tystaco

Just buttoned my valley plate leak back up yesterday using the ih8mud link provided by Arcad. Just tedious, probably had 8 physical hours into it, including the 1 hour trying to fish my 10mm wrench out from its wedged spot above the transmission/rear main. A couple of things to note from the ih8mud....to avoid the coolant on your serpentine belt, just drain the radiator before you disconnect the coolant hose on the bottom of the throttle bottle. Also, the 10mm bolt on the back of the manifold that holds the gas crossover isn't too bad to get off if you can disconnect the two wire harness clips, then just unbolt the manifold and pull it forward giving you access to the 10mm bolt...otherwise I think it is literally impossible to reach or even feel. Also, toss out those foam blocks...they were hiding the problem...at 125k...this leak has clearly been around a long time as the foam was deteriorating in it...now I can see to the PCV valve with a flashlight and might be able to spot a problem. The service history on my rig showed Lexus replaced a radiator not long ago because of a coolant leak...I think they took the cheap route to appease the PO or they had no idea what they were looking for.

Starting the car up after putting it all back together was incredibly nerve racking hoping a bunch of coolant wouldn't pour out....had a mild panic attack when I backed down the driveway and had a trail of coolant (luckily it was just the remaining coolant on the skid plate tipping off on my angled driveway) So far so good....Saved a bunch of money and just took my time over a week grabbing an hour where I could.

Acrad

L3xusGX: I can't say... I've read about some 3UR-FE up to about '18 and 1UR-FE it seems about '15 but this could be an age & mile thing as well.

tystaco: Is it this wiring harness?

or further down the back?

tystaco

Acrad, that is the one. And in reality looking at it again, it would probably be easiest to reach both harness connections and the 10mm bolt but unbolting the manifold and lifting it off of the front two studs to give yourself even just an inch more room. I was able to get my thumb on the harness clip release and push the harness off of the metal tabs with my other hand alongside the harness...but overall my hands are fairly dainty so I would definitely try lifting the manifold slightly forward with these all still connected. I followed the link on ih8mud and didn't bother reconnecting any of these...they didnt move anywhere after free hanging for a week and get wedged in well by the manifold.

L3xusGX

Ok, I'll have to wait it out then. That said, you'd think they have it worked out by now and especially given how long this same engine has been used on the GX.

Acrad

Another member of GXOR also recommended replacement of these two hoses

Schematic

1629438010
1628238050







[Removal]





[Reassembly]

Nytron

Coolant valley leak is not rare on the GX 460. I've seen this more often than not on high mileage GX 460s. Just a matter of time, it's a design flaw.

JonGX

mine goes to the shop tomorrow with this leak. i only noticed when doing some suspension work (strut replacement) and had the front end up in the air. i saw a small drip coming down the bellhousing onto the skid plate.

it's also going in for the timing cover leak that is now present on both sides of the block (where each head mounts to the block). it has been 'seeping' for some time now and lexus keeps sending me home with a TSB stating that this is normal. i still dont understand how finding oil OUTSIDE the engine block is considered normal. the leak, excuse me, seepage, has now gotten significantly more noticeable.

ive asked the dealer to give me a price on fixing the valley plate leak while they are doing the warranty work on the timing cover. I know the timing cover doesnt require removed of the intake manifold, but i'm hoping the joint repair will cut down on the number of hours needed. if not, ill do the valley plate leak by myself

L3xusGX

What's the mileage and year of your GX?

JonGX

2014 with 73k.

the dealer, to my surprise, is covering the coolant leak. They claim that the timing cover is ‘only seeping’ and not actively leaking and will continue to monitor. Not my preferred outcome but I’m not going to push the issue at this time bc I appreciate that they are covering the coolant leak which is a time consuming repair

edit: the timing cover issue was escalated and Lexus corporate (not the dealer) is denying coverage of the repair. It’s well documented in my service history that this issue started while the truck was still under a powertrain warranty so I’ll keep monitoring it and may open a formal case as some point in the future. I’ve been very happy with the service department at this dealer over the past few years.

LokiGx

do you have any warranty or is the dealer doing it out of good will since its a common problem on the 460s?

I have a 11 with 142K on the odo, noticed the valley leak after I bought it at 115K. Over the 25k miles from when I notices the leak, just topped off the coolant during every oil change and so far it has taken only a gallon in 18 months and 25K miles.

I'm debating whether to get the leak fixed or leave it for now till the leak becomes bigger.Since the leak is external to the block, do we see any issues on running it long term?

I have been hearing quotes from 1k-2.5k$ for the valley leak, how much did your dealer initially quote for the valley leak fix?

thanks!

JonGX

i am no longer under any warranty, but have taken the truck to this dealer for service since i got it in 2017 with 45k miles. to be honest, I'm not sure why they offered to cover the coolant leak. i didnt specifically ask for it to be covered - i had asked for a quote on the repair cost assuming they'd be doing the timing cover.

in your situation, my only concern with waiting would be if at some point a very small leak becomes a very big leak very quickly and you loose a large amount of coolant while driving. i dont know how quickly this type of leak typically progresses, but it's not going to magically heal itself over time so it seems like only a matter of time before it gets worse. i dont think the leak itself, provided it stays small and you keep up on coolant levels, poses any long-term risk.

i didnt get a quote on the cost to repair the leak because they offered to cover it before i saw an estimate. based on the writeups ive seen online, my guess would be in the $1500-$2000 range as you suggested. the parts are relatively cheap (assuming its just the gasket and not the EGR cooler itself that's leaking) so its mostly a labor job. not sure what the book time is for an experienced tech, but i had planned on it taking me 6-8h over two days to complete.

Rodinator

You can usually get it fixed at a Toyota dealer for much less. I had mine fixed at a Toyota dealer for 1100$ and change I can't remember the exact amount. I had it fixed on my 2011 at 145k, I purchased the vehicle with the leak present. As far as how long, reading and reading about this on Tundra's and GX's its really a crap shoot. They can go a long time as a minor leak and they can then grab another gear so to speak really quickly. It really depends on how much you depend on it how close attention you pay to the level, how much risk you are willing to take if you overheat it.

L3xusGX

Got it and now wondering if the extended warranty would have made sense between this issue and the oil seepage filling the spark plug wells. I'm not too concerned at the moment since my 2021 only has 6K on the odometer but it's certainly given me something to think about. Maybe the redesigned twin turbo V6 won't have any of these issues and therefore I can simply trade-up?

JAYIN

So after about 10 months from replacing my wife's radiator in her 2012 GX 460 (160,000 miles) I recently got some brutal news from the dealer regarding a valley plate repair. After noticing that the air was not blowing cold and the thermostat needle was pinning back and forth like a hockey puck.

I first noticed there was no coolant before driving it over to the dealer to at least see if it may have been something like a water pump or thermostat. The dealer had advised me after about 4 hours that the plate itself wasnt cracked BUT the reapir of new sealers, gaskets and o-rings would cost roughly $2300.00.

Reason I am asking the forum wizards here is a couple of things:
1. They have already provided me a loaner (5 days) and I am at least getting the warranty of 2 years after they do the work. So is this worth it?
2. Has anyone had experience of getting a better quote from a non dealer and what roughly has that pricing been? I haven't seen a dealer quote for this job in some time on this forum but I wanted to see what you guys thought before proceeding.

Thanks so much this is in Nevada as well.

WRD4chano

I just paid that in labour to get my coolant valley, radiator, condenser and trans drained and filled.

the issue is, finding a competent and trustworthy independent mechanic.