Cleaning the IAC Valve for the Saab 900s and N900NG

If you are having problems with your idle air control valve, your car shuts off during idling. Then it might be your IAC (Idle Air Control Valve) for your Saab 900 s NG 900. Go ahead and complete this detailed instruction page.

IAC valve is under the plenum
Picture #1: The IAC valve is under the plenum on the passenger side.  

Cleaning the IAC Valve for the Saab 900s and N900NG
Picture #2: You have to remove this rubber flex pipe first.

Cleaning the IAC Valve for the Saab 900s and N900NG
Picture #3: From the passenger side you can see how to access the clip to remove the plenum.

Cleaning the IAC Valve for the Saab 900s and N900NG
Picture #4: You have to take a long screwdriver to unlatch the clip.

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Picture #5: Here the clip unlatch.  

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Picture #6: Here is the wrist movement you have to do to remove the plenum.

Picture #7: This is the underside of the plenum.

Picture #8: Passenger side anchor point.

Picture #9: Here what’s under the plenum. It is a good idea to place a towel over the trottlebody so no debris or dust can go inside. Note that on the non-turbo model, there’s no clips on the IAC hoses where the turbo model has.

Picture #9a: Geoff (on TSN) pointed to me that the plenum on turbo engine doesn’t have a clip but a small metal post covered with rubber. Here a picture courtesy of Mattias.se (on TSN).

Picture #9b: Here another point of view.

Picture #10: A closeup of the upper end of the IAC

Picture #11: Press on the metal clip and remove it. Then disconnect the plug.  

Picture #12: The IAC valve is held on the engine with a pin that goes in a hole in the rubber part of the IAC. So you have to lift vertically the valve after you have disconnected the two hoses. 

Picture #13: Underneath the IAC, you can see the support hole. Note the difference in size of the inlet and outlet.   

Picture #14: Here that gummy stuff that you have to remove. I’ve cleaned it about 13 month ago, so once a year is not too much.

Picture #14: Put the IAC over a container and spray carburator cleaner generously and get some inside the valve body. Repeat many time. Don’t forget to wear goggles. Also it can damage your car paint.

Picture #15: Insert a clothes or a paper towel inside to clean the inner side of the IAC. Don’t leave lint or paper pieces there.

Picture #16: Use cotton swab to clean the gate. It may help to use at the same time a small screwdriver to turn the gate and clean it all around. (Sorry, not able to take the picture!) Update: Don’t try to force open the gate, il will damage the IAC gate. I managed to clean it in closing the gate as much as I can without forcing anything  

Picture #17: After the cleaning, put some oil in it, don’t be shy on the quantity. I use 0w30 synthetic motor oil, last time I’ve use synt. transmission oil. Update: Don’t let too much oil in the IAC let it drip.

Picture #18: Turn the IAC upside down and let the oil drip. Don’t wipe clean the interior, the oil is there as a lubricant. Don’t worry, it is not harmfull for the IAC. Wipe clean the exterior.

Picture #19: Put back the IAC on his support pin first and slide it down gently. Plug the hoses.

Picture #20: Now this is the time to clean the trottle body (upper part). Put some carburator cleaner and wipe with a rag, try to open the butterfly with your hand and clean the inside. Put some oil at the pivot point. Wipe it clean and leave no lint or residue.

Picture #21: Before putting back the plenum, it is a good idea to look at the o-ring at the trottlebody connection. Also put some kind of grease (vaseline or silicone grease). To put back the plenum, just align the two anchor point and gently push forward and down until the plenum is well seated on the trottle body. It may take a few time to succeed but it is easy.

Picture #22: With your hand, clip down the plenun clip.

Picture #23: Put back the rubber flex pipe and voilà!

2 thoughts on “Cleaning the IAC Valve for the Saab 900s and N900NG

  1. michaelst

    i have a 98 900s turbo and from talking too people this would be very helpful if pics where here alot”” of 98 or the 2.0t owners have problems with this ..dealers and repair shop aswell

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