Kind of "Mystery" Coolant leak back of engine (heat exchanger valley leak) (4 Viewers)

[GrouchyTech]

Wouldn't the valley plate need to be resealed if you pulled the heads to do a head gasket? I would think you'd need to remove the heat exchanger cover as it's called in the FSM to get the head off? It shows as sub steps in the FSM (under 7. REMOVE VALVE LASH ADJUSTER ASSEMBLY) but I know the FSM often calls for a lot more removal than is actually necessary

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You can definitely replace the head gaskets without pulling the valley plate.

 

[bloc]

Now that I think about it, I don’t see too many valley leaks relative to the number of vehicles with this engine that we see on a daily basis.

That was my gut feeling on this. It sounds common given the frequency with which we see these on here, because people post asking for help or with their disappointment, but probably not even close to a majority of the engines overall.

 

[mfeferman]

Word of caution with the above. My leak was at the front USA passenger side of the heat exchanger cover. It would have been difficult to find with an inspection camera from over the top of the PCV valve. I definitely didn't think I had a leak until I got my intake manifold off and could see the pink crusties on that side. Getting the intake manifold off is a pretty easy task if you really want to do a good inspection. FSM calls for replacing the intake manifold gaskets, so that's the only expense if you go that route by the book. I've read about people not replacing and just reseating, I can't comment on which way to do that. I replaced the gaskets.

You can see that location with a camera, but there is no official gasket other than the new formula FIPG, but there is a person who contracted with someone to make a gasket and you can buy it online.

 

[mfeferman]

That was my gut feeling on this. It sounds common given the frequency with which we see these on here, because people post asking for help or with their disappointment, but probably not even close to a majority of the engines overall.

I think it’s more in the 2013-2018 years.

 

[linuxgod]

That was my gut feeling on this. It sounds common given the frequency with which we see these on here, because people post asking for help or with their disappointment, but probably not even close to a majority of the engines overall.

I bet a lot of 3URs have it, but it’s slight and if you’re not losing much coolant from it for a long time shops may just top off the overflow at oil change time and barely note it.

I think at 174k I’ve had every common failure at this point except starter. I’d call head gaskets and SAIS issues relative rare despite what we see on this forum - more common than we’d like to see but statistically small. My local dealer has 15-20 shop bays and the service manager and I will chat about what they see as regular issues on this platform (LC, Tundra, Sequoia) and the valley plate was so common for them their labor rates were a few hours less than the book rate

 

[mfeferman]

Leaking Valley Plate fix · Nov 6 – 14, 2024 📸

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[Cruisin911]

I bet a lot of 3URs have it, but it’s slight and if you’re not losing much coolant from it for a long time shops may just top off the overflow at oil change time and barely note it.

I think at 174k I’ve had every common failure at this point except starter. I’d call head gaskets and SAIS issues relative rare despite what we see on this forum - more common than we’d like to see but statistically small. My local dealer has 15-20 shop bays and the service manager and I will chat about what they see as regular issues on this platform (LC, Tundra, Sequoia) and the valley plate was so common for them their labor rates were a few hours less than the book rate

My 2011 had a SAI valve failure and the valley plate leak. All at less than 100k miles.

 

[mfeferman]

My 2011 had a SAI valve failure and the valley plate leak. All at less than 100k miles.

I should have done the EGR delete when I did my valley plate.

 

[lx200inAR]

You can see that location with a camera, but there is no official gasket other than the new formula FIPG, but there is a person who contracted with someone to make a gasket and you can buy it online.

The intake manifold gaskets according to Toyota are a one time use part. The heat exchanger gasket is an after market part. It is what I used to repair my leak. Based on where the forward most foam is installed, I can’t imagine you’d see where mine was leaking, but I’m having trouble visualizing, so you may be right. Certainly worth a try if you have a camera. And considering how cheap they are on Amazon these days, everyone should have one.

 

[mfeferman]

The intake manifold gaskets according to Toyota are a one time use part. The heat exchanger gasket is an after market part. It is what I used to repair my leak. Based on where the forward most foam is installed, I can’t imagine you’d see where mine was leaking, but I’m having trouble visualizing, so you may be right. Certainly worth a try if you have a camera. And considering how cheap they are on Amazon these days, everyone should have one.

Oh, you used that after market gasket??!! Awesome. I literally saw it only two weeks after I did mine and wished I had seen it before. I’m really curious to hear your thoughts on how awesome it’s sealed considering how thin the FIPG is in some places for that heat exchanger.

 

[lx200inAR]

Oh, you used that after market gasket??!! Awesome. I literally saw it only two weeks after I did mine and wished I had seen it before. I’m really curious to hear your thoughts on how awesome it’s sealed considering how thin the FIPG is in some places for that heat exchanger.

I decided to install it dry with no gasket sealer. It’s been about 6 months and everything has been fine so far.

 

[mfeferman]

I decided to install it dry with no gasket sealer. It’s been about 6 months and everything has been fine so far.

That's great to know.