Valley Plate Coolant Leaking (2 Viewers)

[jmanscotch]

Smelled coolant the other day and just had time to look over the rig and see what might be up. Found this around the transmission:

Do you think I have a valley plate coolant leak?

Just kidding, it’s abundantly clear. Just wanted to share since I haven’t seen too awful much in regards to this, happens but isn’t crazy common yet it seems. I just did an oil change and greased the u-joints/etc about 1,000 miles ago and saw nothing down there. Coolant was low, topped it off and it’s at L again today. Seems to have potentially been leaking slow and got worse fast.

2010 with 110K on it. Now to put a parts list together and tackle this, water pump and radiator in one go, all in winter time without a garage, my favorite.

Can anyone offer a recommendation on a good OE parts supplier they like? I’ve seen mention of several dealership parts departments and such, just looking for one someone’s used and recommends.

 

[Acrad]

Owner over on CL was able to see the leak on his GX with one of those cheap USB borescopes.

Coolant Valley Plate Leak - ClubLexus - Lexus Forum Discussion

GX - 2nd Gen (2010-2023) - Coolant Valley Plate Leak - Does anybody experience coolant valley plate leak for GX460? Dealer told me this is common problem for high mile GX460 engine. I have 2010 GX460 with 93000miles.

www.clublexus.com

 

[jmanscotch]

Owner over on CL was able to see the leak on his GX with one of those cheap USB borescopes.

Coolant Valley Plate Leak - ClubLexus - Lexus Forum Discussion

GX - 2nd Gen (2010-2023) - Coolant Valley Plate Leak - Does anybody experience coolant valley plate leak for GX460? Dealer told me this is common problem for high mile GX460 engine. I have 2010 GX460 with 93000miles.

www.clublexus.com

Appreciate it, Acrad. As far as I can determine, there’s really no questioning what the cause is with it leaking down the back of the engine only. Nothing visible on the top side points to any other leaking areas.

Working on compiling a parts list and ordering everything and then will tackle it myself along with some other cooling system preventative maintenance while I’ve got the system open. I’ll take notes and share here when the time comes, hopefully within the next 3 weeks or so.

 

[Washingtontaco]

Thanks in advance for posting the repair.

 

[Acrad]

Post 37 has some good tips from a Lexus tech

Coolant Valley Plate Leak - ClubLexus - Lexus Forum Discussion

GX - 2nd Gen (2010-2023) - Coolant Valley Plate Leak - Does anybody experience coolant valley plate leak for GX460? Dealer told me this is common problem for high mile GX460 engine. I have 2010 GX460 with 93000miles.

www.clublexus.com

 

[jmanscotch]

I stopped by the local dealership early this week and reminded myself that their parts guy is a prick. Besides being overall bothered by me being there, the parts quote I got was $450, for seals and a waterpump. The SA I dealt with during my previous visit was cool though, printed me off a workup from the last person that had the dealership repair their leak and it had parts numbers and costs. Parts $114, labor $1,250 for the valley pan.

I ended up ordering most everything from myLparts.com which is a dealership ran by Lexus of Roseville near Sacramento, CA. They had good prices, fast and fair priced shipping.

All gaskets needed, and some extras I thought I might need on hand (~$30 worth), plus a water pump and FIPG, was $242 shipped ($13 shipping) with a 10% off discount with code CL5. So way cheaper than local. I ended up with coolant and a Denso radiator off Amazon as MyLParts wouldn’t ship the coolant and didn’t have the radiator. Those were about $240.

I didn’t go for a few parts most would probably replace while doing the rest, like a drive belt and tensioner pulley, etc, because mine are good and easy to get to down the road when/if needed.

Ordered the parts yesterday and they’ll be here tomorrow apparently, if true then very fast turn around for MyLParts and it means I’ll dive into it a bit tomorrow and then Saturday.

I’m not going to do a full documented DIY, it’s not a hard job it seems, but I’m happy to make notes and cover any specific areas anyone might be curious of. I’ll touch on any notable issues and detail what parts I actual use and what I feel might be used by some doing the repair.

 

[jmanscotch]

Was just able to air down the tires and remove everything off the rack to squeeeeeeze the GX into the garage.

Got to work and almost have the intake manifold off, fighting the large wire loom that runs along back of the manifold, can’t get it to disconnect so calling it a night.

Here’s better evidence of the leak.

 

[jmanscotch]

This repair sucks lol

 

[Acrad]

I'm rooting for you. I know this would definitely be at least a weekend project for me.

 

[jmanscotch]

That moment when you put it all back together and fill it with coolant and it immediately starts pissing coolant from the back of the engine

I thought I may have got a little coolant on the FIPG right before I put the plate on, but I convinced myself I was being paranoid and pushed on. Now I’m certain I did and the gasket didn’t seal to the surface.

I guess it’s time to tear it back down and do it again. I guess the good news is I’m familiar with how to get it all apart now and any stubborn clips are already broken and out of the way. Plus the water pump, thermostat and radiator are good so it’s just the valley pan to redo. Ugh.

 

[Acrad]

Did you remove all the coolant that was in this area prior to sealing? I've used small shop vac on other motors.

 

[jmanscotch]

I didn’t remove all of it, but sucked it down to an inch or so below the plate mounting surface.

I placed the o-rings for the transfer pipe in the valley though, to get them nice and lubricated with coolant to ease install, and then put the FIPG onto the surface, then grabbed the o-rings out of the valley pan to put them on pipe. When I was grabbing them, I was bent over the truck and my elevated work stand slipped under me and my hand splashed the coolant in there a bit. I couldn’t tell for sure if I splashed any on the gasket material, but thought I might have. I looked and didn’t see any signs of the gasket material being wet so I convinced my self I was being paranoid and didn’t want to scrape the FIPG off and clean it again so I just installed the plate in a hurry (since you only only have a few minutes).

I’m going to remove the intake and fill the system with coolant and see where it’s leaking from to confirm it’s the contaminated FIPG that’s the issue and not a cracked line or EGR cooler connection issue before I move forward with assuming it’s the gasket that didn’t set right.

 

[jmanscotch]

Confirmed it’s just not a good seal between the valley plate and block. Took intake manifold off and put more coolant in and can see it simply filling up the valley pan via the plate seal. Can’t see any leaking anywhere else (EGR cooler connections or transfer tube connections are the other other coolant carriers in there).

Lesson learned: as good as FIPG is, it does not like any contamination, coolant included. Before putting the plate on, blow out the plate mounting holes to get the coolant out of there (I had done this) and soak/vacuum up all the coolant around the valley to avoid any accidental contamination. Plastic razor blade the sealing surface and prep with non-residue cleaner (I’m using un-chlorinated brake cleaner).

The good news is it only took my 20 minutes to get to this point again. I’ll update with how long it takes to do the entire valley pan gasket job a second time lol.

It took me about 14 hours total to do the valley pan, water pump, thermostat and radiator the first time. I work pretty medium paced, bordering on slow and take breaks because my back sucks and needs rest at times. I’m guessing valley pan second time will be about 3 hours total.

 

[carlos33018]

Wao this is an amazing thread. When you can, take pictures of the challenge areas and throw a little snippet on how you got around it. I’ll probably have to do this myself as well.

 

[jmanscotch]

Wao this is an amazing thread. When you can, take pictures of the challenge areas and throw a little snippet on how you got around it. I’ll probably have to do this myself as well.

I decided to go ahead and write up a DIY on the repair. I think enough of us are going to eventually face this issue and now doing the job twice (let's hope not a third time) I've happened to take enough pictures and really get familiar with the job to hopefully share some of what I learned, what I messed up and tips/tricks.

I'm letting the FIPG sit overnight and will reassemble everything else tomorrow after work. I need to take some additional pictures during reassembly, now that I decided to write it up, then I'll post a new thread with it all in one spot.

It's not a bad job, a bit frustrating and if your GX is lifted and you have a bad back like me, you'll spend entirely too many hours bent over trying to reach the intake area and the tiniest clips/bolts at the back of the engine. It's just nuts, bolts, hoses and sensors though, all stuff anyone can remove with basic tools.

A little update on the leak after repair though. I really thought it was the FIPG leaking due to the coolant contamination, but upon pulling the coolant transfer piping off to try again, I noticed one of the o-rings was kinked and pinched. I don't know for sure, but I now think it was potentially both. The o-ring makes more sense as the source of the leak, post "repair" as it'd allow a large quantity of coolant to leak instantly, were as the potential issue with the FIPG would probably leak some, I just don't think it'd spew it as fast and as much as I was observing, considering I was only filling the coolant back up and it wasn't even circulating in the engine yet.

The bottom o-ring in this picture (which would be closer to the radiator vs the back of the engine). I think the second way I installed this transfer pipe worked much better than the first, which I fought with a bit, though tomorrow will tell for sure.

As a side note, I'm pretty confident that professional mechanics are doing this job in 3 hours or so, not the 6-8 hours the book calls for. I know that's not uncommon in the industry, but wanted to note it if anyone was curious.

 

[lndshark]

Sorry to hear this didn't work out the first time around. In addition to getting as much coolant out of the valley, I suggest blowing out the bolt holes with compressed air if you have access to it. And let the FIPG cure as long as possible. Maybe tend to other parts of the job if you can to give it as much time before you fill the system.

 

[jmanscotch]

Well, wrapped up the job tonight, not bad the second time through. All in all, the second time around on the valley pan only took me about 4 hours, including refiling and bleeding the cooling system. Brought the engine up to temp, no leaks, no codes upon restart, all good on that front.

Now, I must've spilled just enough coolant on the belt to cause a belt squeal (will try to wash off, if nothing else I'll replace it) and the more notable issue is I'm hearing a faint bearing grind that comes and goes in severity. I also snapped off a brittle secondary air injection pump hose, that I simply electrical taped up for now ($45 part, but can access without tearing anything else back off) so that's on order.

Options for the grinding bearing are it's the new water pump and it was bad out the box (never dropped it or mishandled it) or enough coolant or something ruined one of the other pulleys bearings. Either way, I'm plenty annoyed with the idea of doing the water pump replacement twice, especially after doing the valley pan gasket job twice. Maybe after 20 years of DIYing my own junk, it's time to stop being so cheap and just pay someone else to own these problems.

Going to wash the belt, engine undercarriage/skid plate and transmission tomorrow after work, then reassess the bearing noise and try to determine exactly which pulley it's coming from. Will update this thread and start composing the DIY...though at this point, would you be wise to follow my advice . Going to go enjoy some of my expensive whiskey now, fellas. Till tomorrow.

 

[carlos33018]

you got the job done, that’s all that matters and saved a ton of $$. Waiting for that DIY as I’m sure I’ll be doing this next.

 

[jmanscotch]

you got the job done, that’s all that matters and saved a ton of $$. Waiting for that DIY as I’m sure I’ll be doing this next.

Exactly, I figure the work I did was about $3,500 worth at the dealership and I did it for $500 and a weekend. That said, if the water pump needs done again, I might just take it to them to do for me.

I plan on working up the DIY bit by bit after work this week, so hopefully by the end of the week it’ll be posted.

Jake

 

[Tex68w]

It's a shame that this is becoming a more prevalent issue with these trucks. I am already at 35K miles on my 2019, at this rate odds are this issue will rear it's ugly little head in another three or so years. Hopefully this ends up being a early 460 issue as I have yet to hear of any on the later year model trucks, yet lol.