Replaced rear evaporator core / 08 caravan

[Mark72]

I have a 2008 Dodge Grand Caravan and the AC systems was hissing like crazing. Found that the rear evaporator was leaking so I had it replaced. After refrigerant and O-rings, labor, etc... it was 800.00. So I get this stupid thing back and its cold. No more hissing. No more leaks. But now it makes a god awful sound that starts in a moaning sound and lasts for like 10 seconds and ends in a screech. The sound starts from the inside of the van in the back passenger side where the part was replaced. I took it back to my mechanic and he had it for 2 days and naturally it wouldn’t make this sound for him while he was driving it around. Just to be clear, it’s not brakes. It will actually do this when the van is stopped at a light or stop sign. I’m not worried about my mechanic not backing up his work but he has to hear it do it. He told me to bring it by while I’m driving it if it does it again, and of course when I got it back it did the next day. LOL. He did say until he can hear it, the only thing he can think is that maybe there is a glob of lubricant being pushed through the line. Would that make sense? And if so, should it dissipate as the lubricant gets pushed through the lines?

 

[Lubener]

He may have overcharged your system and the screech you hear is the a/c belt.I would take it back because his explanation is pure non sense and it didn't make those noises before.Did he evacuate the system prior to recharging?

 

[mehullica]

Can you duplicate the noise by actuating all the modes for the rear A/C? Could be a bad servo motor. Try switching floor, roof, & cold to hot. See when it makes noise.

 

[Mark72]

The noise is not located where a belt even exists. It's in the rear near where the evaporator wad replaced.

 

[The_Eric]

Do you have a rear blower fan too? If so, it be that making noise- heard many that made similar noises to what you've described.

 

[JTK]

The only moving part back there is a fan, but there is the evaporator core, expansion valve, etc. Like said, I'm wondering if this is associated with too much or too little of a charge making a racket when forcing itself through the expansion valve?

Ugh.. Dreaded rear HVAC issues are the bane of minivan ownership. So much simpler if you can get (and tolerate) one w/out it.

 

[WobblyElvis]

Those vans must have an electric door actuator to direct the air up to the ceiling when on ac and down low when in rear heat mode.
The actuator could make a moan/screech noise when moving. Perhaps this door actuator got out of sync when the work was performed and is now hunting for position. Older Chrysler minivans had a self test/re-calibrate operation that could be performed by just pressing the climate control buttons is the right sequence. Youtube may have a video on this procedure for your van.

 

[bdcardinal]

I was about to ask if this had a blend door motor/actuator. The Explorers and Expeditions do and we replace a bunch of them.