FrankT

Good going!
...and thanks for sharing. I'm wondering how the ACIS valve broke, never heard of this happen.

entryspeed

iTrader: (3)

gratz again on the find and being the luckest man out there right now that the engine isnt all chewed up.

az-dave

Not sure, I have 250K+ miles on the car. The brass ACIS valve looks like it fatigued along the shaft it was screwed to.

Hattip FrankT for knowing what that valve is called, :-)

Like I said, this is a 1 in a million....but considering the bank probs, billing probs, and every other "1:100000" thing lately its of no surprise to me.

The crazy thing is it coincided with the failure of the OCV valve solenoid, so I was getting compounded symptoms, which was making my diagnosis a nightmare.

4-1/2 days, running perfect. ~~~ :-)

az-dave

Interesting. Looks like the valve is supposed to be in the "Open" position normally, and only closes under 60%+ throttle or over 3900 RMP.

http://en.wikipedia.org/wiki/Acousti...duction_System

I dont have mine anymore, so I guess I can beta test how the engine performs without it closing at WOT...so far, I feel no difference...I think its mostly a noise thing, and I have CAI, so its loud anyways.

mex lex

iTrader: (4)

Glad to hear that your car is running good az-dave. I know that you have countless threads and posts about the problems with your GS.

That is very weird about the valve breaking. Mine was removed. It is common to remove it for NA-T applications.

az-dave

I dont have too many threads about probs with my GS, Ive just taken the time to well-document the few probs Ive had.

My GS has a tad over 250,000 miles on it, and I drive her pretty hard, so some probs are to be expected. Many of the issues, such as the thumping sound, were mis-diagnosis from Lexus dealers, and just took a long time to finally identify.

The Probs Ive had with my GS:
1) Master Cylinder Nitrogen Booster Failure - This one was scary, and 3 Lexus Dealers couldnt identify the screeching sound nor why the brake light was illuminated. I ended up replacing myself.

2) Power Steering Hose Pin-Hole Failure, not due to rubbing or contacting hot, just a pin-hole in the original hose.

3) Throttle Body Idle-Control Motor failure. Again, Lexus dealers were incapable of narrowing down the actual part, and insisted on replacing the TPS sensor. I bought a used TB to avoid the $1800 lexus thought was necessary.

4) Replaced Transmission at 225K miles due to Thumping Sound - Prior to narrowing it down to the Tranny, which I thought was the source of the sound all along, I replaced the front wheel bearings, rear wheel bearings, re-did the rear-end, and rear CV Joint seals, drive-shaft center bearing (a PIA to get to) After replacing all those parts, I deduced it was from the tranny.

5) ACIS Valve failure leading to bent spark plug leading to misfire.

There may have been a few minor other probs, but Ive had the car for almost 10 yrs, and put 220K miles on it....to be honest, I couldnt be much happier with the engineering and reliability...the only issue is, when a problem does happen, it seems to be a weird difficult problem to diagnose, even for the pro's at the dealers...

thanks!

az-dave

Quick Update: Driving car all last week. No probs. Way more power than before, which should be expected. I found a small vacuum leak near the ACIS valve, took are of that, seems to idle even a bit nicer. Cant complain for 250K miles.

Ive put about 150 miles on it since the repair.

mex lex

iTrader: (4)

Well I'm glad that your GS is now running trouble free! By the way, maybe this means you can bring her out to one of the local meets if you are in the PHX metro area. Check the southwest section for more info!

See the last past for info on the Wed Night Meets

https://www.clublexus.com/forums/sou...thread-39.html

az-dave

My next project is the Turbo. I have all the parts, but I wasnt driving the car much the past year due to the poor running...I may come to an event, but my car has been around the block a few times :-) LOL its not trashed, but its got its age-marks per se.

az-dave

This is Off-Topic, but this is my thread :-)
Im going to open a new thread in a while concerning Synthetic Oil and such...Im sure its going to throw some people for a loop, and will generate a lot of controversy. I waited to start it until I fixed this last problem, which was due to a broken ACIS valve that has nothing to do with Oil.

Lets just say I know some people will tell me Im full of it, but Im hoping to hear feedback from some other people that have similar experiences...

Gimme a few days.

az-dave

Update:
Still running good. I do have an intermittent code thats throwing the CEL, Bank-1 too lean.
I think its either a fuel injector starting to go bad, or possibly something to do with the evap emissions loop. OCV and VVTi are running fine.
My other thread I promised is here, its generated quite a bit of controversy, as I suspected: https://www.clublexus.com/forums/per...-interval.html

Suprags300

try cleaning the mass air flow sensor. Fixed my car issue quickly

lx4rdh

Hello Suprags
Was your car doing all the az-daze car? If not what was yours doing

az-dave

Update on the P0171 Lean Code. I finally tracked it down to 2 small vacuum leaks. One was the PVC hose on the CAI intake pipe. It was clamped but the hose was kinked and allowing some air in, after the MAS sensor. The second leak was a cracked vacuum hose on the back of the intake manifold Evaporative system. That hose is a special one, so I siliconed it up and clamped it up and its fine. No codes now for 1+ week.

az-dave

Justa quick update:

March 23 2012. Car still running great. More than a year after finding and fixing the ACIS valve issue. 253290 Miles.

No Codes. No misfires. (and No ACIS valve haha)

This car just keeps going and going. Ive taken it to Vegas and Rocky Point since the repair. Now that takes guts! :-)