2010 Air conditioner compressor grind on start up?

I wouldn't think something making a grinding noise as this does (and now apparently a Dodge) would be "normal." Per Fatal Exile's last post, his repair seems to have resolved the issue, however I'm not so sure that everyone is going to be as fortunate to get a dealer to make such a repair unless there it truly is a "known issue" and has a TSB that's been issued and I'm not aware of such a bulletin (if someone else knows otherwise, please let us know). I have about another 6 wks left on my "all encompassing" 1 yr. warranty and I really appreciate any and all info possible before my 1 yr warranty is up.

Plannerman99, you didn't mention but I'm assuming you have a new Dodge; have you been back to the Dodge dealer about the noise, what did they say?

 

I haven't been back to the dealer to ask about her Dodge yet, but will soon. I'll let you know what, if anything, they say.

 

I have a 2011 4X4 Taco and it is making the same a/c "grunt" noise. This has been a great forum for finding information, and now I feel like I have hit the jackpot (thanks Fatal Exile). I too bought my truck from Avondale Toyota, and use them for my service. I will try to get them to repeat your same service steps to mine and post back with updates.

 

*BUMP*

Anyone have any info on this? Mine is doing it, too.

 

The sound you are experiencing is liquid flood-back to the compressor. In the off-cycle, liquid refrigerant migrates to the coolest position in the system, being the evaporator. When you start up your A/C when it's been shut off for a long time, the liquid accumulated in the evaporator slugs the compressor inlet and causes the noise you're hearing. Compressors are meant to be a vapor pump, so the liquid is actually causing damage to the compressor's valves. The easiest way to fix it is to regularly run your AC system.

 

Very interesting. Thanks!

 

Run mind darn near every time I'm in it, all year long, and it still makes that wrenching grunt when you turn it on.....

 

Yeah, mine has been doing it almost every day this summer. Mostly happens when I leave work and it's been sitting in the heat all day.

 

my compressor is locked up so it dont work at all

 

Well, it's not just ours, it's nearly every AC system that doesn't have a pumpdown solenoid or some means of keeping the refrigerant in the condenser during the off-cycle.

That is why, if you are an absentee homeowner, you should keep your thermostat set at something like 80-82 degrees rather than just shut off all of your disconnects or circuit breakers- so the system runs occasionally.



Another down-side to liquid migration is that compressor oil usually migrates with it- leaving you with an under-lubricated compressor that slugs on start-up. Not a good situation.

 

Exactly- the refrigerant wants to stack in the evaporator, probably because your condenser is sitting dormant at 110+ degrees, or maybe even quite more as engine heat dissipates or direct sunlight shines on the front of your truck, and your evaporator in the cab of your truck is going to be substantially less than that.

At 110 degrees, the R134a in your condenser is going to be at 147 psi. Say the inside of the cab of your truck is at 80 degrees and your evaporator matches that temperature, the refrigerant is going to be at 86 psi. Hence it's inclination to migrate.

 

Why haven't I heard this noise from any of my past vehicles?

Is there anything that can be done to ease the grind & make the startup easier on the compressor?

Sorry to bombard you with questions, but I see that you're an HVAC tech

 

Argh, mine does it daily. So, if the logic is to run it more because it causes damage , then i'd just have to leave it off for a month at a time instead of daily so as to do less damage that it does do.......daily.

Who makes these things for toyota n dodge? k-mart?

 

Mine dose the same thing ! i never drive dirt roads just normal 30 mile commute to work . and every once and a awhile it makes a grinding sound