Is there an electric motor in front of the drivers side tire! I shut off the car and I hear a definite electric motor running. I believe it has to do with the coolant, but it’s electric for sure. It won’t shut off. I had to disconnect the battery.
could it be an aftermarket electric water pump?
It comprehensible supercharged with an aftercooler. Maybe it’s part of that?
I did notice that the heater blows cold when I stop and only blows hot when I’m moving, which makes me think of coolant is low.

 

Pretty sure now that it’s the Comptech supercharger aftercooler water pump. Don’t know why it’s not shutting off though?

 

If your car is a 00-05, its probably the secondary air pump. The noise would be coming from the left front bumper area.

 

The secondary air pump should only run when the car is running and on cold start, it sounds like a vacuum cleaner so it's very noticeable.
From what you are describing it seems more likely to be a water pump just like you said.
It should have a relay and that might have failed in closed position which would make it run all the time.

 

Yes, the second air pump should only run at cold start, it is meant to help the catalyst reach working temperature faster.

 

You guys are great!! Thanks for the replies. It hit me last night. Like you say, the relay. I looked up the install instructions for the Comptech after cooler and it does use a relay. I’m pretty sure like you guys are saying it’s just stuck in the on position. Unfortunately you have to take the wheel off, and the inner fender well out to access, but as far as cost and complexity it’s not too bad. I’ll follow up when I get it sorted.

 

Yep. It was the solonoid. I took the inner fender out to reveal the solenoid. I hooked up the battery and the pump ran until I smacked the solonoid, then it stopped. New solenoid on order. Thanks again for the input.