ties.

As you’ll see in the linked video there is one electrical cable that crosses over the RH cylinder head that goes down past the alternator that doesn’t have a connector (why didn’t they add a connector here???). I cut some binding tape that fastened the cable to another loom down low (careful not to cut/clip the cable) and that gave enough slack to clear the valve cover when it came time to pull it off.

One of the main cable looms terminates in the fuse box on the RH side. Pop the fuse box lid and there are a couple of tabs that release a snap in piece that holds this big cable. Detach the two connectors and it comes out easy.

I also pulled the two main cable looms together centered over the intake manifold area and Velcro tied them in place. Now there is pretty good room to get the two valve covers off. There are I think 6 screws and 2 nuts around the outside of each cover and 3 screws down the center. Neither cover pulled up easily for me and I ended up using the short end of a pry bar to pull up (like a slide hammer) on the “pry tabs” and then they pulled off okay. Careful not to catch the gasket on anything as you pull off the cover.

Okay let’s check some clearances. First we need to rotate the crank to TDC. Check out the linked document here that shows which valves to check at what crank rotation. If the cam “zero” reference marks aren’t lined up when the crank pulley is at zero then you need to rotate another full revolution to zero and re-check.

https://www.purefjcruiser.com/docs/...ngine Mechanical/Valve Clearance/00600310.pdf

The basic sequence is: Rotate to TDC and check 8 valves (4 intake 4 exhaust), then rotate 240 degrees clockwise (from TDC) and check 8 more valves, then rotate 240 degrees clockwise again (now 480 degrees from TDC) and check the last 8 valves. The linked PDF will show you which valves to check at each rotation. But it will also be obvious since it will be the ones where the cam lobe is pointing up and away from the valve.

At first I was trying to figure out how to attach my degree wheel to the crank bolt, but then I realized all I needed was an approximate 240 degree position. We aren’t timing a cam here, we’re just getting the cam rotated away from the valve. So I took my degree wheel, held it centered on the crank nut, aligned 0deg/TDC with the zero notch on the crank pulley and then put paint marks on the crank pulley at 120 degrees and 240 degrees. You’ll rotate the 1st time to the 240 degree mark and the 2nd time to the 120 degree mark (480 degrees total). Any basic protractor/angleometer should work fine for marking these points.

I would suggest writing down the measurements you get for each valve so you can refer back to them later or especially if you have any that are out of tolerance. You’ll need the actual feeler gauge reading if you have to make adjustments and you definitely don’t want to be confused about which reading was taken for which valve after you have the cams out and have ordered shims.

You will need the clearance to calculate the required new shim and then match that shim back to the valve that needed to be adjusted.

That is a whole other process at that point. Just make sure you know which measurement was taken for which valve. Drawing yourself a little picture or matrix can help get the numbers in the right place.

This is probably pretty obvious but when you’re checking the clearances; whatever feeler you choose to start with you should always end up with a feeler that goes into the gap and the next larger step feeler that doesn’t. The gap is the size of the last feeler that you could fit into the gap. But don’t stop checking until you know which one went in and which one didn’t. I’ll sometimes make notes to myself “tight” or “loose” next to the number that went in to know which side that measurement was on.

The spec for the intake valve clearance is: 0.006-0.010” and I got measurements of 0.008-0.009 on all valves.

The spec for the exhaust valve clearance is 0.011-0.015”. I got measurements between 0.014-15 on all but one that was 0.013.

Like most motors with a “shim over bucket” design; as the valves gradually wear into the valve seats the valve clearance between the cam and shim should get TIGHTER. That means if your valve clearances are towards the low/tight side then you are closer to needing to make an adjustment. If they are in the middle or towards the high/loose side then you probably won’t need an adjustment soon.

It’s amazing to me that this motor at 149K miles has all the valves in the middle or at the high end of the spec, meaning they should have lots more miles before needing to be adjusted. If this is typical of these motors I can see why I’ve seen people say they can go for 250K miles before a valve clearance adjustment. If only I could say that for my dirt bikes . . . I know different usage and state of tune!

Re-installation is the reverse of disassembly. I found spark plug install details and torque values on this PDF here:

https://www.tacomaworld.com/threads/how-to-spark-plug-change-1-gr-fe.30479/

https://www.tacomaworld.com/threads/the-torque-spec-guide.318116/








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Try this on. My 295k mile 4.0L V6 only had one valve out of spec when I did my head gaskets. I not surprised to see the values you measured with the miles you had.

 

That is pretty amazing! What a great motor. Were you losing compression or were there other signs you needed head gaskets? I want to check both compression and leak down on the motor. That's next up.

 

My truck ran fine before replacing the head gaskets. I have owned this truck since 200k miles and never had to add coolant so when the overflow level started to drop slowly it was noticeable. I was only able to confirm it was the head gasket by pressurizing the cooling system and then borescoping the cylinders one at a time. Only then could I see a single drop of coolant come out from the head gasket and run down the cylinder wall. I never got around to doing a compression test at the time.

 

Nice! I need to add that to the list of ways to check for head gasket issues. Having just recently got a borescope I'm still realizing all the things you can check with them.