S-trim make noise

I've had a v-1 on my car since about april, no problems at all. I had the fitting for the return line welded in the oil pan never had a problem. Now, I just put a canton oil pan on, did the same thing, had the fitting welded into the pan right were it is supposed to be. Now when I start the car and let it run for about 30 seconds and shut it off the blower is making a gurgulling sound for a few seconds. I pulled the return line off the pan and no oil comes out the fitting so the oil level is below the fitting. I started the car with the return line off and it deffinatly is getting oil. I also called vortech and talked to a tech and he has no idea what it could be. Anybody have any idea what could be causing the gurgulling noise?

Thanks
Ryan