sivert55

I had this problem over the weekend on '12 gx 460 with 85k miles.
Found the parts myself online for $350. Took out the bad ones in 30 minutes. Then i came accross this thread.
Called Lexus Monday morning, they agreed it's an extended support item with coverage to 10yrs after vehicle purchase date or 150k miles. I sent the parts back and took it to the dealership.

My local Toyota service manager says he sees this problem every so often on any Toyota V8 from 07 forward.
I called Toyota to see if my 08 sequoia was also covered. Yes, it is, although they won't make any repairs proactively. The vehicle must exhibit the prescribed symptoms first. Then they have to verify it at a dealership.

sivert55

Curiously, the filter was completely intact and still pliable. The fan blades were in pristine condition. But there was a lot of moisture in there, probably because of the Florida weather. Heat metal up and then let it cool, it will collect condensation in high humidity environments. Dealership called today and said the fan seemed ok but they were replacing it due to the "circuit" error code. He also said that's just the normal procedure when they have this problem on any Toyota V8s: replace all 3 parts.

Also curious: the Toyota dealership quoted me $1100 for the whole service with parts. I triple-checked that he was doing the whole job. That's far lower than the $3800 i've seen others pay in this thread. He said the placement of the components in the engine bay of the gx 460 just makes it all take less time to do. Perhaps parts prices have fallen too?

bbqsoup

Sivert55, so are you having the GX fixed at Toyota dealer or at Lexus? I'm surprised at the difference in price. Wow!

Acrad

That is a huge difference in price between the Lexus and Toyota dealer. If mine goes bad I'll have it done at a Lexus dealer assuming it is still within the warranty period since that is more convenient.

tecman

So the filter is intact but yet there is gunk, gaskets failing? So happy to to just shut this poor system down with a lifetime warranty bypass. If the bypass fails I can go back to this system until I get a bypass replacement.

Did you notice any gaskets in place or missing when you removed this sirvert55? What else could this be?

Acrad

Yeah... look at those pieces that look like gasket material. I wonder where that came from? That got infused with some material along the way. That is a bizarre one if the foam is still intact.

Acrad

Almost like the gasket on the air valve face got sucked in when valve got stuck closed.

HotKoolaid

Does anyone know what they used for the filter medium? My pumps and valves were replaced in 2015 at 55k miles. Just shy of 88k miles now. Pulled the pump cover and the filter was in perfect shape as was the fan. Curiosity got the best of me and I pulled the drivers side valve. Full of dirt. I cleaned it up and pulled the hose, which was also full of dirt. I'm guessing it's not the filter material that's failing but the filter is not doing a good job of keeping out fine particles. Passenger side valve was not as bad but the hose was dirty.

I bought an external breather style filter, but I think I prefer an oiled foam filter. I rubbed a little grease on the inside of the pump cover that should collect any dirt. I'll run it for a few weeks and see how it looks. If it's bad I'll switch to the uni filter and retest.

Acrad

Seems to be a lot of potential failure points with this air injection system.

bbqsoup

No kidding...it looks like this thing can fail at any given moment LOL. I just sprayed a very light coat K&N oil on the Uni filter hoping to catch any fine dust that may passthrough the element. A friend saw my filter and asked me to get one for his Tundra too.

Jtolan

I started my car and the check engine light and slip indicator light came on and stayed on with the 4LO blinking. Now the car seems to be in Limp Mode. Not sure if I should have the car towed to the mechanic or safe to drive it is about 40 miles.

Acrad

Most likely this

https://www.clublexus.com/forums/gx-...50k-miles.html

Dallasguy1

Tow it to the nearest dealer it's the secondary air pump system, been discussed many times, it's covered under extended warranty if u have less then 150k miles.

sivert55

The gaskets that seal the valve to the valve body were intact. Those are the pictures further up this page with 2 or 3 rectangular holes in them. You can see the gaskets are still sealing, though one of them was impacted by the moisture.
-Sivert55

sivert55

Yes, the rubber got water-logged and ballooned up. There were more circular gasket edge pieces in there that I pulle doff before i took the picture.
Yes, the filter material in the air pump was completely intact and remarkably clean.

As I said, i had the service done at a Toyota dealership by a technician who had done this exact same work on Toyota V8s. He said he sees gaskets looking like that all the time. He suspects it's due to the condensation that gathers in those aluminum valve bodies every time the vehicle cools down and sits in the humid air outside overnight, with no way for the condensed water to get out, no drain. The valves are identical between Lexus and Toyota 4.6 and 5.7 V8s. The fans, I think, were twinned in some later 5.7L V8s to provide more air volume, though. So the air pump part was specific to my 4.6 in this case.