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Thank you so much for this. You giving me courage to tackle this. Already Have parts sitting in the garage. I also ordered the wire harness.
Just so I don't damage the fuel fitting, is there a trick to disconnect the fuel lines. In the ih8mud , the fuel line was not disconnected. Did you disconnected it so you dont have to deal with the 10 mm holding it to the intake, (such that you removed the intake with fuel crossover still attached).
How would you depressurize the fuel system.
Many Thanks.
yep the service manual says to disconnect the fittings and lift it with the manifold, the problem as mentioned in the ih8mud method is that its unlikely that you will be able to reattach that 10mm bolt to the manifold on reassembly. to disconnect the fitting you first lift up on the orange top of the fitting and it partially unlocks it then youll see 2 yellow squares, one on each side of the fitting, press them in and pull gently, it should come off with little force. immediately cover the fittings to keep any dirt from getting in, this is extremely important.
Follow it to the T, and you'll be alright. Get all the tools he describes as well. The hardest part was the one bolt on the back of the intake manifold and the back passenger side bolt on the intake manifold as well. Other than that, pretty straightforward.
A magnetic pickup tool was a godsend as I was dropping bolts and nuts left and right. I highly recommend getting an endoscope like this:
as it helps you locate the items you'll drop but also all you to see if things have sealed up properly.
I did the entire repair and discovered coolant leaking on my garage floor. After tearing it apart again, I found that I had pinched the o-ring in that tube thing that goes to the coolant plate. The endoscope allowed me to confirm this once I got the manifold off. On the second install, I lubed the o-rings with just a touch of silicone, and they went in perfectly.
Feels good knowing this was done properly and shouldn't leak again anytime soon; that 103 FPIG is some amazing stuff. It was not fun trying to clean that stuff off before the second install attempt.
Good luck to everyone and follow those instructions...they are accurate.
I decided to shelve a kit of parts should this occur on my 460. Just did another coolant change this week with hoses and thermostat also replaced.
I have already replaced PCV but cheap enough to easily replace with intake plenum off to replace.
Nothing to indicate my vehicle has issue but don’t want to deal with ordering parts when or if this occurs in future… that wiring harness for example could be a harder part to find in the future.
This is a list of parts suggested for replacement if or when this issue occurs.
Acrad, good call. You might also consider ordering the housing that the PCV screws into. The whole thing is plastic and with the heat cycles it is subjected to, it's only going to become more brittle with age.
Part number 1221538020 and it's only $16 from PartSouq.
I ordered that part too after your recommendation... I'll take some quick pics before I put the box away of each part for other's reference in the future. Many of them are probably documented here and elsewhere but might speed up someones search in the future. It's always nice to have a pic along with the actual part you are putting in an order for.
Originally Posted by Romanova
Acrad, good call. You might also consider ordering the housing that the PCV screws into. The whole thing is plastic and with the heat cycles it is subjected to, it's only going to become more brittle with age.
Part number 1221538020 and it's only $16 from PartSouq.
Our 2011 with 125K miles on it has the exact same symptoms. We had a local auto parts store diagnose it and it claimed the code was a thermostat problem. Took it to the Lexus dealer the next day, and they said it is a valley plate engine problem and estimated the cost to fix at $3,000.00. The car otherwise is in mint condition. Some say this is a common GX 460 problem. So much for high reliability. Any one else experience this problem.
Do a search on the internet for GX460 valley plate problem. You will find others who have experience this problem including the fluid showing up near the transmission. This is basically an engine sealant failure that occurs around 100K miles. Some have posted a do it yourself fix for those who have auto mechanic skills.
A common problem on the UR series engine. Also common are front cover oil leaks and cam tower oil leaks. Google these terms and you will get lots of hits.
At some point (maybe post 2014?), I believe an improved sealer was used at the factory. I have a 2014 with a small front cover leak.
My 2015 with 110k miles had the valley plate leak...fixed it myself.
It still has the timing chain cover oil leak. I'll fix that next.
I’ve had my timing chain cover gasket fixed at dealership, covered by my extended warranty. Here is parts list from dealership invoice, if you need a reference of what they replaced:
I’ve had my timing chain cover gasket fixed at dealership, covered by my extended warranty. Here is parts list from dealership invoice, if you need a reference of what they replaced:
Timing chain cover gasket repair parts list
Dude, you are a champ! You just saved me a day of hunting down parts. Thanks, brother!
Any chance they fixed these issues in later years? I just bought one and for some reason didn't previously know about the engine valley coolant leak (I had only previusly known about it in the IS).
12-19-22 | 08:56 AM
