A/C Trouble shoot

Hey,
My wife and I replaced the blender door part on the mixer door. Once we did that, we realized that the A/C still wasn't blowing ice cold like it did just before the blender door broke. The car is at a mechanic's right now, and they said they added 1/4 lb. of refrigerant, but it doesn't appear to be making a difference. I looked at the fan operation test, and I don't think that is problem. Please advise!

Sincerely,

Which car are you talking about [2002 or 2013]?
What is a blender door on a mixer door? Is that for diverting air through ducting or for making smoothies?

Hello,
I'm posting it here because it's for the 2002. It has 302,500 miles, so maybe the compressor is done, I don't know. I know it will be expensive if that's the case. The blend door is a well know problem with these cars, which is why we replaced the parts. Again, looking for advice.

Sincerely,
Dan Maldonado

Hey,
I am being told is the AC compressor, and it's going to run about $1200 is this pricing legitimate? I was thinking of getting a second opinion, please advise.

Sincerely,

When you turned the a/c on, are compressor clutch engaged?

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Is the system working at all? If your system blows cool air but not cold, your compressor is probably fine and its something else. Also it will blow much cooler when driving down the road. Sitting still won't get ice cold.

Common problem is the refrigerant control valve, bout 50 bucks. Have to take the back off the compressor, but not difficult. Seen many comp replaced due to this

Hey,
Thanks for the tip on the refrigerant control valve. I will ask the place tomorrow if that was checked. The system blows cool, but not cold, even after moving for 5-10 minutes. I heard the clutch engage even before we took it in to investigate. Thanks for the Q & A, because it's helping go into pick up the car tomorrow very well informed. Thanks!

Update: I got the car back this morning, the. A/C blows cool but not cold. I checked the fans with the a/c on and engine off. The fans are NOT turning. Please advise.

Sincerely,

You need diagnose the a/c system. Search the frume.the fan maybe stuck inside, i just replaced my driver side big fan ( the brush inside the fan stuck), righ now my a/c much cooler.

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We got the fans working again, by plugging and unplugging the fuse for it. Blows cool but not cold. The only other thing that happens is that if I don't leave it on the recirculate the air that comes in eventually gets warm, any advice on this? So now we will get the refrigerant control valve checked, and then maybe the compressor has died after all the miles on it. I will keep everyone posted.

Need to put the gauges on it and post the pressures.

Must shops aren't going to know about the RCV. It's inside the compressor.

A new genuine Sanden pump is $400. Maybe two hours for a pro. You do the math.

Get pressures with a manifold of the system: High and low pressures with it off, high and low with it on, and high and low with engine revved a little and compressor on.

Most likely cause is the RCV. Costs under $40 and can be replaced from under the car (take the back housing off the compressor with system EMPTY). Sure worth trying instead of compressor swap outright.

It could also be a blockage (ex. expansion valve), but the pressures will generally let you know.

So most importantly, the pressures.

1200 is ridiculous to replace a compressor. Autohausaz.com has the ac compressor for under 300. If you mechanically inclined you can do this and save money on labor. However, i do not see how someone can charge more then a couple hundred bucks for labor to replace the compressor

Just verifying the correct part number for the refrigerant control valve:
357820795J. Part cost $40.66 please verify, that this is the correct part for me before I order it! Thanks!

dan30thz28 said:

Just verifying the correct part number for the refrigerant control valve:
357820795J. Part cost $40.66 please verify, that this is the correct part for me before I order it! Thanks!

Click to expand...

It doesn't have a part number, as it is not sold by VW (they want you to buy the whole compressor)

Your part number is for a Schrader valve (filling valves), according to your description it is NOT what you're looking for.


You need this:
http://polarbearinc.com/webstore/index.cfm?fuseaction=product.display&product_ID=405&ParentCat=25

Make sure your compressor is the SANDEN SD7V16

Here is a thread about this. http://forums.tdiclub.com/showthread.php?t=283967

I highly suggest posting some pressures, and what you've done to diagnose first, before throwing money at it. Sometimes compressors do go out, but that means that the valves and seals are worn out, and generally will make noises/roughness when spun by hand with system off. When you spin it by hand, you should feel smooth resistance as if compressing something, but no roughness.

Guys, thank you for the responses. What numbers should I be looking for in terms of a pressure range (low-high)? Thanks for all your help, it is greatly appreciated!

Can't remember for sure off hand, maybe 30/180. Search.

If you buy the valve get the gaskets and some oil. Replace the same amount of oil as you loose. Should get a drier too.

Pressures given at idle:

Normal with compressor OFF:
-Low side 90psi-110, High side 90psi-110 (or thereabouts)

Normal with Compressor on:
-Low side anywhere from 25-45psi depending on how hot and humid it is outside.
-High side should be over 150psi. If you're approaching 250 psi + too often (and high speed fans kicking in) then it's overloaded.
-When revving the engine slightly, the low side should go lower, and high side a little higher (as it is pumping more).


Abnormal:

RCV (or even bad compressor):
Low side never under 50psi, even revving doesn't change much. Little to no cooling. Pipe never really gets cold.



Blockage of some sort:
-Blockage at expansion valve:
-Low side 0psi down to negatives (vacuum), high side very high, NO COOLING
-Blockage at condenser:
-Low side really high, high side really low, NO COOLING