Usually coolant leak in the valley is the EGR cooler, pretty common.

 

 

My GX is at 70000 miles and it is having a coolant leak at the back of the engine. I tried to pinpoint the location of the leak but had a hard time.

Is there a coolant pipe down there or is this leak coming from the engine?
Can a head gasket issue leak coolant to outside of the engine? I do see some kind of grease like build u on my radiator cap.

Thanks

 

Are we looking from underside on driver or passenger side? Can you provide a more zoomed out photo as well for orientation? There are coolant lines that run to the AT thermostic switch as well that IIRC run on the backside of motor.

https://lexusgxor.com/_media/general:a760f.pdf

 

That first pic looks a lot like yours.

https://forum.ih8mud.com/threads/coo...-motor.937309/

https://forum.ih8mud.com/threads/kin...ngine.1004327/

It could be the coolant valley plate gasket leak

https://www.clublexus.com/forums/gx-...late-leak.html

 

Hi, when I purchased my 2012 (100k), there was a leak under the intake manifold. Changed all the manifold gaskets with new ones as well as the EGR Cooler in the middle. So far, everything is running ok and no more leak.

 

Here is a good article on issue:

http://carspecmn.com/gx460-coolant-l...in-the-engine/

GX460 coolant leak – a hidden leak from deep in the engine

The Lexus GX460 and the 4.6 liter 1UR-FE engine can, as it ages, develop a coolant leak from the valley of the engine. This can cause pooling of coolant in the engine valley, often running down the back of the engine between the flex plate and transmission, or down the transmission itself. Diagnosing the cause of the leak is tricky because it originates deep in the valley of the engine.

Underneath the GX460’s intake manifold, Lexus engineered a cover plate that houses a coolant galley to pass coolant between the cylinder heads and heater core. With the intake manifold and a great deal of secondary air injection tubes removed, you’re looking at something like this:



Valley plate leaking coolant


The circled areas indicate coolant leaking from the valley plate that covers this coolant galley. With the plate removed the leaks are a bit more obvious. In the photo below the plate’s perimeter is indicated by the red line:




Valley plate removed


And the leaks more closely:

Coolant leaks up close

The valley plate is sealed with Toyota’s special 1282B fix-in plate gasket specifically designed for Toyota cooling systems. It works incredibly well when applied properly. With the plate cleaned of residual gasket and resealed with fresh 1282B, the problem should not reoccur.

 

I just had my truck into the shop and it appears this is the most likely cause for my continued, albeit very slow, coolant leak. How much was the repair for you including labor? I am going with a second hand shop and they would need to special order the egr cooler, I was hoping to save some money and see if i only need to replace the seal (post #19) and not the entire egr cooler.


Anyone have any thoughts?

 

I serviced my car today at the dealer for the Coolant Leaks and found out that the Valley Plate and gaskets replacement for $1,600. Is this reasonable cost for 2012 with 117k?

 

Is this parts, labor or both?

 

Just paid the bill. The labor was $1,386 from $1,570 total.

 

I’m going to take a look when I get it back to see how bad it is. Really don’t want to spend $1400 right now if I can avoid it.

 

Since this is a known issue any possibility of Lexus covering this in the future?

 

seems sort of rare on here at least. Couldn’t find much info when I did a search. I don’t see them covering something uncommon.

 

Yeah.. I would call water pumps a little common considering how many of the regulars have dealt with it ....including myself.... the valley leak quite rare but can occur.

I never monitored mileage on those with valley leak. I wonder if more common over 100K miles with stock coolant?