DIY Coolant Valley Leak Repair

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None with small hands at this time.
:)

The more I think about it… not sure I would pre-stage bolt at angle I laid intake down. I’d be concerned it could inadvertently mar something if intake wasn’t laid down perfectly…or even get pushed out.

Interested to hear further experiences of others who choose to DIY this repair.

I’ve got about 60 miles on repair now….. solid so far via borescope views. I plan to drive vehicle as my commuter for a week or so.
 
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Nice job on the fix! Also, please remind me, what's the difficult disconnection step on the rear of the intake again? I seem to remember people discussing this as problematic, as it's a tight fit w/ the firewall being close. Maybe it's a harness connector? Am I being too vague?
 
- Disconnect the fuel lines and you won’t have to deal with the middle bolt removal on rear of intake. It really is easy to disconnect. Just a few dribbles of fuel… just keep something underneath to collect a small amount of fuel.

- Driver side wiring harness connector attached to intake.. look at tips in thread and you should be able to release this with ease… if not…. easy to replace one that gets broken. Part number listed in thread.

- Passenger side wiring harness is attached the same way on that side. Even before beginning work.. just pop the engine cover off and look at how wiring harness is attached to the back of the intake on the driver side. I spent time with my borescope unscrewing the 10mm bolt on the passenger side. Some simply break off the wiring harness connector. It can be unscrewed ..although it will take a long time. There is a post of mine in this thread showing how these clamps operate.

- Passenger side and closest to firewall intake manifold bolt is extremely tight. Look at suggestions in thread on removal. Hex tool with handle made this the easiest for me… just make sure you purchase one appropriate length. I had to bend the one I purchased as it interfered with the plastics housing the wipers.

Local Lexus dealer quoted me $3800-$4200+tax for repair

Hope this helps.
 
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None with small hands at this time.
:)

The more I think about it… not sure I would pre-stage bolt at angle I laid intake down. I’d be concerned it could inadvertently mar something if intake wasn’t laid down perfectly…or even get pushed out.

Interested to hear further experiences of others who choose to DIY this repair.

I’ve got about 60 miles on repair now….. solid so far via borescope views. I plan to drive vehicle as my commuter for a week or so.
Honestly that bolt may have been the s***tiest part of the whole process. I didn’t do any prep for reinstalling the intake - just laid the manifold down and then started working the bolts. I couldn’t remember the socket/extension combo I used to get it out so there was quite a bit of trial and error to get the bolt rethreaded. It’s really the same wrench setup that you needed to get that bolt out.

For seating the oring properly I think someone here mentioned practicing a couple times to get a feel for it before you are ready to seal in the plate. That’s probably the best advice for that step. lube up the oring and then slide the pipe in a couple times to get a feel for how it sets into place. It’s super sexy and fun.😂
 
Hey, all. Dialing an admittedly sellfish lifeline here. I've combed through this post countless times (HUGE thank you for the OG post and comments), I also downloaded as much of the service PDFs from the TIS site as I could in my 2 day subscription, got the tools, OEM parts, etc, thinkng I could do this on my own, but needing an assist here.

I'm stuck on the EGR cooler. Namely the back two torx threaded bolts and 12mm nuts on the EGR output. I got one nut off with a breaker bar, but the lower nut stripped, then the torx head stripped. I used liquid wrench on the bastard but it didn't budge.

Any ideas here on how to break those loose? Or get a stripped nut off in those tight of quarters? My hail-mary here is to remove/reposition the main wiring harness, dremel off the stripped torx end so I can get a 6 point properly square on it in those tight quarters.

Again, sheepish first post here, but appreciate any help or advice. Thanks!

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I don’t remember that one being difficult with a small 1/4 inch wrench on mine.

Was socket a little damaged/rouded?

Small ratcheting 1/4 inch 12mm wrench should get in there as well.

Once that nut is off it will easily slide out of there

Nuts should be the only thing needed to remove. Torx thread bolts will come out with the EGR cooler.
 
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Yea that sucks. Do you have a 12mm line wrench? Maybe gets a better grip on that nut? You can’t really hammer on a smaller socket at that angle.

Otherwise trying to break that nut with a dremel/air hammer something to come squarely at it. Even a flat head screwdriver that you can hit with a hammer land if you can get your torch down there a bit of heat might help-although I don’t see any corrosion…
 
Thanks for the tips. I used a line wrench on it at first, but the tight quarters wouldn’t let me get good leverage.

Next I had a 6 point semi deep socket on it (threaded torx bolt wouldn’t allow for shallow socket / firewall is too close for deep socket) but the tight quarters + breaker bar must’ve goobered it up.

Will check into heat and maybe something like the Gearwrench extractor. Never heard of it but I’m not a grease monkey on the regular, maybe it will work? 😅

Appreciate the input!
 
Update: Was able to get a bolt extractor on it and wrangle that sucker out. Those specialty sockets have earned a spot in my tool box for sure. I have 9 more knuckles to bloody up, too! Things are looking up! Thanks again for the responses and help.

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Another gasket option

Founder of Sucker Punch Motorpsorts told me their gasket works on the 1UR-FE as well


"The SPMS 1UR Valley Cover Gasket is a high-quality automotive gasket designed for sealing and taking place of the Toyota sealant, used from OE. Made from AFM materials, this gasket is specifically designed to fit the valley cover of the Toyota / Lexus 1UR engine. This is to ensure a secure seal and prevent the dreaded valley cover leaks that plague the 1UR."

Screenshot 2026-04-05 at 8.23.32 AM.webp
 
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