OK, so I tried to search out some info on this before asking, and couldn't find anything that seem to fit the bill so I figured I'd start a new thread.

Here's my issue:

This has been going on for a few months now probably about the time the cold weather kicked in, but when I start my 2004X with 82K miles (only happens during a "cold start") a few seconds later it makes a very brief, but weird noise like something getting sucked through something. Doesn't matter if I keep the clutch in right after starting or keep it in neutral and then let the clutch out.

All fluids seem to be at the right level, with the exception of a steering box leak that I am using Lucas Power Steering Stop Leak fluid to nurse it through to the spring when I can work on it outside, which I have to add a bit every few days or so.

The noise feels like it's coming from right underneath the driver's seat since I can feel a bit of vibration in the shift knob during start up, but kind of hard to say since I can also feel it in the clutch pedal too when I have it pressed to the floor during start up.

Anyone have any insight/experience with this? Doesn't seem to be impacting the way my truck operates and the start up isn't rough, I just want to make sure it's not trying to tell me something bigger is on the way if I can avoid it by addressing the issue sooner than later.

Ahhhhh that sounds like the feul sending unit..

Nothings wrong. Mine does the same on cold weather start ups..