Step By Step Instructions For Iacv(idle Air Control Valve)/isc/throttl

[gau]

FYI, the brass washer go into the hole where the stud is... see image

[code58]

I did discover that right after I posted. Great instructions!!!

Some observations after doing this yesterday:

A #3 Phillips and a firm grip loosened the throttle body screws just fine. The "wavy washer" fell out and was not discovered until the car had been reassembled. I do notice the idle is now double the 700 rpm listed as normal. And, I also have noticed that others have had higher idle after doing this procedure but no one seems to have offered a solution!

The wavy washer is brass, so if it falls somewhere, a magnet will not retrieve it. And, if I decide to reinstall it, where exactly does it go? Over the magnetized piece on the end of the sensor? BTW, that's why the washer is brass... so the magnetism will not affect it. And, I did something you really should not do but has seemed to work. The oddly-shaped gasket that goes between the ISC valve and the throttle body expanded and would not fit back in its groove, so I carefully cut small pieces out of the longer ends (three cuts, IIRC) and managed to get a tight fit when everything was bolted back together. I'm not too happy with this, but so far, so good. Notice that the new gasket is less than $5, so I may get one just in case.

So, any further thoughts on the elevated idle speed??

HYP- The wavy washer on my DIL's RX definitely wasn't brass, it was steel. You wouldn't have to worry about magnetism, that washer isn't going anywhere. Also, did the gasket come in contact with ANY kind of oil or solvent or gasoline. That will swell rubber in a heartbeat, but you can usually shrink it back to normal size by CAREFULLY drying it out with a heat gun or leaving it in the sun, if it's a sunny day. When I did my DIL's, there was no problem with the gasket swelling at all and it went back in perfectly. It's made out of some really good stuff (neoprene?) and looked in perfect shape at 100k mi and at 150K mi and 13 years (early build) it has never leaked a drop. And your current idle speed is perfect!

[Hadyourphil]

Interesting. Mine is brass colored and is not magnetic, so that rules out steel. And, as magnetism plays a role in how the air valve works, it makes sense to me that the washer would not be made out of anything magnetic.

As far as the gasket goes, I think I will replace it since I did have to cut mine to fit it back and I do not want to leave it that way. Since I'm going to replace the spark plugs fairly soon, I'll replace it then. Wish I had tried the heat idea, but I didn't know about it.

You guys are great.

[1965keating]

Excellent directions. Needed vice grips on several screws but my car is 12 years old. My valves were considerably dirtier than the picture you provided. I hope this is my answer. Thanks for saving me about $200.

[yvenu]

I couldn't remove the third fard end of the throttle body screw. It's very tight. My philips scree driver tore the screw grove. There isn't enough space there to use locking grip pliers. Any ideas? help please!!!

[lenore]

take a broken hacksaw blade (real short) and saw a flat into the screw, then used a regular screwdriver. Dremel tool would work for this also...

[ctumbler]

Wondering if someone can help out with this....

Girlfriends 2001 rx300 - car was not stating, low idle, etc etc

Performed the short cut procedure last night, and the car fired right up, awesome. Went for a test ride for the computer to reset and when I returned to the house the car was idling crazy - surging from 1000 to 2500 rpm but driving fine, thought it might be a vacuum issue, but the surging threw me for a loop. I removed the air filter and went through the procedure again to no avail. I read the entire thread and found only one note that might relate to this issue, stating that the valve had been re-installed incorrectly. I have gone back through the steps, and everything looks correct, so I am a bit stumped since I didn't remove the valve, any thoughts?

Thanks

[ctumbler]

Just cleaned my IAC valve, my RX is running again. It helps to loosen the screws with vise grip first. I did not install the valve correctly the first time. The car will RPM will go up and down.

I took valve out and reinstall it correctly and making sure both valves opens at the same time.

Thank you very much to all !!!

Can you describe the issue you had with the re-installation? I am having the same issue on my end, but I didn't remove the valve body, I did the short cut fix.

Thanks

[ctumbler]

Replaced the entire unit and all issues have been resolved - thanks for the step by step!

[MistahX]

Thank you "Golden" I just did the step-by-step and it took me 1 hr. The truck started right up and is running beautifully. One thing though, once I started the truck, the TRACTION OFF light came on along with the VCS and the CHECK ENGINE LIGHT. Did this happen to anyone else?

[rodney79]

This is a great write-up. Local shop quoted me $895.00 to replace the IACV. With my son's help, we removed and cleaned the IACV in about two hours. The hardest part was breaking some of the screws loose. I found that if I attached vise grips to the screw head and tapped with a hammer a couple of times, they broke free much easier. Thanks for the help!

[sc_owner]

To GoldenStateSilverSport

Thanks for the detailed (w/pics) instructions on IACV clean out. Just completed, worked great. Solved my prob and saved me several hundred bucks I'm sure. Note to users of these instructions, it is possible to put the Black Electric Coil in upside down be careful there. Caused my engine to idle rapidly oscilating up and down between 2000-2900 rpm.

[sc_owner]

Just cleaned my IAC valve, my RX is running again. It helps to loosen the screws with vise grip first. I did not install the valve correctly the first time. The car will RPM will go up and down.

I took valve out and reinstall it correctly and making sure both valves opens at the same time.

Thank you very much to all !!!

Can you describe the issue you had with the re-installation? I am having the same issue on my end, but I didn't remove the valve body, I did the short cut fix.

Thanks

I had the same oscilating issue. I had put the Black Coil upside down. See my post under SC_owner.

[sc_owner]

To GoldenStateSilverSport

Thanks for the detailed (w/pics) instructions on IACV clean out. Just completed, worked great. Solved my prob and saved me several hundred bucks I'm sure. Note to users of these instructions, it is possible to put the Black Electric Coil on upside down be careful there. Caused my engine to idle rapidly oscilating up and down between 2000-2900 rpm.

Noted that many were having issues with screws, etc. The advice to tap the screw head thru a screwdriver was essential for me. My screws were not budging even with visegrips and high torque screwdriver combined until I tapped them. However I did add one drop of xxblaster for my final try. I literally snapped 2 screwdriver heads (insert type - potmetal?) trying to remove them. Instead of a steady pull on the visegrips give it a snap (old sailing trick). The visegrips also were great advice. Thanks for all the helpful tips on this site. Couldn't have done it without you.

[jayfoe]

dealership says i need a throttle body cleaning service and they want like $200+ to do it. i declined it. now is this DIY for the throttle body cleaning? if so, just reading over the directions it seems simple enough. would i be right in saying that the difficulty level is pretty low and i could do this myself? this process doesnt seem worth $200 and like i could do it myself.

[joujeh]

Dealer advised that the Throttle body clean up is needed on my Lexus 00 RX300 and for $69. Car has no CELs or no issues. Should I still do it with 125K miles on it? will they take the whole thing off and do a thorough clean for $69 or just a quick cleaning? Sounds like a quick cleaning from reading all the posts here.

[michaelamiller]

yup there is.. for those new to this, theres a total of 3 gaskets on my 2001 es300,

a paper-think gasket between the throttle body and air intake valve

a small round o-ring gasket between the coolant recess hole on the throttle body and air intake valve

the gasket between the iacv and the throttle body

these were not on stock at the dealer, so had to order takes 2 days

while ur ordering, you can also order new screws, 2 for the iacv, 4 for the iavc/throttle body, and 3 for the throttle body/air intake valve (1 short, 2 long)

[michaelamiller]

This is one of the best posts I've ever seen. The instructions are clear and concise. The pictures are excellent and detailed. I was easily able to follow the directions and everything worked exactly as described. I'm not a mechanic and have just a little skill at auto repairs and would normally never attempt this kind of repair so this says a lot. I needed every toll described and encounter each difficulty; but was able to proceed based on the detailed instructions. Thanks!

[mkmroz]

I just bought a 2000 RX300. I am going through this problem. I got as far as I could and could not remove the throttle body. With any force to screws they started to strip and I can't even get a 5" vice grip in there to turn it. Two places want me replace the whole trottle assembly for $750.00. Any ideas??

[RXToro]

I found the following shop manual on IACV testing and installation.

Hi! I came across a PDF you uploaded with great step by step instructions and photos! Would you share where you got such manual? if there are other similar ones? I am looking for a good diagram with explanations of the "underbelly" of my RX and what's where there. For example, this weekend I got a problem that may or may not be related to a disconnected pipe i see by just looking under the car. I want to figure out what that pipe / tube is for.

thank you in advance :)

[dennispec]

Thank you so much for this post, especially the pics!! I am a COMPLETE novice when it comes to car repairs, but I also happen to be completely broke at the moment. So, when my 99 RX300 started not just idling roughly, but stalling almost every time we started it I of course panicked and started counting to coins in the jar on my dresser! :cries:

Thanks to your post and a $4 can of valve cleaner my 12+ year old beauty is running better than it has in years! I can't thank you enough!

For those of you who are contemplating doing this job yourself and have any doubts... trust me! If I can do it, most anyone can using this information and pictures! Go for it!

[french fry]

Thank you so much!! My Wife and I just moved and both of of our cars are having problems, we cleaned the ICV in my 01 Lex and it runs like a champ! thank you so much!! :)

[hmp]

The procedure works great and my car starts up fine. Thanks. However, I am now getting "check engine" light code P0120. It is Throttle/peddle position sensor fault. I have a code reader and erased it twice now. Checked everything except taking it apart. I was very careful not to spray the cleaner on the sensor. Anyone have any ideas. Thanks.

[Gestapamabol]

GREAT DIRECTIONS!!! I did the whole thing in about 1.5 hours and my car is idling great!! THANK YOU!!!!

[karthik]

New member and first time poster. I am in the same boat here--1999 ES300 starts and then stops right away unless I press the gas pedal. I have read every post on this topic on the pages here. I have printed the directions and pictures from GSSS who I think has done a tremendous job of helping thousands and I want to be part of that list. I have completed the five steps enumerated by GSSS. I am stuck at the Step 6 where I cannot get the 4 Philips screws attached to the IACV. I even went to Sears to get the bolt out remover and the screw remover (suggested by the poster, TallGuy.) Still no luck. I am so close yet so far. I have also tried the shortcut suggested by poster, Geoff1, on page 2, to use the carb cleaner to clean the protruding rotating magnetic shaft. The shaft was not turning before but now after following Geoff1's recommendation, the shaft now turns but the "starting" condition has not changed. So I took out all the parts again and I am stuck at not being able to remove the 4 screws. What a nightmare!!!! Any other suggestion for me?

Thanks.