soundquest 10 Posted March 25, 2014 Working on my friends new-used 1992 Corrado and I found the ISV disconnected after inspecting the engine. Hooked it back up, drove it around, parked it. Noticed a humming sound outside the car and inside the car with the keys removed from the ignition. Traced it down to the ISV which was still running. First thought I had was "this could be caused by a relay stuck in the close position." But I have no clue what is upstream of this guy that could possibly be keeping it on. Any ideas guys? Thanks in advance. Quote Share this post Link to post Share on other sites
seanl82 23 Posted March 25, 2014 Is it definitely the isv and not the aux water pump (look similar). The aux water pump remains on after switching off for a period to continue the cool down process. Isv usually buzzes for a couple of seconds on switch on, then quietens down. Quote Share this post Link to post Share on other sites
soundquest 10 Posted March 25, 2014 Good guess -- the reason why I know it is the ISV and not anything else is that it stopped running the minute I disconnected it (and I know what an ISV/IAC looks like having been around several SAAB's and other VW's with similar design and location of this component. I have read posts where folks have deleted this guy... but my intent is to fix the constant on issue and then clean the ISV and restore it. They will need it on the cold Winter mornings in Seattle (and during the Summer with AC operation). Quote Share this post Link to post Share on other sites
Purple Tom 0 Posted March 25, 2014 Can you post a picture of your ISV and the routing of the pipework? Some US cars have more in the way of emissions control equipment and I'm wondering what extra pipework your car may have? Quote Share this post Link to post Share on other sites
