DIY Coolant Valley Leak Repair

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Camera must have snaked over toward driver side.. I think what I am seeing in my pics is located here where arrow points.. of course.. probably lots more I can't see.

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Vendor of gasket option showed this tip for getting the PIA left rear intake manifold bolt out.

If you have Facebook

If not then screenshot from video

- Break loose with a T40 on a 1/4" drive

- Use 3/16 Allen T-Handle to back it out




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Removal of knock sensor connectors ... assuming the plastic is not too brittle for this method one can remove with a couple HF picks by simultaneously pushing tabs away from the bolt and pulling up.

Just used an example from a top of engine harness.

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Appears to be PN: 82712-50210

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82711-2A620

Pictures of a new rear harness connector and how they are put together and latch on loom and manifold bracket

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How common is this issue for the GX460? I've seen some threads stat that it almost a certainty at around 100k miles, and I've seen other groups mention how they've passed that mileage without any indication of a problem.

Also, is the procedure (listed on this thread) a definitive fix? Or will the issue come up again in another 100k miles?
 
Harper34 said:
How common is this issue for the GX460? I've seen some threads stat that it almost a certainty at around 100k miles, and I've seen other groups mention how they've passed that mileage without any indication of a problem.

Also, is the procedure (listed on this thread) a definitive fix? Or will the issue come up again in another 100k miles?
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Seems to be pretty common, especially with older and higher mileage. A few years ago, you only every heard about MY14 and below experiencing it, nowadays it seems that anything pre MY20 is not surprising. Coolant acidity appears to be a contibuting factor so the longevity of a 'fix' would depend on how often you change your coolant.
 
I read of a ‘20 Tundra with 3UR-FE on another forum needing to repair coolant valley leak..IIRC.. around 150k miles

I had 3 coolant changes within 96K miles
 
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Acrad said:
I read of a ‘20 Tundra with 3UR-FE on another forum needing to repair coolant valley leak..IIRC.. around 150k miles

I had 3 coolant changes within 96K miles
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I had a ‘16 Tundra w 3UR-FE, I found this thread while researching my “mysterious” coolant leak. Was planning to do this fix myself but ended up getting rid of the truck last year. This gasket is a huge step forward IMO.

Mine had major pink cotton candy globs on it, I’ll post some pics of if I can find them.
 
xychromosome said:
Seems to be pretty common, especially with older and higher mileage. A few years ago, you only every heard about MY14 and below experiencing it, nowadays it seems that anything pre MY20 is not surprising. Coolant acidity appears to be a contibuting factor so the longevity of a 'fix' would depend on how often you change your coolant.
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But what do people mean when they say "common?" There have been ~200k GX 460's sold over the last 6-7 years. How many of those are actually having problems with the valley plate?
 
Harper34 said:
But what do people mean when they say "common?" There have been ~200k GX 460's sold over the last 6-7 years. How many of those are actually having problems with the valley plate?
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It's an issue that will eventually occur with any of the UR family V8s.
The when just depends on age, cooling system maintenance, etc.
 
BC11SVT said:
It's an issue that will eventually occur with any of the UR family V8s.
The when just depends on age, cooling system maintenance, etc.
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It reminds me of a Subaru EJ25 head gasket seep. Every single EJ will need head gaskets eventually, usually between 100-150K miles. It's not a "end of the world" problem but a pretty expensive piece of routine maintenance. Much like the UR, the problem with the Subaru is coolant sitting on the gasket surface continually and slowly degrading the gasket coating. Here, it's the FIPG.

Subaru at least kind of "fixed" the problem with multi-layer steel head gaskets, but I'm not convinced that's a "final" fix unless the head/block interface is perfectly flat.
 
Acrad said:
Vendor of gasket option showed this tip for getting the PIA left rear intake manifold bolt out.

If you have Facebook

If not then screenshot from video

- Break loose with a T40 on a 1/4" drive

- Use 3/16 Allen T-Handle to back it out


View attachment 4090867
Click to expand...
For those without facebook, a few of us have posted how we got that bolt loose in this thread but I am sure it is buried. Lot of possible ways to get to that bolt. It would be cool if we could add this to the first post so folks don't miss it before starting.

Here is my solution:
jeremy j

Post in thread 'DIY Coolant Valley Leak Repair'

Now that I have mine finished up, I wanted to add my thoughts on something I saw discussed earlier in the thread.

@mcnaughty mentioned moving the heater hoses and using a 1/4 socket to get to the passenger rear intake manifold bolt. I removed the heater hoses the first time but the second time, I tried a 1/4 and was able to get to it relatively easy with this combination. Hopefully this saves someone the struggle of trying to get to that bolt.

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@ASUMTNEER shared their solution.
ASUMTNEER

Post in thread 'DIY Coolant Valley Leak Repair'

OK, quick update with some notes:

A 1/4" drive shallow 12mm socket with a 6" extension is the ticket for that back passenger side manifold bolt. I think it was hanging on by one thread the day before, when I was working with the 3/8" drive tools, and holding the manifold on. As soon as I backed that bolt off another turn, I was able to lift the manifold off easily. I'm still a little concerned about how I'm going to get that bolt back into place when the manifold is seated back down.

I disconnected the fuel crossover line on both sides of the manifold and didn't lose any gas. I believe...
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@hankstruck used the hex head. Seems like a good idea.
H

Post in thread 'DIY Coolant Valley Leak Repair'

All done- no apparent leak. That was a lot easier this time. Still a pain but not terrible. I will update with some very important ideas no one else has mentioned with some difficult parts.

UPDATE: Follow OP’s BRILLIANT and extremely helpful guide and photos. Here are my lessons that were only learned the 2nd time around.
  1. Do not do the radiator, water pump, belt, and tensioner at the same time. There is zero benefit and you don’t save time or coolant. I ended up having to do the CLV twice only to find out my new radiator was busted. So I had to do that twice too. Not my...
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Does either a driver or passenger side block coolant drain empty out enough to prevent overflow when cover is removed?

I was planning on draining radiator and just one of the block drains.

Thanks!
 
I drained the radiator and the pass side block drain and no issues with overflow. There will be some minor spillage as you disconnect the water hoses in the area but that's about it.
 
Probably not needed but seemed like a more controlled FIPG method and recommended by a Lexus mechanic on GXOR a few years back. It's been in toolbox the last couple years so will probably use it.

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J2Hundy gasket showed up today.. instructions recommend use with 1mm FIPG beads on both sides.. but dry option as well...

I plan to leave any of the previous foam material out in PCV valve area to make future borescope observations far easier for entire plate.

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