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Ended up stripping IAC valve screws (despite using JIS #2) - what are my options now?

7K views 38 replies 10 participants last post by  recalled 
#1 ·
I'd like to open up the IAC valve and clean it - my car experiences an occasional surge in idle RPMs. The screws are completely stripped.

I looked up a few options - am not a fan of dremel method (because the screws are fairly flush with IAC valve cover) or using drill bits (because I have no idea how deep the screw is, and I don't want to end up drilling too deep). The screws are too threaded for the rubber band method to work.

Any suggestions?
 
#6 ·
No need to take it out. (If it's 5sfe) under the throttle body there is a vacuum hose, behind the connector. Pull it out, take off the intake hose, take some TB cleaner, start the engine, and with one hand hold the throttle arround 2000 rpm and spray inside the IAC hole, not continuosly, spray in short intervals. As you feel the engine choking, slowly raise rpm to maintain constant engine speed. Doesn't need to much TB cleaner. As you see it dripping from the hose you unplugged, when it starts to come out clean, that is it. The IAC valve is a magnetic (solenoid) pin, so that should do the job. No need to open it.
Hope this helps. Don't worry for the smoke from the exhaust, it is normal.
Cheers

Sent from my SM-J530F using Tapatalk
 
#16 ·
If you are willing to replace the old fasteners, you can use a Vise-Grip (or similar) pliers on them. Tighten really, really fully, onto the head and twist them out. As for replacement fasteners, I too like to use hex socket screws in tough spots because they aren't as likely to strip and you don't need as much clearance with them. I also recommend actual JIS fasteners if you use hex cap screws (I usually buy the correct Toyota fastener - Toyota's prices for these fasteners are not out of line with buying from a quality hardware store). I absolutely hate it when I go to remove a fastener and it has an ISO/DIN sized head.
 
#17 ·
I also recommend actual JIS fasteners if you use hex cap screws (I usually buy the correct Toyota fastener - Toyota's prices for these fasteners are not out of line with buying from a quality hardware store). I absolutely hate it when I go to remove a fastener and it has an ISO/DIN sized head.
I agree. Belmetric has a great selection of JIS hardware if anyone needs to stock up.
 
#19 ·
I hope you have better luck, but I've never had any type of screw extractor work. Ever.

Last resort: Use a dremel with a cut-off disk to saw the head off. Use the kind of disks that have fiberglass reinforcement.
 
#20 ·
fingers crossed.

if i go the dremel route, i would need a very small spinning saw to avoid damage the iac valve body cover itself, correct? most demos of a dremel on youtube are on screws that are half-way into a piece of wood, which i would think is much easier to deal with than a screw that's flush against a part that you don't want to damage.
 
#28 ·
I've drilled the screws with success. And it's not real hard. Good drill bit, and the phillips head giudes the drill. Once the cover is free, the body of the screw is proud of the surface, and can easily be withdrawn, sometimes by hand. Always by plier.

BTW, you'll know when the screw has been drilled enough, as the head will spin free.
 
#30 ·
Thank you for the photo. If those came from a similar IAC, then there should be little trouble slotting the head(s) of any stuck screw. Just don't slot down to the bottom, because the two halves of the now-slotted screw can surely twist right off. Does anyone also have a snap of this particular IAC?
 
#32 ·
Excellent information - thank you.
Based on those illustrations at Rock Auto, there appear to be four (4) mounting screws. They all appear to be accessible for slotting, and without knowing what else is in the immediate area, I don't see why you can't use a small vise-grip on the screw heads.
Also, in the past I have used two people on difficult-to-remove cross-recess screws; One to press and hold the screwdriver into the head of the screw, and the other turns a vise-grip clamped onto the shaft of the screwdriver (this will probably chew up your screwdriver, so be warned). Clearly that won't be the case now that there is damage to the screw(s), but it may be helpful in the future if you have a chance to try it before the screws are too damaged.
 
#34 ·
I should have posted a picture a while ago! Here it is. The two screws in question are marked with a red box. Just took the picture in my office parking lot - when attempting to remove, I ofc removed the intake hose/air filter cover/resonator box assembly.

 
#35 · (Edited)
What engine is that? V6? Go to Rock Auto and look up your IAC. I don't believe those two screws will remove the IAC, just partially disassemble it. It looks similar to the IAC on my 3VZ-FE but it's been at least a dozen years since I had to deal with it and I just don't remember. Now I understand your comments about the Dremel. No way on those two but they are not going to remove the IAC. You'll have a better idea after you see the picture of the whole IAC valve. I wrongly assumed you were asking about the 4 cylinder.
 
#37 ·
It's a 4-cyl (5SFE). My mistake if I was incorrectly referring to this piece as the IAC.

They remove the windings for the stepper motor that controls the valve. To remove the valve itself you have to remove the screws on the body itself, which are behind and beneath the plastic part in that photo, on the bottom of the throttle body, if we say that the part pictured here is on the front.
My goal is to get to the cylindrical magnet (as shown in this video) - I want to make sure it can rotate freely. It sounds like it might be easier at this point to take off the entire IAC valve (as opposed to the stepper motor, which I've been incorrectly referring to as the IAC in my earlier posts)?
 
#36 ·
They remove the windings for the stepper motor that controls the valve. To remove the valve itself you have to remove the screws on the body itself, which are behind and beneath the plastic part in that photo, on the bottom of the throttle body, if we say that the part pictured here is on the front.
 
#39 ·
I do see how you mean that the screw heads are flush to the top of the housing. But I also believe that these are the screws that mount the valve to the body, not to mount the body to the engine. If you remove the valve body, you could more easily remove these other screws. Not that removing the valve body will be easy, though...
 
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