Aircon problems on Jetta 5 1.9 tdi

[WillemT]

Hi

So I've been having an aircon problem on my jetta 5 from the day I bought it(76 000km). Unfortunately it was already out of warrantee so the issue must now be sorted out by me...

After finding a thread on tdi club I think I might have found an explanation to the problem.

Firstly, my aircon was working but only when it wanted to.

The car has a climatic aircon with no AC button, meaning that the AC is permanently on and you can only turn it off with the ECON button.
The possible cuase to this could be that the RCV (Refrigerant Control Valve) is faulty. It sounds as if this was a common problem on the SANDEN compressors, at least in the US. The valves tended to get stuck and not always function properly with the problem starting as the AC just taking longer that average to start cooling.

For those not familiar with the variable displacement AC pumps, the valve control the flow through the pump and the displacement of the pump is determined by the flow. So with a stuck valve you will either have a aircon that freezes you out(but the valves seam to never really get stuck in the open position) or a AC pump which is not pumping at all.
Now the dealers option and answer is that you have a pump problem and they will install a new AC pump as they don't replace parts, rather whole units where they can. (same like they wanted to replace my turbo for R32 000 when the bypass pipe was broken, R1 200).

In the case where the valve is the problem there is really NOTHING wrong with the pump, which by the way is not the cheapest part on the car.

After looking around I found a PXE16 valve for my SANDEN 8681 compressor.

Ordered the valve earlier this week for R495 + R150 courrier cost from Durban. Unfortunatly the top part of the valve has a crack and I'm busy sorting it out with the supplier. The valve is going back via courier and I would hopefully have a new valve before too long.

Once a 100% working valve without any cracks is in my possession I will have it installed and report back if the problem is solved.

If anyone else have had issues with climatic aircons can you please post and give a brief description of what your problem was and what you did or had done to solve it?

[WillemT]

Photo's of the valve and the crack...

[WillemT]

So I recieved my pxe16 valve from the supplier on the 6th of January, this time one without a crack.

Had it installed on the 13th Jan 2015 and the aircon was back in operation. The guy that installed it however mentioned that although the aircon started working immediately after he installed the new valve the fans still didn't switch on so it only worked for a while till the system pressure went to high. He then found a lose wire on the high pressure sensor which was responsible for switching on and controlling the fan speeds.

So after all of this I have a 100% working aircon again. Cost me R495 for the valve plus courier cost and R900 for the fitment of the valve, re-gas and re-oil of the compressor as well as fixing the loose wire.
In relation with the previous VW quote that was R14 000 for a new aircon compressor ex labour I'm more than satisfied with the outcome...

I bought the PXE16 valve from Martin's Car Parts in Durban. Although disappointed to receive a valve that was cracked they did replace the valve with a new one. I believe the valve might have cracked from over tightening of the internals during assembly, and then starting the crack when it was couriered as I could see that the crack was bigger the next day after I recieved it just before I sent it back.
I was completely satisfied with the way Martin handled the situation and he didn't try to back away at all.

Hope it can help someone with the same problem as I needed to look/dig quite far to get a diagnoses and solution for the problem.
According to some post on the tdi club forum this could also be the cause of aircons not blowing ice cold air as this valve is responsible for the displacement in the aircon pump and if it doesn't open up enough you will in effect sit with a very "small" displacement aircon pump... And although the problem is in the pump, the actual pump is still working fine...

[zane.mk1]

Could this be the same for the other models? i.e 1.6, 2.0 non climatronic

Mine also just stopped blowing ice cold air and all the places I had it tested said the compressor must be replaced.

[WillemT]

Mine has the climatic aircon not climatronic.

The climatronic is the full climate control one (not fitted in mine)
- Cab temperature is measured and the aircon will cool down as fast as possible to get cab temp down to the set temp, (I think air vent temp is also measured but the aim is to get to cab temperature, and the setting you set it at is for the cab temperature)
- When set on auto it also adjust fan speed to cool down (or heat up) as quick as possible to reach the desired cab temp.

The climatic is a partial climate control feature brought out in all models that doesn't have the full climate control. If you have an ''econ'' button in place of a ''ac'' button then you have climatic ac, if there's a ''ac'' button it's a full manual air con, or at least more manual that the climatic.
This normal jetta 5 air con was changed back from the half automatic climatic to a full(or more) manual air-con between 2009 and 2010 I believe. When the dash board upgrade happened to the Jetta 5 they changed it back. (as far I as my knowledge go)
- Air temperature coming out at the vents was regulated to what you set it at on the dial, or as close as possible.

I'm not sure if the later more manual air cons will also have a variable displacement ac pump but they very well might have.

So all in all yes it might well be the problem in your car as well.

Just for interest sake, does the ac cool down at least a bit still?
What model and year do you have?
If you can possibly get the model number on the ac pump it will also help to determine the pump type and make and then look at possibilities for it not functioning 100%.

[WillemT]

Just saw in you signature you have an 08 model.

I checked a photo on gumtree of an 08 model. Looks like it already might have the more manual aircon.
It doesn't really matter, the thing that matter is if you have a variable displacement pump, and I'm quite sure it will...

Did you have the car by VW yet? or are you a bit scared of the stealers?

[zane.mk1]

Thanks for you reply, I just have a "AC" button. Absolutely no cold air when I switch on the aircon.

I have not taken the car to a dealership but a buddy hooked me up with a second hand one.

I am just trying to figure out what the problem could be seeing this is quite a problem on the mk5.

[WillemT]

The common problem on them, and that is here and in the US, is the valves on the SANDEN ac pumps stopping to work or starting to stick.
Does your fans switch on when you put the ac on? There is off course the slight possibility that they might have gone back to a compressor with an electric clutch, which mine doesn't have. And if that is the case then you'll probably need to replace the pump. I think they go for around R5 000 new. Just don't buy from a VW dealer. You can get a genuine SANDEN pump, the same one you get from the dealer, from other suppliers for around R5 000, the dealer will ask you about R14 000.

If you can get the serial number on the ac pump you'll be able to determine compressor model and get the correct RCV.

If you want to take the car to a dealer let me know. I know a auto electrician at a VW dealership in CPT (basicly city centre) who will be able to tell you what you need to replace and what the real problem is.
I supplied them with the RCV and just asked them to fit it. I don't know if the normal guy on the street always has the right software to run proper diagnostics on the cars to really determine where the problem is.

''I have not taken the car to a dealership but a buddy hooked me up with a second hand one. ''
A secondhand compressor or RCV?

[Howie-WP]

*necro thread revival*

Been looking for one of these for my Mk5. I see plenty on Amazon. I have emailed Martin's to find out if they still supply.

@WilliamT, how long did the replacement last?

[Howie-WP]

I messaged Martin's ..... price now is R1150 and R280 freight. It is cheaper (fractionally, including 50% duty) to get it from Amazon, gonna see if they do black Friday deal or similar.

[Howie-WP]

Sheesh..... I forgot to phone a friend

[Black Widow]

Thanks for sharing as this is a common fault on Mark 5 cars fitted with those aircons.

[Callum229]

Bought mines from Banggood, worked perfectly. I think it was R450 with shipping and came within 20 days.