What is this noise on start up?

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Shantheman73

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From a 2014 post from sambo in this forum:

Air conditioner compressor noise

The noise you hear from the a/c compressor when it is first turned on is caused by where the compressor is located. I bought a new 2004 Ex pedition and it made this noise Ford calls (get this) CHUGGLE. I brought the truck back to the dealer so many times and was a pain in thier ass they finally printed out the service bulletin. It said "this cannot be repaired if you try to repair it, it will still make this chuggle sound and Ford will not reimburse you for the work if its under warrenty". The sound is caused by the liquid refrigerant and oil collecting in the compressor under certain conditions. Because the compressor is the lowest point in the system, poor engineering. The shop manual addresses this issue, in the manual its called "slugging". Ford was supposed to program the ECM to engage the compressor clutch while the engine is cranking to push out the liquid and oil slowly. Apparently this doesn't work. the dealer said this "will not hurt the compressor". I just retired after being an auto and truck mechanic for 47 years and this is BS the compressor is very delicate and won't take that for too long. It happens when the sun heats up the interior of the car causing the gas in the a/c system to expand forcing the liquid into the compressor if you notice this don't happen at night or in colder weather. To prevent it and save the compressor shut off the a/c before you park the car for several hours, when you restart the car DON'T turn on the a/c until the engine has fully warmed up, about 5 minutes. Hope this helps

I’m curious if you or anyone has the service bulletin addressing this?


2007 Ford Expedition Limited
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07navi

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There is only supposed to be refrigerant (Freon) in a gas form inside the compressor at all times. If liquid refrigerant or an excess of oil settles in there while sitting it will choke on it until it passes as long as it passes quickly, if not quickly it will ruin the compressor. Too much refrigerant or too much pag oil can cause this, so get the gauges and check it out.
 

BlueStangGT

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I went through the same thing last year when I bought my '14 Limited. It had previously been sold as CPO vehicle and thus had a 100k powertrain coverage so I wanted to make sure that any issues were addressed before the 100k was reached. I couldn't identify this sound and, after several trips to my Ford dealer and conferences with the Shop Manager, we concluded that this was the same "slugging" that you and many others here have experienced.
 

Shantheman73

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I went through the same thing last year when I bought my '14 Limited. It had previously been sold as CPO vehicle and thus had a 100k powertrain coverage so I wanted to make sure that any issues were addressed before the 100k was reached. I couldn't identify this sound and, after several trips to my Ford dealer and conferences with the Shop Manager, we concluded that this was the same "slugging" that you and many others here have experienced.

Did they replace anything or just tell you it’s normal?


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07navi

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Definitely not normal and it will grenade the compressor if it can't spit out the liquid quickly enough and they are expensive. I slugged my last truck when I put too much refrigerant in it, it locked up, and the belt was squealing but luckily it spit out the liquid soon enough. Another few seconds of that would have cost me $500 +-. Other parts in the system can determine whether the refrigerant enters the compressor in a gas state like it's supposed to or not, besides overfilling.
 

akacolonel

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07navi made a good point. I shut my a/c off when I park truck. Next morning I Wait for a few minutes after initial startup then turn on a/c, and no noise.. good call!
 

BlueStangGT

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Did they replace anything or just tell you it’s normal?


2007 Ford Expedition Limited
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Nope, didn't replace anything as the AC was and is working like a champ. I honestly don't recall the word "normal" being tossed around although we did conclude that it's not unusual. I specifically asked him if he was comfortable with a vehicle making this noise and he said yes. We were also working with one of his line mechanics who's experienced the same issue. All this was going on around the 99k mileage mark and now my Expy has about 104k. Neither my '05 2WD XLT or my '07 4WD XLT exhibited this noise which is what really had me spooked to begin with.
 
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effingpot

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HOLD ON...DON'T SPEND ANY MONEY!

So the car is for that paint job in the other post and the garage have this post to read too.
They are saying why not just refresh the AC system, suck out the old stuff and replace with new. Will that do any harm or good?
 

07navi

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So the car is for that paint job in the other post and the garage have this post to read too.
They are saying why not just refresh the AC system, suck out the old stuff and replace with new. Will that do any harm or good?
You could but it won't cure the problem. It sounds like a bad orifice tube or expansion valve depending which one the vehicle has. The refrigerant needs to be in a complete gaseous state when going though the compressor.
 

JExpedition07

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We replaced everything with new OEM components on my last 2007 that had slugging problems after the compressor clutch seized. New compressor, new tube, new filter drier and new refrigerant with correct pressures and it still slugged. My dad owns a refrigeration business and has large accounts such as Pizza Hut and he did the charging when I finished the job. He also flushed the system. Common issue on these trucks and it’s the oil collecting where it shouldn’t. Warm up the engine then it won’t happen because the liquid will move away from the compressor. They sell desluggers as well that rapidly cycle the compressor to ease liquid past the valves. The problem is valves aren’t made to fight compressed liquid, same as your engine. They can bend and lock up or just slowly wear out due to the slugging.

If anything you’d have to try a flush and a new charge since it’s excessive oil.
 
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