Remedy Leaking Valve Guide Seals

<3/29/2025 Updated at bottom of post>

I am starting a post to gather knowledge and share experience of replacing the Valve Stem Seals in my 1GR FE.
I have been aware of a leaking seal in my Cylinder #2 for a couple years now. I can see the affects on that sparkplug and compared the top of piston #2 with #1. #2 is clearly covered in carbon, #1 is clean. I also consume more oil than before this was assumed to be the issue. Upon discovery I conducted a compression test to verify where the oil was going. All cylinders were well within spec and balanced between each.

I will be including pics of the spark plugs and top of piston via snake camera.
Top spark, Cylinder #1, consistent with all but #2, shown below. Ignore the wetness on #2, it's WD-40. The bottom boot from the coil got stuck to the porcelain and had to wrestle it off before removal.

Piston #1


Piston #2 Icky


Internals from last time the valve cover was off. About 9k mi ago. Changed the driver side Valve cover gasket.
In my opinion this looks good in regard to sludge.



Looking for-
Others that have successfully completed this operation.
I borrowed a 20gal compressor, but only gets up to 85psi. I will experiment with this before trying the rope method.

Techniques for getting to the seals with minimal tear down. Can the front engine cover remain in place? Do all the chains need removal?
-Confirmed front engine cover can remain in place.

Tools for the Job?
On hand: A specialty plier to grab seal. May be useful for removal and instal of inserts.

On Order: A specifically modified removal tool from Monkey Wrench Racing.
https://www.monkeywrenchracing.com/product/mwr-toyotool-valve-spring-tool-2zz-1zz-2gr/



Sources for instructions?
Not the exact motor but process should be similar. https://www.lextreme.com/how-to-replace-toyota-and-lexus-valve-seals/

How to acquire a Factory Repair Manual?
@rheath08 provided the 1GRFE disassembly and reassembly section. Should be all that's needed.

Preferred valve seal Manufacturer and source/vendor?
I demanded on SuperTech. Which uses VITON high temp material on the exhaust side and a lower temp material on intake. Which is the same scenario as factory; to my surprise. LCengineering has VITON on both sides.

Other items to address while in there?
I have Solid Offroad Motor and Trans mounts on hand. May try to do the motor mounts while in there.
I'll put in a new set of intake manifold and valve cover gaskets. New Oil control valves and screens.
May replace the stock pulley with tensioner. I have replaced most pulley/bearings, including for the S/C. Because water crossings.

Benefits to upgrading the valve springs?
Probably not worthy unless I upgraded stock rods and wanted to rev higher.
Pass.

What to do before tear down? Should I Seafoam the head and/or cylinders?
I plan to clean out as much carbon as possible before tear down. I want those valves clean and smooth for the reinstall. I have had the valve covers off a couple times for Cam Gear swap and valve cover gasket replacement. Very clean minus some tarnish.
I started with a can of Seafoam in the gas tank.
Will do the Seafoam Top End Treatment in the coming days. I do have concern for how it will interact with the silicone gasket in the S/C intercooler. I have gone through a couple of those over the years. The adhesion fails and they get swallowed up. May order one to have on hand; they are $35. Anyone have a source of a roll of that stuff? Must be a cheaper source.
I am ~500 mi from an Oil Change. May add to crankcase soon with the intention of performing oil change sooner than normal. Should I change oil right before the tear down or after work is complete, but before startup?
Recommended to change after completion.
I did the Seafoam Trifecta. Post pics of the piston tops shown a significant amount of carbon removal. Will likely do another round of the top end cleaner after proving all work was as intended.


I have identified some specialty tools. Will add links.


The truck-
Currently at ~220k mi. Have had Supercharger installed for almost 100K mi. Many supporting mods to achieve 8.5 to 9.5 psi of boost; weather dependent. Opened up the intake and entire length of the exhaust. Currently maxing out my MAF as I have exceeded the bandwidth. Subaru replacement in hand. Was running the UCON from URD for the first few years, have been OTT tuned by @JustDSM since then.
I drive the truck aggressively, use it to do truck stuff, drive cross country all times of the year, including remote camping or getting to remote trailheads for backpacking and need to be as reliable as possible for safety concerns.

Experience-
I am not a mechanic. I work as an Electronics Technician.
I have done all the work to my truck, minus clutch replacement and Hydro Bearing upgrade to remove the faulty T.O.B.
This includes S/C install, fuel pump, smaller pulleys, Cam Gears, URD headers and Y-pipe, "fab'd" my own 3" cat-back, entire suspension, stereo, gauges, Dakota Speedo corrector, front and rear diffs, cut fenders and made fender liners for 35" tire fitment, brakes, yada-yada... Just to give an idea of where my skill level is and to show others what can be done.

Recently created build thread. In progress.
https://www.tacomaworld.com/threads/t2-2008-trd-off-road-ac-6spd-s-c.848947/#post-30338705


I will do my best to document with Pics what the process is.
*Please keep on-topic so this can be a valuable reference.
Thankyou for attending my TED Talk.

>>>>3/29/2025<<<<
Returning for some updates.

Truck has been put back together and running for a couple months now. No issues have arisen. There is still some oil consumption. Too soon to tell if it has reduced.
This was a pretty big job for me, mostly time wise. Nothing was too complicated.
I checked valve lash of all shims before removal. They were all perfectly in spec!
I will get some pics of the cylinders next time I have the S/C off.

I am very happy that a had the Monkey Wrench Toyo Tool. The first removal and reinstall of the Keepers went perfect on the first attempt. I did have a few that took a couple attempts. Highly recommend. The most challenging part of the job was removing the old Intake Seal. I had 3 pairs of Seal pliers that were all slightly different. One had a band to it that helped on the cylinders closest to the firewall. I filled some deeper grooves in another pair to get more bite on the seal.

To remove the stubborn seals, I would use a pick to open up the top of the seal and squirt a little oil on the stem. Then squeeze, twist and rock back and forth while pulling up. I assume it was the difference in material between the Intake and Exhaust seal. Since I am boosted, the Intake sees more heat than typical.
I used a small air compressor to fill the cylinder. I have adapters from my compression check kit that worked very well. Used the straight shaft on most. Then a flexible hose for cylinder 5 and 6, next to the firewall. I did not try the rope method. That would have added considerable time.
When I first inspected the secondary chains they seamed loose. Especially on bank 1, passenger. The tensioner was not rising to the top. I ordered both secondary tensioners. Later learned that was normal, the tensioners are hydraulic. Installed the new ones anyway. The Main tensioner was OK. The chain guides showed minimal wear.
I was able to fully remove the Main tensioner through the inspection window. That provided me with enough slack to pull the chain up and over the cams. Greatly aiding in setting the timing. I tried to keep constant upward tension on the chain. Using a set of bungee cords and bailing wire to get it to the right height.
I purchased an organizer for top end work. This provided space to lay out the cams, buckets, springs, shims and keepers in an orderly fashion.
I tended to work through the seals one at a time. Except for a few cases where I let a seal soak and moved on to the next.
Throughout the process I took lots of pics. These were very helpful when assembly commenced.
In one instance right after reinstalling the keepers, they popped out and shot up and away. I had rags in all the orifices of the engine. I was able to find both keepers and shim! One on the floor, another on the top of the frame.
After reassembly of the cams, I checked the valve lash again. One was too tight for the feeler gauge. I thought I either accidentally swapped buckets when doing more than one seal at a time. Or the keepers had loosened up within. All the other valves were to spec. I then had to remove the cam in question. I did find the keepers had unseated. This bushed the bucket up and out of spec. Remedied, reassembled and all was well.

Critical tools-
ToyoTool for the Keepers
Telescoping magnet for Bucket and Keeper removal.
An organizer tray.
Seal pliers. Recommend having one that is angled and a straight one.
Oil squirt can, keep it all lubed up through out.
Torque wrench, both in ft. lbs and in. lbs.

I'll put notes to the pics below in the coming days.

 

Some pics of the parts and process.

 

I have rebuilt my 06 1grfe engine, have done valve guide seal before that. Feel free to message me with any questions.
Seals: I have some factory seal laying around. Been about 3 years since the rebuild. If you want them you can have them. I used aviation seals. I got them from rockauto.

Tools: rope method should work. I have heard about that and talked to people who have done it. I have not done it myself. There is a tool out there to install the keepers. To make it easier. Installing them by hand is a PIA and tedious. I did it by hand for the rebuild and can install.
There is a in car valve spring remover kit. I'll look to add a link later.

Springs: for the benefit of better valve seating and sealing, might as well while you're in there. Don't want to do it a second time.

Change the oil after repair. That way you can flush out the assembly lube once you know the repairs are good and have no issues.

Oh! Get 2-4 extra valve keepers. Those tiny little bastards like to walk off. Or learn to fly.

The front of the engine can stay on, all of it. Well minus the small cover to access the lower tensioner.
You can remove the cams with gears still on them. Make sure you properly label the cams and their location they are all different. Nobody wants to bend a valve.

Repair manual: I have access to it. Let me know and I can down load it. I may have a copy on my computer.

Might as well get some performance camshafts to install while your doing all this work.
It's just money.
I just joking around. But now would be the time if that option is doable.

If I miss any of your questions hit me up. I'd be glad to help.

 

There are several options for different Valve Springs. Sounds like there is a balance between too soft and too stiff.

Cams would be nice, but I have to cut myself off at some point. Though, for the right price...
I'll get some keepers on order. Anyone know the P# off hand?

 

This kit is similar to what I used. This has more parts and tool to go with it.

$59 Orion Motor Tech Valve Spring Compressor, Universal Overhead Engine Valve Spring Remover and Installer OHV OHC Compressor Tool, Valve Stem Tool Valve Holder Tool Valve Keeper Remover and Installer

https://www.amazon.com/Orion-Motor-...5&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY

something like this for removing and installing the keepers

$33 36050 Valve Keeper Remover Installer Kit Valve Spring Compressor & Retainer Removal Tool fit for Toyota Four Cylinder & Chrysler New World Engines with Valve Stems from 4.5 to 7.5mm and 5/16" to 3/8"

https://www.amazon.com/36050-Instal...efix=valve+keeper+install+tool,aps,194&sr=8-5


Keeper part number 90913-03028 Lock, Valve Spring Retainer

 

I still have a couple of keepers. You can have them.

 

There was a dude would got in on the kelford GB that was wanting to sell.

Bad thing....he was located in Hawaii.
Good thing... I'll be there in a few days for over a week and I'm willing to help broker the deal if you need me too.

Might be priced right to convince you to do the cam upgrade.

Found it:
https://www.tacomaworld.com/threads/kelford-cams-gb-2.837206/page-2#post-30084159

 

The process has begun. I am taking care of several items while I'm in there.

Big thanks to @rheath08 for shipping out his spare keepers! Hopefully I don't need them.

Replacing knock sensor harness because of mice; my sworn enemy. That was a challenge. But I avoided having to take the heads off.
Cleaning out the OCV filter screens.
Maybe do the solid engine mounts while I have better access.
Upgraded Big 7 wire upgrade.

While checking timing and measuring valve lash before disassembly, I noticed the Chain #2 looses tension during parts of the stroke. But then tightens back up. I am only rotating clockwise when facing the engine. I swapped in the 3deg exhaust cam gears several years ago. Hard to say if that was noticed before.

The tensioners do not feel really smooth when I push on them. No 2 tensioner slides up from the bottom. Slack is seen on the top, which is not the side that receives the tension. Would the tension be constant when under load/running? The No 3 is top down. Hard to say if that chain gets loose during the rotation.
Not sure what is normal. Tempted to just replace both of them. The No 2 tensioner cost is 2.5X more!?


I do see some inconsistency with the timing marks. Maybe I'm looking too close. When the crank pulley indicates TOD, mark aligned with the "0", the cam pulley marks are not quite aligned.









And then if I move past the crank "0", and get all the cams and gears aligned-
Is this too far off relative to the cam alignments pictured below? The timing cover and main chain have never been touched AFAIK.




Hard to capture this angle







I see a clear difference in the tarnishing of the VVTI sprockets. The L.H./driver side looks burnt. Could it be related to the number 2 piston with the leaking valve seal?


Another discovery was on the coolant thermostat extension that comes with the Magnusson S/C. Appears a belt is rubbing right through the aluminum!
Haven't looked into it much yet. Also replacing the thermostat and housing and going back to stock w/ a 180. I have the URD spacer and 170 degree T-Stat. It is leaking again. Not sure if it really improves performance outside of a very narrow window. And I think the truck would do better to warm up more in the winter. I get a lot of condensation in the catch can.



Will be updating the main posts in the coming days.

 

That looks like timing chain stretch.
Since your half there or more, might want to put new timing chains and tensioners. Go factory for the tensioners.

 

Nooooo!
The paint on the No 1 links still look good. Bright orange, so it didn’t overheat. Was hoping it was OK. Can I confirm without disassembly? Can that tensioner position be an indicator?

Is the color difference between the VVTI gears a concern? I have no check engine lights.

 

I found several threads showing the same issue with the No 1, main timing chain. A few replaced the chain and associated parts and resolved there issue. I want to rule out any other possibilities before moving forward. I will inspect the No 1 chain tensioner tonight and see how far extended it is. If it happens to be seized in place, could replacing it tighten the chain up to where it needs to be? Probably a stretch, te he.

 

I would not worry about the discoloration. That can be contributed to the way the crankcase breaths. The upper tensioners don't have much tension on the chains without oil pressure, so some of that may be normal. I don't remember what mine were like when I was inter last. To check the chain, it will need to be out of the truck. There is a spec X number of chain links should measure between X-X length. With no check engine lights on there is not enough stretch for the ECU to deem a problem. It is your call to reuse the lower chain.
If the lower tensioner is seized, replacing it will only take up slack and the timing marks will still be off what the are. If you don't have timing chain rattle then I would doubt it is seized. Timing chains will stretch with use, they don't have to be overheated.

 

Picture of the main chain No 1 tensioner-
Appears that the tensioner has barely moved.

I have seen posts, including Gadget from URD that timing has been set wrong straight from the Factory. Not 100% confirmed.
I have no other evidence of timing issue beyond a few degrees being pulled at high RPM and >1-3lbs of Boost. No codes or cold start rattles. Does not occur if I rev up to 5k while still in vacuum.
Justin confirmed it was being pulled at high RPM/load conditions. It is a faint rattle. Sounds like it is coming from bank 2. But that is from the cab while driving so hard to say.

My assumption was- Since I began to burn oil, can see cylinder #2 spark plug has deposits indicating oil being burnt, the top of piston #2 has way more carbon when comparing to #1, which spark plug matches all but #2, some smoke at startup, all indicates a leaking valve stem seal. The carbon build up is causing hot spots to ignite and has increased compression on that 1 cylinder. Hence detonation.
I had found a mouse nest in the engine valley and later confirmed the knock sensor harness had been chewed on. Was also assuming those sensors were compromised and not providing proper signal, thus the retardation. Once I got to the harness found only minor chewing, nothing all the way through and no contact points to cause a short; unless very, very minute. What I did find was right under the fire wall, on the bell housing, a breather valve was sitting on top. It was loose and could easily move around. Must have been set aside when a clutch replacement occurred. I could see that being picked up by the knock sensor. Would be weird but maybe there is the right amount of vibration and air turbulence once in boost. Another stretch.

 

Well, you can remove the main tensioner (which you will have to do any ways) and move timing over one tooth on the cams and see if all is good. If so then you know timing was off for whatever reason. At least you will know before taking everything out.

 

Could that be done without removing the cams? How would I go about doing this?

 

pull the lower tensioner out, that will give you the slack need to slide the chain over one tooth on both intake cams. Do one side at a time. Then reinstall the tensioner and spin the engine over by hand 4 revolutions on the crank. see if it all lines up. It looks like you will move the cams one tooth clockwise. Looking at you pictures, it looks like your about half a tooth off. This will be good practice once you're going back together. Make sure the truck is in neutral before you spin the engine by hand. Otherwise it will not turn. If you have a manual transmission. I have made that mistake.

 

OK, sounds doable. I was picturing the chain falling off the bottom sprocket and not getting it seated again. I will try to keep some upward tension on the chain after the tensioner is out.
4 revolutions should show alignment after the first 2, and the forth will confirm the alignment?
And yes, I found the "truck in gear resistor" yesterday.
Thanks!

 

Yes, two rotations will bring the cams back to top. 4 to double check. When you pull the cams out to do the repair use a bungie cord on the chain to keep tension. that way the chain will not fall off the crank. One side at a time.

 

I gave this a try last night. Thought I had it but no luck. It seems I need to pull slack from the right facing side/ bank 2, and pull the chain counter clockwise to the cams, instead of rotating the cams clock wise. Otherwise I end up where I started. The only way to achieve this is to slightly rotate the crank counter clockwise to create slack on the non-tensioner side. Then I can correct Bank 2 and move to Bank 1. Most of what I have read is to not rotate the motor backwards. But not sure if 1 tooth would matter?
With the tensioner reinstalled it barely extended any further, like a mm. So still minimal extension, no indicating the chain has stretched. I can only imagine it is just off a tooth.

 

There are a few updates to the OP. More comping. I decided that the chain is OK and moving on.
I completed installation of the new seals. Starting to put it all back together. Was a tougher job than I expected. Hope it doesn't blow up on start up!