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Cleaning Aac Valve

chef_stagea

By chef_stagea,
in Four Door Family & Wagoneers

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chef_stagea Grand Master

chef_stagea

Posted
Posted

hi all im gona clean tha aac valve on my s2 tomorrow

im guessing its just at the back of the intake plenum... i heard theres 2 bits to it??? is this true?

i know i need to pull off the square peice (connected to plenum)

remove electric solenoid

with a flat head remove the jet looking thing...

clean spring and some rod thing

clean with carby cleaner ofcourse...

anything im missing???

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QWK32 Veteran

QWK32

Posted
Posted (edited)

Yes there are two parts two it, there is the solenoid section which is the idle control, and there is the bit with the coolant lines running to it, thats the cold start valve.

Removal:

1st: Remove the larger 30mm pipe that feeds air to the valve from the solid pipe on the coilpack cover. you may need to remove the carbon canister purge solenoid (little blue solenoid just to the left of the "Boost Sensor"

2nd: You need to remove the 3 coolant lines from the AAC, a very small bit of coolant will come out but thats it, no need to block them off.

3rd: Unplug the solenoid valve, light grey plug just above the coilpack cover.

3rd: Undo the 4 M6 bolts (10mm Spanner) that hold the valve to the plenum. Now be careful. If you are you might get away with out damaging the gasket, which means you can re-use it.

Now you will have the valve off. You'll be able to see the two parts to the valve, the solenoid side, which is the main idle control and the bit that really needs cleaning up. and the side that has the coolant lines fed to it, you will see a slitted brass sleeve with spring up the guts off it, this is the cold start side of the valve, once the engine is at temp that slit will be blocked off. You will also see the base idle screw, just make sure its cleaned up too.

To clean, unbolt the solenoid from the assembly, its 2 philips head bolts. when you take the solenoid off be sure not to loose the small spring that sits inside. you should also be able to remove the little plunger part of the valve to clean it up properly. all you can really do with the cold start bit is just make sure the slit isn't gunked up.

once you done cleaning put it all back together. if you accidentally damaged the gasket use a small amount off gasket sealant to help seal it back up, if you use too much sealant it will ooze into the inside of the valve when you do it up, and you don't really want that excess floating around in there.

EDIT: one thing i forgot to mention was, once you've got it all back together. start the engine, then you need to bleed the air out of the coolant lines you removed, this is done by loosening the bolt just near the 3 coolant lines, it usually has a sticker next to it saying something like "Never Open When Hot". i just take the bolt out and run the engine until a steady flow of coolant comes out the hole, then screw it back in and tighten.

i hope thats enough to give you a good idea of the valve, anymore questions just ask.

Edited by QWK32

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