A/C question

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Mar 24, 2010 | 04:37 PM

aft2005exp

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From: So. Cal.

A/C question

Hi everyone, today I turned on the A/C in my 2005 EXP EB (97.5k) for the first time this season in SoCal. When I turned it on, there was a loud clunk from under the hood for an instant, and then ran fine. Cold, no problems, no other noises. At 67k, I replaced the serpentine belt for preventative measures. I have heard of noises and issues with this gen's rear a/c. Does anyone know what this may be caused by? Compressor ? etc? Any leads, please let me know.

Mar 24, 2010 | 08:06 PM

alloro

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The compressor could've just been a bit stiff from going unused for a period of time. This could've cause the belt tensioner to bounce, then recover. The other possibility is that your compressor mounting bolts are loose.

Mar 27, 2010 | 06:31 AM

dave e

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refrigerant oil doesn't stay spread though out the system during long periods, it attracks to itself so this could have created a hard start for the compressor. if the problem persists then this isn't the problem

Mar 27, 2010 | 07:11 AM

mvoeller2

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I have an 04 expy and mine does the same thing about 50% of the time I start the truck up when the AC is engaged. Sounds just nasty. But I thought I read somewhere that it is kind of a "normal" noise. Could be wrong on that though. Been doing it since I bought it 2 years ago, and AC still works great.

Mar 27, 2010 | 10:17 PM

mtondreo

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From: Pinellas Park, FL

mine is an 06 and the dealer actually printed out the TSB for it (will try and find the work order) - short answer is that it is normal. It goes into an explanation of it also, but can't remember what it was. Mine almost sounds like a grind or something engaging - kind of like enagaging a PTO. I have started shutting the ac off when I first start it just because I do not like the sound, it seems to keep it from happening. Thanks, Mike

Mar 27, 2010 | 10:25 PM

mtondreo

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From: Pinellas Park, FL

Found it - not a TSB. It is a OASIS SPECIAL SERVICE NUMBER 19311

"

19311 2003-2006 EXPEDITION/NAVIGATOR - MINIMIZE GRUNT/POP NOISE BY TURNING A/C TO VENT BEFORE EXITING THE VEHICLE - DO NOT
REPLACE COMPONENTS

SOME VEHICLES WITH AIR CONDITIONING UTILIZING R-134A MAY EXHIBIT A MOMENTARY GRUNT/POP AFTER BEING PARKED FOR SOME TIME &
THE COMPRESSOR IS ENGAGED BEFORE THE ENGINE COMPARTMENT HAS WARMED UP. THIS IS DUE TO LIQUID R134A BEING PUMPED OUT
OF THE COMPRESSOR. R134A WILL TRAVEL TO THE COOLEST POINT (THE COMPRESSOR) ONCE THE ENGINE HAS COOLED, DUE TO THE
DIFFERENCE IN TEMP BETWEEN THE ENGINE COMPARTMENT & THE VEHICLE INTERIOR. WHILE MANY VEHICLES HAVE PCM STRATEGIES THAT
ADDRESS THIS BY REPEATEDLY CYCLING THE COMPRESSOR ON START- UP, THIS MAY NOT TOTALLY ELIMINATE IT. REPLACING A/C
COMPONENTS WILL NOT ELIMINATE THIS. COMPONENT DURABILITY IS NOT AFFECTED. MINIMIZE THE NOISE BY TURNING THE A/C SYSTEM TO

VENT BEFORE EXITING, & IN MILD AMBIENT TEMPS (APPROX. 50-75F) WAITING A FEW MINUTES BEFORE TURNING ON THE A/C OR DEFROST."

from http://ww2.justanswer.com/uploads/bo...expedition.pdf

Hope this is allowed because I sited the source - my actual source was in print though.

Thanks, Mike

Mar 28, 2010 | 01:41 PM

alloro

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Quote:

Originally Posted by mtondreo

MINIMIZE THE NOISE BY TURNING THE A/C SYSTEM TO VENT BEFORE EXITING, & IN MILD AMBIENT TEMPS (APPROX. 50-75F) WAITING A FEW MINUTES BEFORE TURNING ON THE A/C OR DEFROST.

This doesn't happen with other vehicles that use R-134a refrigerant. Sounds like yet another design flaw that a manufacturer won't own up to.