Secondary Air Adventure!

[CapnDenny1]

I finally put a good air pump on there, and duct taped the hose from the pump to the combi-valve. It ran CEL free for about 3 days, and luckily I got it to pass the emissions test on that last day it was working. So I finally got the license plates renewed and I can quit worrying about the cops. (It brought back bad memories of my drug abuse days, many, many years ago.)

But now the CEL is back on again. I can hear the pump running and I can hear a loud rumbling sound coming from the engine when the combi-valve opens. I heard that with no pump hooked up, but I assumed that once I put the pump on there I wouldn't hear it anymore. But I do hear it. It does it for exactly the same amount of time that the pump runs. It sounds like the combi-valve is leaking the exhaust into the air duct?

Is this a symptom of a bad combi-valve? Has anybody else heard this rumbling sound when the air pump runs? If I rev it a little it gets quieter, but then as the rpms drop back to idle it gets louder again?

I would just buy one to find out, but they are $250 each, so it's a little pricey to experiment.

Thanks.

Dennis

[Smileybug]

What code is coming up for the CEL?

[CapnDenny1]

It's the same code, Secondary Air Incorrect Airflow. I just thought perhaps someone else has heard this noise when chasing the airflow code.

[billymade]

I ended up having to replace mine; there arn't any aftermarket ones.. .only the German Pierburg company that makes the whole system. It seems we are at their mercy; I did extensive research to try to find a aftermarket version; Pierburg is it, afaik... I did the swap a couple of years ago. As you are experiencing; I also replaced some of the hoses that were brittle and it fixed the problem... they are cheaper in the UK/Germany but I couldn't find a source to ship it over; apparently they are used on the VR6 Eurovan as well... go figure! The Jetta/Golf version is pretty much the same but the body is slightly different to fit in the beetle engine comportment; this is the only reason I can see for the change. I tested mine with a vacuum pump and it opened/closed but I think it was binding, not working as well as it should; common issue apparently. When I got the new one; it opened easier and I think possibly more then the old one. I just bit the bullet and bought it; haven't had any problems since.


http://www.kspg-ag.de/pdfdoc/kspg_pr...09_sec_air.pdf

KSPG AG - Secondary Air Systems & EGR

KSPG AG - Brochures

[CapnDenny1]

Thanks for the info. I'll buy a valve and a new hose in a few weeks. If only to get rid of the annoying growl after a cold start.

[Design]

I live just outside an area here in Texas that requires emissions testing so lucky me. I am hoping to find someone that is willing to do the work taking mine off, installing the block off plate, and cleaning up all the unneeded vacuum lines in exchange for a good working pump and the associated hoses.

JB

[Design]

VWVortex.com - FS: Lots of New Beetle Parts

Guy over on Vortex that is selling a pump and hoses. parting out lots of stuff actually.

JB

[ELDOGUY]

You can make a new hose for the combi valve by using 5/8 or 3/4 heater hose I forget which one a few hose clamps and a 90 degree bend . and using the old connectors from those crappy oem hoses I did it for about 12 bucks and it wont ever cause problems again .