Quote:
Originally Posted by arucano
I don't have an e92 but is there a vacuum hose running to the valve? On other BMWs the vacuum hose fails as it ages and prevents the vacuum from opening the valve. If there is a leak in that line there will be less vacuum to open the valve. If the valve is fouling/coking up, it may work when hot but not when cold. If there is no vacuum line to the valve, then the design is probably a "check valve" that opens on the pressure of the pump. In that case, the check might be sticking closed. You can try spraynig carb cleaner or something similar into the line from the pump to the valve and going through a few cold starts and see it that helps to free up the valve.
Also see the other post where the pre-cat O2 sensor was the cause.
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Hey, thank you so much!
I believe it's just 1 tube going from SAP to the valve, and then valve into the block. I presume it's a check valve.
The cold start does seem to work.
I have dumped seafoam into the tubes leading to the valves, and its been coming out of the exhaust as well. So I presume that means the valves are either stuck open working properly?
I also did replace the upstream o2 but still have that code.
Very strange/mysterious issue...
Thanks again!