2006 Ford Freestar popping noise

Has the check engine light come on? Have you checked for vacuum leaks? When was the last tune up?

Okay, a tune up may be part of the issue. However, it could be a burnt valve or other internal problem making the popping sound you hear. Can you check engine compression?

Welcome back:

The IAC itself may be bad. It controls idle speed. Remove it and inspect it for carbon build up and also check where it goes into the throttle body to make sure nothing is plugging there. Here are the directions for removal and replacement. The attached picture correlates with these directions.

Removal and Installation
1. Disconnect the battery ground cable.
2. Disconnect the IAC valve electrical connector.
3. Remove the 2 IAC valve bolts and the IAC valve.
- To install, tighten to 11 Nm (8 lb-ft).

4. Remove and discard the IAC valve gasket.
5. To install, reverse the removal procedure.

Also, another common issue that can cause a stalling issue is the Crankshaft position sensor. Take a look through this link.

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

It shouldn't be causing a popping sound, but if timing is off, maybe you are hearing a slight backfire through the intake.

Welcome back:

The engine's ignition timing is entirely controlled by the Power-train Control Module (PCM). It isn't adjustable. We need to determine the clicking sound. I'm starting to question if it is a bad connection to the IAC or there is a problem with the PCM.

Do this, when you hear the clicking, feel the IAC to see if the noise is coming from there. Also, check the throttle position sensor the same way to see if something is going crazy there. We just need to know for sure what is making the popping noise. Are you certain it isn't a slight backfire through the intake?

Here are pictures of the TPS.

Let me know.

Joe