[the4dunns]

I have a 2001 Windstar that is making a Flapping/Knocking noise. I am wondering if it is the intake valves. Does anyone have any ideas?

 

[S STORTZ]

Hi, my name is Steve. Sorry to here that you have the same trouble I do. My van has 141,000 k and I have that same low engine knock or loose parts noise, less noticable at idle, but louder off idle. Also on start-up. Periodicly I get a rough idle, but no stall. I have also had the check engine light come on, and the fault code was PO171 system too lean( bank 1 ) I had just read a forum about the intake cover box gaskets, vacuum lines possibly to blame. Sorry I can't tell which forum (i just stummbled on it ) If you have some info about our common problem I would appreciate the heads-up Thank-you in advance. Steve

 

[S STORTZ]

please see my posting . thanks

 

[Johnny Mullet]

A vacuum or an intake leak can cause "Spark Knock" that increases under load. You must address the problem to cure the noise.

The Windstar is common to have a lower intake leak. We replace the entire lower plenum to fix this issue since it comes complete with gaskets, bolts, and seals.