The error looks like 

```
fail [k8s.io/kubernetes/test/e2e/framework/framework.go:338]: Sep 17 05:10:50.330: Couldn't delete ns: "e2e-test-image-change-build-triggger-rpdgr": namespace e2e-test-image-change-build-triggger-rpdgr was not deleted with limit: timed out waiting for the condition, namespace is empty but is not yet removed (&errors.errorString{s:"namespace e2e-test-image-change-build-triggger-rpdgr was not deleted with limit: timed out waiting for the condition, namespace is empty but is not yet removed"})
```
from https://prow.svc.ci.openshift.org/view/gcs/origin-ci-test/logs/canary-openshift-ocp-installer-e2e-gcp-4.2/308

Chasing this through the KCM logs, we can see that namespace deletion starts sometime before 05:01

E0917 05:01:11.157191       1 namespace_controller.go:148] unexpected items still remain in namespace: e2e-test-image-change-build-triggger-rpdgr for gvr: /v1, Resource=pods
E0917 05:06:25.855298       1 namespace_controller.go:148] unexpected items still remain in namespace: e2e-test-image-change-build-triggger-rpdgr for gvr: /v1, Resource=pods
I0917 05:11:30.194300       1 namespace_controller.go:171] Namespace has been deleted e2e-test-image-change-build-triggger-rpdgr


There are lots of other repeat messages as we backoff for an extended period of time, but the most noteworthy bit is that it takes over 5 minutes to delete pods.  Volume detach seems like a reasonable thing for a first check.  I seem to recall that we thought we had a problem on GCP in 3.11.