Kind of "Mystery" Coolant leak back of engine (heat exchanger valley leak)

[kms254]

It's most likely the culprit. I had to put a borescope from the back of the manifold to see the pink crust. You do not need new intake gaskets for this job. Two Orings and the proper FIPG.

Borescope came in this morning. Confirmed the leak.

Passages side front:

Passenger side looking back:

Drivers side:

It looks like it’s leaking near the front more than the back.

I don’t see enough to justify the loss I’ve seen so I assume there is more in the back but seeing what I see now there is no reason to investigate more..

2009 LX 138k miles.

 

[Supra88]

Borescope came in this morning. Confirmed the leak.

Passages side front:
View attachment 2844665

Passenger side looking back:
View attachment 2844666

Drivers side:
View attachment 2844667

It looks like it’s leaking near the front more than the back.

I don’t see enough to justify the loss I’ve seen so I assume there is more in the back but seeing what I see now there is no reason to investigate more..

2009 LX 138k miles.

It will likely be considerably more than you're seeing. Keep in mind that what's leaking is evaporating and leaving a precipitate behind.

 

[anthracite]

It will likely be considerably more than you're seeing. Keep in mind that what's leaking is evaporating and leaving a precipitate behind.

Yeupers. Mine had so much crust there that I had to use a pick and wet vac to clean it all up. What a mess. Don’t understand why Toyota didn’t use a gasket here. If it happens again, I may just pay to have it fixed lol.

Steve

 

[BigMF]

Still not clear to me. You need to get that water pump pulley out of the way.

Noob mistake! Was ignorant about the actual location of the water pump. It was indeed the water pump and have finished up the radiator, water pump, etc. job. Thanks for trying to help!

 

[bloc]

Noob mistake! Was ignorant about the actual location of the water pump. It was indeed the water pump and have finished up the radiator, water pump, etc. job. Thanks for trying to help!

Good to hear!

Once you got a better look at it, no valley leak I assume?

 

[BigMF]

Good to hear!

Once you got a better look at it, no valley leak I assume?

Correct! Thanks again for jumping in to help.

 

[anthracite]

Correct! Thanks again for jumping in to help.

Best news of the day!! Haha.

Steve

 

[kms254]

Picked up the sealant and o rings today. Got some coolant as well to just have on hand. I’ll likely start Friday.

The Lexus dealer was a ghost town with the lot nearly empty…

 

[pvchaitanya]

I have a similar issue. I got my lx 570 2011 recently (3 months old) and I see that coolant level dropped, although the engine temeperatures didn't go high.
I was trying to replace differential fluid today and remove the covers below and found a lot of coolant crust here. attached are pics and videos. I only see it in the bottom to the rear. I see the crust right beside the engine oil pan. its more on the side where I think torque converter is.
Here is the video link:
iCloud - https://www.icloud.com/attachment/?u=https%3A%2F%2Fcvws.icloud-content.com%2FB%2FAWCkJF1t9M2KzcYOEQFpcwzA1xQAAaCGqdOAMd5-UQ1FMD6kK9PiaOx6%2F%24%7Bf%7D%3Fo%3DAqrQKUw8VC8IuL38s-3HU5sTMGon9DFqEUp45-H1qbzw%26v%3D1%26x%3D3%26a%3DCAoglkKICbA_4B9al-uikoxkSYvZ1UsQQOr5-IbAXNRecbUSdhDaj_GY1S8Y2p_s7N4vIgEAKgkC6AMA_xmFfBpSBMDXFABaBOJo7HpqJbkZmjRgA7zLA1CnxSyaETmjRxqz0RXsbJscMit_9LO7mw2RwbhyJX4Sr-6XPZjqC9DygzWJNWeSzxsAzO5UAY4C6Ox-FsQkcEFmJyg%26e%3D1640368902%26fl%3D%26r%3D12A76509-91B3-4F8D-848C-D8D6F4AEC822-1%26k%3D%24%7Buk%7D%26ckc%3Dcom.apple.largeattachment%26ckz%3D5E28357A-F068-4D6B-8FC2-4354C9649689%26p%3D59%26s%3D8diQ1qWHt0t1cxIf5xjEOy8M_FU&uk=z-1WL16Pma31rUjwAGFgaw&f=IMG_5015.mov&sz=28135481

 

[kms254]

Dumb question, intake manifold bolts, are they T35? I have a T30 and T40. The 30 feels a bit loose and the 40 doesn’t fit.



Update: T40 was it, just had some debris in the head that made it seem to big

 

[kms254]

Do I have to remove the SAIS valves before I remove the crank case oil separator? I’m getting interference at these two locations.

 

[kms254]

Do I have to remove the SAIS valves before I remove the crank case oil separator? I’m getting interference at these two locations.

View attachment 2848847View attachment 2848848

Short answer after removing the two bolts to the tube that goes to the exhaust manifold and the three bolts for the SAIS everything easily came apart. Hopefully my notes will help the next guy.


Two observations:
1) there was for sure a rodent living in there at some point in time…
2) I think most of my leak is from the oring or the very front part of the valley plate

My stopping point for the night…

My work setup…

 

[kms254]

Today I didn’t spend much time on the project, but I got the SAIS valves out. For me the hardest bolt was the passenger side front one, but it only took me 20 minutes to pull the entire unit. After reading the horror stories on here I thought it would be worse. I only used standard a 10mm ratcheting wrench.

I also got the coolant drained from the block. As far as I know except for radiator and water pump work the truck has never had a flush at 138k miles. I jacked the truck up all different ways to get as much out as I can.

I did notice some black flakes in the coolant which I’ve never seen draining the radiator or doing the water pump.

 

[Supra88]

Good work. That passenger side bolt can be tricky.

 

[kms254]

Skipped working on it on Sunday, and did a bit between work and dinner.

Stopped draining the block. Got the wheels back on and the LX sitting on the ground.

Removed the valley plate. Luckily draining the block kept it from pouring out all over the place!

My fluid pump showed up right in time and I use it to drain the left over coolant in the valley.

Now it is time to clean everything up and re assemble.

 

[pvchaitanya]

Going to chime in with a tip and a question.

For the tip: A 10mm dog bone makes getting the air injection valves out easier, particularly when trying to break loose the two rear bolts.

View attachment 2621055

For the question: What are folks using to remove residual sealant? I have scrubbed with chlorinated brakleen and managed to get most of the chunky stuff off. There is a thin film residue that I cannot seam to get to go. As a corollary; has anyone foregone the $$$ sealant and swapped to the toyota "red" coolant, rather than the SLL "pink" coolant which seems to require the special sealant?

this wishbone tip is awesome, this should solve the issue with wiggling with tiny fingers. I will line up all these tools before attempting my fix.

 

[TLC2013]

Has anyone seen a major cooling failure and immediate loss of fluid with this leak? Doesn’t seem so as I haven’t seen anyone post this experience. My 2013 with 105k has been slowly losing coolant from the over flow. Been topping it off for the past few months and started with replacing the overflow cap which was missing its gasket, unfortunately this didn’t do the trick.
finally Poked around with a borescope. There are few spots of coolant residue on top of the coolant valley below the intake manifold. Trying to make it to the end of the month to get this repaired. Waiting on parts and the sealant.

 

[kms254]

I got back to it today, spent half a morning cleaning off the old fipg from the mating surfaces and all the bolt threads. Did a few dry runs and then did the install..

Cleaned and ready

Installed and torqued down!

 

[Supra88]

Has anyone seen a major cooling failure and immediate loss of fluid with this leak? Doesn’t seem so as I haven’t seen anyone posted this experience. My 2013 with 105k has been slowly loosing coolant from the over flow. Been topping it off for the past few months and started with replacing the overflow cap which was missing its gasket which unfortunately didn’t do the trick.
finally Poked around with a borescope. There are few spots of coolant residue on top of the coolant valley below the intake manifold. Trying to make it to the end of the month to get this repaired. Waiting on parts and the sealant.

View attachment 2855571

View attachment 2855572

You'll be fine until your parts arrive. A lot of these coolant valley leaks persist for years before they're addressed.

 

[bloc]

You'll be fine until your parts arrive. A lot of these coolant valley leaks persist for years before they're addressed.

Agreed.