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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?
yeah I wonder as well. I had the coolant changed at 85k at Camelback Toyota in Phoenix and they didn’t say anything. I have since moved or I would take it back there. That’s the best dealership I’ve had the pleasure of using.
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
Has anyone done this repair DIY recently? When changing the serpentine belt recently I just discovered my GX 2015 with a little over 100k has no coolant in the overflow reservoir and there is a slow leak on the block of the engine (dry pink) so I assume the coolant valley plate leak is just happening.
Do I need to order other parts that will break in the process when removing the valley ? I also assume that I need the sealant only to fix this:
BLACK LIQUID GASKET FIPG - Lexus (00295-00103)
as the 1282B is not manufactured anymore. Please chime in.
Is this problem on the earlier produced 1UR-FE engines, or common in all years, just higher probability of leaks with increased miles ??
maybe depending on the area you live as well? We got ours in Phoenix and I swear it did have a little coolant leak. Since I’ve lived in Ohio the reservoir hasn’t needed to be topped up at all. Dealer found it when we got the 2nd air pump replaced but I don’t think it’s leaking anymore.
It seems that multiple vehicles with the same engine have the same problem - its mileage, happens around 100k. I am not 100% sure it is this type of leak, but it leaks somewhere from the block or from beneath one of the cylinder heads and drips on the front of the engine.
It is just an exterior leak from what I have seen. Coolant level in your recovery tank is a good check item as well. Water pump shows itself a lot easier with pink stains on front skid or cotton candy around the water pump that is visible from topside. If coolant valley is draining off rear may be harder to notice unless you are looking on back & underside of motor or coolant loss from recovery.
Not saying coolant valley leak can't come off front but I hear of more reports being seen off the backside & below.
Is this problem on the earlier produced 1UR-FE engines, or common in all years, just higher probability of leaks with increased miles ??
My 2013 ISF had this exact leak. I noticed mine because my heater stopped working. The technician at Park Place Lexus in Grapevine, TX said this happens often with that type of V8 engine, they used the wrong type of silicone (or something like that when manufacturing the engine). Lexus HQ claims they have not had many complaints as I contacted them trying to get them to pay me back for the almost $2500 worth of work. If you want to file a complaint so they know about this issue go here- Lexus at 1-800-255-3987, Monday through Friday, 7:00 am to 7:00 pm, or Saturday, 8:00 am to 5:00 pm, Central Time, or use the following link: http://bit.ly/ContactLexus I filled out the form as subject "Engine Valley Coolant Leak V8" Maybe if enough people fill this out they will realize that they need to fix it and do a recall. You HAVE to state "I would like to open an enquiry regarding the Engine Valley Coolant Leak." As the reply email will just say sorry it happened. If you request someone to call you then they open a case. You need to talk to a Case Manager. Lexus definitely makes this difficult to file any complaint with them, however this needs to be addressed.
Response: "Nope. You have to remove the EGR cooler which is held by 2 12mm bolts for the cooler itself and 2 12mm nuts for the EGR pipe that goes to the rear and 2 10mm nuts for the front. The heater pipe which is held by 2 10mm bolts, the oil separator which has 4 10mm bolts. Once all that is removed then you will get to the knock sensors. Knock sensors are 4 sensors held by a 12mm bolt each and the sub wiring harness. Once that’s removed you will see the cover. Cover is held by 12mm bolts and 2 12mm nuts and 1 10mm bolt. Once the bolts and nuts are removed you need to remove the threaded studs with a external torx socket E8."
"Here you can see the EGR cooler (metal square)"
"on the GX we normally do 6-8 hours. The LS and ISF is more complex due to the direct injection."
"2-3 gallons of pink Toyota SLLC (coolant) and one tube of 00295-00103 FIPG."
"the third one down EGR cooler No1 you only need one gasket"
Response: "Nope. You have to remove the EGR cooler which is held by 2 12mm bolts for the cooler itself and 2 12mm nuts for the EGR pipe that goes to the rear and 2 10mm nuts for the front. The heater pipe which is held by 2 10mm bolts, the oil separator which has 4 10mm bolts. Once all that is removed then you will get to the knock sensors. Knock sensors are 4 sensors held by a 12mm bolt each and the sub wiring harness. Once that’s removed you will see the cover. Cover is held by 12mm bolts and 2 12mm nuts and 1 10mm bolt. Once the bolts and nuts are removed you need to remove the threaded studs with a external torx socket E8."
"Here you can see the EGR cooler (metal square)"
Dang, great shot of the foam piece that obstructs the PCV. Best picture I've seen of it yet... looks like you could tear/pull it out to access the PCV.
I just discovered I have this leak on my 2011 GX today.
Every time I get fuel I check fluids and do a general inspection while the tank is filling. It is a habit I will probably never break since living in, and traveling the country in a VW campmobile for a few years several decades ago. If you didn't check your VW out at every possible opportunity, parts would fall off, or you would be stranded or both.
I filled up with fuel a couple of days ago and noticed the coolant level was about halfway between the L and f marks in the overflower reservoir. I usually fill the reservoir and all fluids for that matter as needed, with each 5,000 MI service. The last couple of services I had added a small amount of coolant to the reservoir and didn't really think much of it. Although, I should know better that coolant does not get consumed or just disappear without a reason.
I drove about 300 mi and then came home to do the 5,000 mi service and tire rotation etc. When I got home, the fluid in the coolant reservoir was below the L mark!!!
I changed the oil and rotated the tires and crawled around underneath it to look for any evidence of leaks. Water pump dry. Hoses all dry. Radiator seams dry. No pink or other fluid on the bottom of the skid plates or on the transmission bellhousing, all dry. Also, no noted antifreeze smell.
So I did some searching for "UR engine coolant leak" and I got a lot of pages on the IS engines having this problem.
I have one of those cheap flexible inspection cameras that runs from Wi-Fi to Android so I hooked it up and put it in the small recess under the intake manifold just medial to cylinder number two and posterior to the throttle body. Snaked it in there, and you can't see a lot of places and recesses, but sure enough, found my lost coolant.
it's a pretty slow leak, or at least it was until this week. I would encourage everybody to check it out, or if you don't have stuff to do that, have a reputable shop give it a look if you're around 90-100k. Most of all, check your coolant reservoir! If it's dropping slowly, something is going on and it may not be obvious for quite a long time!
Best thing is I have a 10-year 100,000 mi warranty on mine and currently have 99,250 MI and until January 1 2021 til it expires. They say they are going to cover it!
Will replacing pink with red coolant prevent this leak
Will replacing pink with red coolant prevent this leak. Saw on one of the GSF video, guy saying that pink is not compatible with silicone used in the gasketing compound. He was replacing OEM pink with old red OEM coolant at 26k miles on GSF. Any one heard this to be true.
01-06-20, 02:20 PM
