turner15429

hello I’m currently having problems with my air conditioning on my W211 320 2006. It’s been working pretty good but all the sudden it’s not there’s no refrigerant moving through the system. it’s like the ac compressor is not turning on. i noticed that STAR diagnostic says that the bolt in the center should turn but it does not turn with the belt pulley as specified. it says i need a new air compressor. would you guys say that’s accurate? i was wondering if it could possibly be the analog metering solenoid valve attached to the compressor. because i thought that this type of compressor had no clutch.

i’m trying to do everything myself, but I want to make sure I’m not throwing parts at the car I have XENTRY star diagnostic and I can communicate with the air conditioning module using a cheap pass-through device.

it’s been really hot out lately and my wife has been on my *** to fix her air-conditioning. Any help is greatly appreciated.

Heguli

These compressors turn constantly, as there is no clutch. So it appears that your compressor has seized if the center bolt does not turn. IIRC, there is a fail safe on the compressor pulley, if the compressor should fail it won't destroy the whole belt drive.

juanmor40

There are two visual tests:
1 - Does the shaft turns when the engine is running?
2 - Does the shaft turns by hand when the engine is NOT running?

(2) is needed if the answer to (1) is negative. You need test (2) since likely causes for a fail on test 1 is that the permanent coupling is broken. Why is the permanent coupling is broken? random failure or the compressor is seized. For the latter you need a new compressor; however, do NOT install a new compressor until you understand why it seized.

Sometimes the coupling itself fails, but the compressor is still if fair (not necessarily great) condition. However, if the compressor is seized, the coupling is torn to pieces to prevent a catastrophic situation under the hood.

tjts1

This is the correct answer. Unfortunately you do need a new compressor. When you remove the old compressor, drain the oil out of it into a cup, stir it up and look for metallic flakes in it with a flashlight. If the oil looks sparkly, then those metallic flakes are also spread throughout your AC system. You will need to flush the entire system and replace the AC condenser. If you don't do that, the leftover metallic particles will destroy your new compressor.

juanmor40

Include the dryer as well, and since you are already getting a compressor, condenser, and dryer you might as well throw in a new expansion valve. Basically, the only things left are the evaporator, hoses, and sensors.

When getting the compressor, be certain you are getting the correct one with or without the diode in the ECV. Some MB uses it some do not because it is already in the ECU.




Below taken from a W212 thread ( https://mbworld.org/forums/e-class-w...ml#post8699364)
Summary: MB AC systems with VariableDisplacement require a diode (let you read the why), but the diode can be installed in different places, i.e. fixed after the fact. So, there is quite a confusion in the aftermarket of ECV about MB requiring a diode since it is MODEL dependent. That is, if MB installed the diode in the ECU, it does not need a diode downstream. I guess once a platform with ECU that is designed w/o the diode, it must be added elsewhere

turner15429

Yeah, I’m away working right now so hopefully soon I can fly home and fix it. Is there anyway to tell what kind of control valve it has without getting under the car and looking? Is there any reason I can’t use my old control valve? I’m trying to order the parts ahead of time, so they’ll be there when I get home to visit my wife can always connect my laptop to the car so I can look at anything in the diagnostic software if that helps. Also, my wife is able to turn the compressor shaft by hand using a wrench, it turns fairly easily.

turner15429

How hard should it be to turn? It turns by hand using a wrench.

tjts1

You should be able to easily turn it by hand.

turner15429

is there a way to tell what kind of valve it has without looking at the compressor? Could I just plan to use my old valve?

juanmor40

A new compressor will come with its own electronic control valve. That should not be an issue. The important part is to get the correct compressor, and not an OEM from a seller saying it is MB compatible. That is when you need to know the details.

For the M112 engine, I think there is enough space to take a picture of the compressor's label to see the specifications. I expect it to be one of the 2 in the photos I posted. Note they have different-sized pulleys. Do not go by the MB car model, i.e. E320 means nothing except that there are 2 different compressor models.

As I said earlier, if the shaft does not rotate with the engine, but it does manually (which is rare) there is a slight chance the inner guts of the pully are damaged. Here is a video on how to check the inner parts, is it trivial? depends if you have the tool to lock the pulley while you turn the nut out

Here is the tool ( )


If you remove the compressor from the vehicle (your call)

tjts1

New compressor comes with a new valve. I wouldn't reuse the old valve because it is likely clogged with shrapnel from the failed compressor. The compressor pulley is a failsafe mechanism when the compressor locks up.

turner15429

I got the Mercedes-Benz part number from the dealership and crossed referenced it to a DCP17062 but I noticed the control valve looks different than mine? My valve has a yellow dot and the new one has a triangle. Also, how much oil should I put in the new compressor and how should I add more? Like can I add all I need just by putting it in the compressor or do I need to inject it as I fill it up somehow?

juanmor40

Those are the specs for that compressor model. Yellow dot or triangle means DIODE in the valve, so that should be fine. I would like to find out how you cross-reference the DCP17062 to the E-Class. The Denso catalog I have only shows the DCP17062 for GL 320/420/450, ML280/320/420/450 R280/320. Notice the pattern: X/W164 platform.

turner15429

I got the part number from the MD dealership they gave me part number 001-230-12-11-80 and I crossed referenced it on a website to the compressor I bought dcp17062

juanmor40

Here are some files that may be useful

juanmor40

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turner15429

Yep I got the wrong compressor but it has the same pitch grooves and is just an wider pulley. Vacuumed it for 1.5 hours and loaded it with 34 oz of 134a and it’s working used 2 oz of pag 42. I flushed everything and replaced the dryer and condenser I only cleaned the expansion valve rock auto sent me the wrong one. I also forgot to discharge the manifold on the high side before disconnecting do I need to be worried about any lost oil or refrigerant?

juanmor40

Great you got it working

Since you have XEntry, you can monitor the temperature in the evaporator, and pressure of the refrigerant. I would also monitor the manifold low and high pressures.
1 - Turn ON the engine, and rev up to @1500RPM
2 - AC on MAXCOOL
3 - Monitor Evap Temp, fingers crossed it is @5C min, anything lower is bonus
4 - Monitor Refrigerant Pressure, @180+ PSI, @13 bar
5 - Check your ambient temperature sensor reports something reasonable, as well as the interior temperatures. There are two sensors: one near the ignition key (little screen), and on the overhead control panel.
6 - Check for codes on the sun sensors, and pollution sensor. If there are codes, the AC starts to misbehave. All of the sensors together try to control your comfort settings, i.e. AUTO mode.