328 auxillary air valve

Hi,


Check the electrical resistance of the heating element in the valve, and if you get power on the connector when you start the engine.
You can also connect the valve to the battery with two wires and check if the valve moves after few a few minutes

 

I recently replaced the AAV in my 308 QV for similar reasons. My cold idle was steadiy decreasing over a period of months until it was down around 500 rpm. My AAV when removed from the freezer was only about 15% open. I ordered a replacement from
Rock Auto and that did the trick. It was about 35% open when in the freezer if that helps.
Not sure about the 328's AAV positions. Generally though it

 

Mine is more open than the one pictured from the freezer & it closes completely in the oven.

 

No, I don't think that that's a requirement/goal of the design. It is important that it is fully closed when warm so yours seems NG (and, if your car was warm idling well with the AAV stuck open, you'll probably need to do some tweaking when you correct the situation).

They aren't as complicated/expensive as a FD or WUR -- just try searching using the 10 digit Bosch PN at www.importeccatalog.com, www.rockauto.com, www.autohausaz.com, www.pelicanparts.com, etc..

 

My bad for trivializing finding one -- I'm now recalling that the 328/3.2 Mondial AAV 0280140229 was expensive unobtanium a few years ago.

Can you post a picture of how your AAV mounts? Is it a super odd-ball thing to help transfer the coolant tank heat into the body of the AAV?

 

Dan,

If you get into a jam finding one (as in - you CANT find one), let me know, as Ive made a home made one for an L-Jet Bosch fuel injection system (not sure if thats what you have), out of a water heater valve and bicycle cable (I dont have a 328, though, but Bosch L jet is the same, I believe). Yes, its "manual", meaning you will have to "choke" the cold engine on every start, but big deal, right? Thats what all of us did before automatic chokes years ago.

Mine woorks every time, period, and no depending on resistivity/etc to operate it.

 

Any time, Bro!

 

Thanks for the pics. Not sure that this makes it any easier, but I noted that some of the Porsche 911, 924, 928 of the same era seem to use the same body style AAV -- even if the Bosch PN isn't exactly the same, I can't imagine that they'd be hugely different in function:

http://www.ebay.com/itm/Porsche-Auxiliary-Air-Valve-Regulator-0280140218-?cmd=ViewItem&item=160593024103&vxp=mtr

 

Contacting Bosch? This is like contacting the CIA, if you don't know someone or the structure of the Co. you will first get the runaround and then a load of BS and if you are lucky they will give you to tech support where they will give you my phone number. I will be talking to the head of the dept. that is in charge of older car parts on monday the 7th. This is at the HQ in Karlsruhe, Germany. I will find out what is a good replacement or if they will make a run of these for us.

Larry Fletcher
www.cisflowtech.com
251-929-3771

 

Anyone opened one of these up by drilling out the rivets? Maybe just needs a cleanout inside?

 

Im sure someone here has and l seem to recall seeing pics as well.

 

AFAIK its just a bimetalic strip in there so either its clogged up as you suggest or its just got fatigued & broken. My bet would be the latter on this one but no harm squirting a load of WD40 in there to see if anything comes out. I did that with mine when I took it off & its suffered no ill effects from it.

ISTR the other test is to connect a meter on the electrical connection & make sure that there is a circuit there - if its open circuit then ISTR Rifledriver saying it was toast & wouldn't work properly. I guess there must be some kind of heater element in there maybe?

 

Larry, see if they will do a run on WURs too. It was posted here that German law requires parts be supported for 30 years, might ask them about this?

 

It is a simple bimetallic strip so it closes to lower engine speed as it gets warm. That;s why these are typically mounted somewhere where they get warm and have a big mounting bracket for a good heat transfer. You'll find them mounted to the block or head or water tank depending on the car. There is a small heater to warm the bimetallic strip so that they close with running even in very cold weather, etc.

This device's part number may be special to your car, but he AAV is not. There are 10 million+ AAVs out there and they are all remarkably similar. The only real differences are tube diameter and mounting foot. If I couldn't find exactly the right part number I'd grab one off of a Porsche, Jaguar, Mercedes, Volkswagen, etc and hook it up. I'd do that before making a cable operated version.

 

Yes, I bench tested mine a while ago and it goes from completely open to completely closed with 12 volts applied in a couple of minutes.

 

FWIW, as far as Ive been told in years past, theres no way to "repair" a L jet (or other "jet") AAV's bi metallic strip. You have to throw it out/make a new one/get a new one.

 

If it does not perform with the "freezer" test, its no good.

 

I don't think there is any black magic with bi-metallic strips they can be found in lots of devices. I think the problem with restoring may be with the heating elemants. IMHO.