S.A.I. Filter Modification, in VVT engines. To prevent its failure! Alert Alert! (3 Viewers)

[2001LC]

I'm happy to see my replaceable filter MOD adopted, by shops.

The MOD is to make filter easily replaceable. My filter can be replaced in under 3 second, without the use of tools (with engine cover off). Should be replaced: 20K miles or 5 years. Which every comes first

Toyota has made a design mistake, making the S.A.I. pump filter, a non replaceable filter. Their design, should have been easily replaceable filter, in the first place.

Toyota, redesigned the filter. But still, is not a permanent solution. I found two things happen, to old and new:

• They get clogged, increasing vacuum pull on them.
• The filter foam rubber shrinks and disintegrates.

Here's the filter, from a replacement S.A.I. pump. It too, will fail. Notice how the top leading edge has debris. Which has lead to increase vacuum pull along top area, warping top along second chamber. In time it will shrink more and crumble like sand, if not ground in impeller first.
View with borescope

IMHO placing filter directly on the S.A.I. in a 4.7L 2UZ is a bad idea. For a few reasons:

1. The foam of filter will break down in about 5 years more or less, depending on environment it used in. According to, the manufacture of the filter I posted in page #1.
2. The filter will become clogged. Which will reduce air pressure reading at air pressure sensor in main switch. Which will likely, result in "stuck close" DTC.
3. Most importantly. To difficult to replace.

Here's a filter from a 24K miles 07LC. It's foam was like a dried out sand castle. Touch it and it crumbles. It also shrunk.

The small one only had 24K miles, with estimated 400 cold engine starts. larger filter, had ~175K miles on it. Both ~18 years old. Both same factory installed pump & filter, from different climates of use.

Filter, is out of position. Suck into impeller, just starting to be ground up.

TSB form Lexus on the GX460 S.A.I. pump filter recall. Sighted, they thought, moisture made play role in filter failure. I've now evidence they had that right.

 

[DTC72]

@2001LC Your attention to detail, thought/research, write ups, and solutions are great. Thanks for taking the time. I have owned my 2006 LC since January 2007. Maybe 6-7?years ago had to replace both CATs. I live in Las Vegas and most likely the day air has caused the S.A.I. filter to long ago crumble into nothing! At 292k miles I am thinking of replacing the starter (I already have the starter and intake gaskets) as PM so while it is all apart why not do your filter mod. I will take the top of the S.A.I. off to see what has become of the flitsr. Not sure if I should also replace the three switches? Or anything else while in there?

 

[2001LC]

@2001LC Your attention to detail, thought/research, write ups, and solutions are great. Thanks for taking the time. I have owned my 2006 LC since January 2007. Maybe 6-7?years ago had to replace both CATs. I live in Las Vegas and most likely the day air has caused the S.A.I. filter to long ago crumble into nothing! At 292k miles I am thinking of replacing the starter (I already have the starter and intake gaskets) as PM so while it is all apart why not do your filter mod. I will take the top of the S.A.I. off to see what has become of the flitsr. Not sure if I should also replace the three switches? Or anything else while in there?

Replacing main switch, while in there is a tough call. Since to replace later, requires removing the intake manifold (IM) again. The Bk1 & BK2 switches (SW's), can be replaced without removing IM. Do replace any wire housing blocks, that break. Mostly I see, the release clip breaks.

First let me say. I've done dozens of these MODs. Only two, ever had DTC after. Both point to SW's in rear on water bypass (BK1 & BK2)

All 3 switches, pump, VSV and air sensor, can be tested. But the test for air sensor, is voltage. Which will not tell us of issue with clog in sensors air sample port.

I've had two that require switches (SW's), after the MOD. I suspected, dust in air pressure sensor resulted in DTC. But dust can also damage valves within switch.

In the first, filters was gone, and I was getting DTC before. Which I talk about in the beginning of thread.

The second just happen. It's filter was still in cap, but moved out of place. I had no real concern of dust in SW's, since filter still there. So didn't even look at valve stem in main switch, for signs (tarnish) unfilter air. But, I did have the engine out of engine bay on a stand, and rotated to get oil pans off and R&R oil pump. I suspect, as i rotate engine upside down. Dust entered the tiny port of air sensor. We've been, getting DTC Bk1 stuck closed, then DTC changes to BK2. It flipping back and forth randomly. Test systems, before replace main SW. Found a bad S.A.I. VSV, so just replace that, to see result. As suspected DTC still came back. But later stopped getting DTC.. So waiting to here now, if DTC returned. Even though DTC point to BK1 & BK2 SW's. I'll not replace them now. I replace main switch. I could just try replacing air sensor. But if not the issue, or whole issues. I'd then have to pull IM a 3rd time. So it's a test I'd like to do, just R&R air sensor. But not cost effect use of time.

 

[NoTempoLimit]

Number one rule before replacing CAT(s). Find and fix cause, or DTC will likely come back and CAT goes bad again in most cases...

Just did this mod on my 2006 LC with 183k miles, the filter was completely GONE. Not a trace of it remained.
Ozone kills open-cell foam. And Southern California has a lot of ozone. My LC also spent some time in New Mexico. Plenty of O3 there too.

NOTE: When taking the top cover off the air pump, you ONLY have to remove the center Torx screw. I took the outer ones out and then realized that the hold the bottom cover of the pump and drop into the vee. So if you do this you have to pull the entire air pump out to reassemble.

In my defense I was addled by the California sun (I'm in the East Bay Area now, but it can still be quite intense).

 

[2001LC]

When only, adding replaceable filter. I just remove cap from pump, to clean out filter and area in cap.
This is when I'm not removing S.A.I. pump, wires housing blocks, switch (valve), starter or anything that is under intake manifold. To do some other repair.

1. I remove the one torx screw, from center of pumps cap. After blowing dust from area.
2. I heat cap, with hot air gun (hair drier works), 360 degrees around cap seat area. This is to soften, adhesive seal. The caps then, pulls off easily.
3. I remove old filter and clean up any dust or debris, from filter area (cap & body). Then replace cap and screw, making sure adhesive seal, still in good condition and clean.

Tip:
I add just a very little bit Toyota rubber grease, to 1" pipe of cap. And very very, thin layer to inside of 1" hose elbow. Just makes, pushing hose on cap, easier. But we must be very carefully here. To much grease or whatever lube used. May get sucked into primary switch valve. If any gets to tiny orifice of air pressure sensor. We'll, likely get: A DTC after assemble and engine started (usually more than 3 starts). DTC, may change form bk1 to bk2 SW valves stuck closed, or even main SW. Just keep clear DTC (code). See if eventually cleans itself. It may, if your lucky. If not, intake manifold will need removing again. So again, use caution if lubing hose for assembly. Also to remove any and all dust, from cap area.
See post #5

 

[studio19atx]

Has anyone does these on 3UR 5.7?

 

[2001LC]

Has anyone does these on 3UR 5.7?

Likely. Search 200 series section. Also, other Toyota/Lexus forums with 3UR.
In the 200 series, it should be easier. Since it pumps are in front area of front RH fender well. The tricky part, would be to pipe to point that makes filter easily replaceable.