I've had (and still have ) numerous HVAC/ flapper door/temp dial, etc. probs on my 97. It's a terrible and spendy PITA system. Always had the stealership do it, and it invariably screws up again. Pressed em on the so-called warranty.
Sugg. a test on flapper door: Note interior vs. exterior pressure change, such as when windows are opened, or during a change between def. or floor/defrost?
Not sure if engine vaccum has anythign to do w/the system. Possible. Might explain flapp door sound on accel(?) I agree. weird.
I refuse to dig into dash probs on these things w/o a long weekend and a true fact service manual!
Nothing about XJ HVAC's surprises me! Got to the point where I can tell when the temp dial is going, and I'm about to have to do the flapper door for mine soon. Won't "mix" def/floor, and it goes to defrost only after a pressure change.
Advice if you're going to have it done at a dealers, do ALL of the HVAC prob parts : flapper door, temp mix door, etc. Very cheap parts (quality and price) but huge labor costs! Don't let the dealer insist otherwise. They KNOW they're junk, but want the labor $ later down the line.
yes, I've battled with them, and am a bit peaved and sick of paying to get the "luxury" of heat and cool and fog-free vision!
SHOULD be a recall IMHO, since vision is a safety issue, but you know Chryco would fight it tooth and nail, to save costs.
HVAC issues are a prob on virtually EVERY XJ!
Sorry about venting! No pun intended.
Good luck!
