bloc
SILVER Star
This has been a known thing for some time. Bad metallurgy in the springs results in failure, in a way uncharacteristic of most Toyota products. IIRC there are microscope photography of the material defects floating around.
Death of a 3UR (1 Viewer)
- Thread starter Bryanseye
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xeuxaz
SILVER Star
How common is the failure? 
Idk… maybe. There should be signs of weakening like an increase in top end racket or power issues under load. A spring just yeeting itself has either been crying for help and it’s gone unheard, which is very possible, or something else. I wonder what the CEL code experienced by @fj40z ended up being?
I never had any noticeable top end racket or power issues under load but I haven’t towed anything in several months. Did make a few mountain trips and never noticed any power issues though. I can’t recall exactly what the CEL code was initially when I had the CEL and check VSC system that happened several months ago but in this instance when it happened and the miss was evident it was multiple cylinder misfire code. The misfire counts being the highest on #5 and #6. The mechanic called me late yesterday to give me his initial findings of the broke exhaust valve on #5. He is supposed to check out the other side today and see what’s going on with #6 today.
Interesting that the misfire is in the same cylinder, could be the spring was crying for help.
bloc
SILVER Star
First hit from google.
www.autoblog.com
UPDATED: What's really going on with Toyota's faulty valve springs [w/ video]
Failed Lexus IS350 valve spring – Click above for high-res image gallery
www.autoblog.com
Can see that write up was in 2010.
Moby
GOLD Star
Are there any superseding part numbers for the springs which might give an indication of this was fixed in later years?
sleepycruiser
I will get by….I will survive -Touch of Grey LC200
How much does it cost to replace the springs preventatively?
Started with toyodiy.com for top end parts.
Then I go to toyotapartsdeal.com. They show the superseded numbers when you do a part look up.
Then I go to toyotapartsdeal.com. They show the superseded numbers when you do a part look up.
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I don't think this warrants a knee jerk reaction as a systemic issue worth chasing for preemptive fix. The fix itself could introduce issues due to labor skill, parts, etc. Anything mechanical can ultimately fail and valve springs breaking are not a new thing. Across all manufactures. The 200-series has been out long enough to anecdotally say that this is a pretty rare failure.
Worth a discussion though. In the late 2000 model years, there was a recall from Toyota for most of the Lexus passenger car lineup including IS, GS, LS about valve springs and inclusions in manufacturing causing failures. As it effects multiple engine architectures, it probably was a supplier issue in Japan. That is where our engines come from I believe.
My personal takeaway is if there's anything suspicious in running, idling, noise, or CEL, it's worth looking into rather than ignoring.
Worth a discussion though. In the late 2000 model years, there was a recall from Toyota for most of the Lexus passenger car lineup including IS, GS, LS about valve springs and inclusions in manufacturing causing failures. As it effects multiple engine architectures, it probably was a supplier issue in Japan. That is where our engines come from I believe.
My personal takeaway is if there's anything suspicious in running, idling, noise, or CEL, it's worth looking into rather than ignoring.
Thanks for posting this, it appears that they switched springs for the 2018+, I’m relieved to read that. Hopefully, this makes an extremely rare failure even less likely.
@TeCKis300 how many miles are on your LX? I was debating on replacing all my valve springs.
Valve spring replacement is a huge job that typically requires the heads being removed
When we were replacing valve springs on LS460s when their campaign was out, we had a special tool to air up the cylinders so we were able to replace the springs without fear of a valve dropping. It could definitely be done on the 3UR!
Upgrade time anyone?
XAT racing 3UR valve springs and titanium retainers
When we were replacing valve springs on LS460s when their campaign was out, we had a special tool to air up the cylinders so we were able to replace the springs without fear of a valve dropping. It could definitely be done on the 3UR!
Upgrade time anyone?
XAT racing 3UR valve springs and titanium retainers
About 150k and going strong. It's a Toyota and I don't need to overthink it. Just follow the maintenance schedule and beat on it.
bloc
SILVER Star
If I were to mess with this, it would likely be along with timing chains and tensioners, possibly phasers, and a re-seal of my leaking chain cover. With all of that out the cams aren't a big step, but as you mention there are absolutely ways to replace valve springs without pulling the head. Air pressure is one, feeding thin rope into the cylinder via spark plug hole then turning the crank to push it all up against the valves is another. One of those would be my strategy.. the heads can stay in place given our head gaskets being generally problem free.
- Thread starter
- #117
@fj40z got his spring today but I will let him share. It did remind me that I wanted to post some detail images of mine. Best I can do with a cell phone.
By the way, I am waiting on a warranty replacement for my swap since we have a couple issues with it that popped up during a 500 mile inspection.
By the way, I am waiting on a warranty replacement for my swap since we have a couple issues with it that popped up during a 500 mile inspection.
Replacement as in a 3rd engine?
Man, if that website doesn’t get my meager little mind racing in directions my bank account cannot condone
I thought it was neat that they have all those high end components and they sell the OEM chain to keep them in time.Man, if that website doesn’t get my meager little mind racing in directions my bank account cannot condone
But yeah, you’re dropping 5 digits easy if you do a full on build.
