pipes, compressor, bags, fuse and a relay!

[onetwentie]

Here are the codes:

(sorry didn't get to host them so its turned out to be two attachments instead).

[Delboy]

Now you have it out, you could try and find a local pneumatics / hydraulics supply shop and go round with the pump unit and see if they can adapt the output pipe to a pressure gauge and then you could hot wire like you did before to see what the max pressure is.

A new one pumps out 16 bar max so I anywhere between 10-16 should be fine, lower than that then you would be wish to replace the piston ring from bagpipe andy.

God luck

[onetwentie]

Can anyone shed any light on the error codes?

Also there are two pipes which you remove from te compressor, when pressure testing it does one need to be capped off?

Thanks in advance

[Delboy]

If you look at the schematic on page 18 of the ssp i attached earlier you can see the compressor 1, which pumps through the air drier (2) and then through (3A) non return valve.

So to test the unit you have to fit a pressure gauge onto the output line that normally connects to the Valve block down stream.

The normal position for the valves within the compressor are closed with no power to them which is great as it makes testing easy.

Once you have a gauge attached to the output, hot wire the motor as you did before and you should get a reading on the gauge.

The fault codes are quite generic and don't really say much as it could be telling you there's a leak or it may be that the pumps just worn out and the lack of pressure is giving the same error, In an ideal world the compressor would never wear out and the system then could say for sure there was a leak as it can't get the pressure to where it needs to be.

Only other way the system could say if there was a leak is via the height on each strut, but its more likely to be the compressor as they are well known to wear out.

Mines only done 50K and its already down to 10bar.

[onetwentie]

Having looked at the pump/compressor again, I realised that there is only one rubber pipe, which comes out vertically (though yes it is connected twice to the pump). I don't understand the schematic if i'm honest, so a bit stumped there.

Anyway another update:

took the pump down to a local guy who repairs gas systems for refridgerators and the like. He offered to put a gauge to it, and initially it looked like the needle on the gauge was pulling back, as if to show suction as opposed to pumping air out? he also suggested something to do with a one way valve, but I'm already confused!

Anyway, after a little while the pump decides not to work again! (and this is consistent with when I tried to give it a 12V feed whilst it was still on the car, I could swear it didn't actuate). So me and him both baffled we tested the wire further down the pump by piercing it with the probes from his multimeter, and yes there was power/current there.

The guy then concluded that the motor must be duff and suggested that I look at it. He actually encouraged me to open it and showed me what I would need to do.. so guess what? I did:





So as can be seen, most of the inside of the motor is a mess. The bushes (I believe that's what they're called? the 2 spring mounted metal things? seem to be okay.

I'm thinking to open the other side where the riveted panel is (the side with the crankshaft?) to see if I can open it more?

what do you think Del/Others?

[Delboy]

That doesn't look good, is thats whats left of the electrical connection?

If you or you gas guy has a read through the attachment I was on about there is pictures with numbers showing the pressure connection and suction ( Air in side)

[onetwentie]

Update:

RESULT!

After spend mucho time on this mini DIY fix it job, I have finally had a result and I'm delighted!

Turns out the one of the springs behind the brush had lost its 'springiness'. As a result the motor was going bad. The gas guy (who is now my friend!) said he'd previously helped a guy with a Q7 who had had a similar problem.

It turns out this guy with the Q7 works in/owns? the garage next door (tyres and exhausts place), and apparently still has all the spare bits lying in a box somewhere. His Q7 had other issues to from what I was told, and I'm not sure he had fixed the issues.. So my new friend suggested that I go around there and ask if this chap still had the spare bits from his motor.

Sure enough, I got the box (just gave it to me), and was about to swap one of the springs over, then decided to just swap the whole side section out (the part of the motor which has the two power cables running into it. Its a little tricky as you have to somehow retract the two brushes and the springs behind them before you can fit it onto the spindel of the commutator.

Finally got the motor working, and managed to get some air pumping. Although I couldn't get a proper reading, I tested it by placing my index finger over the output hole, and it was decent. Andy from bagpipingandy suggested this technique and said not to worry about getting an exact pressure reading.

So.. managed to put the whole thing back together (I had taken pics as I knew I would forget! )

Mounted it back onto the car, tested it by manually actuating the relay, and hey presto! we had a working compressor!

Switched the engine on for the moment of truth.. nothing.

Remembered car was in jacking mode, switched this off, straight away something, and then all the options become white from being greyed out, and its working again!!!

In summary, Delboy was right on the money when he said:

"The fault codes are quite generic and don't really say much as it could be telling you there's a leak or it may be that the pumps just worn out and the lack of pressure is giving the same error"

I believe that because the motor was on its way out and behaving, at best, intermittently, this was the cause for the errors.

The lights have gone out themselves, and I just need to get VCDS scan again to see if the errors have gone away.

I do feel that the kit from bagpipingandy would make it pump more pressure, but not sure how this would affect the air suspension? would it raise and lower the car any quicker?

Also, I was thinking to wire a buzzer or a light to the relay, in order to monitor how often and for how long the compressor is kicking in; mainly because I want to prevent it from heating up/burning out. That said, both my fuse and relay were fine.

Thanks to all those who read my posts, and especially to Delboy

Hope this has helped someone..

....shopping list now needs a VCDS cable and software adding to it!

[Delboy]

Good news fella, glad your cars back UP and running.

That green corrosion looks like there's been some manky water getting in around the end of the motor. :tut tut:

Keep a close eye on it over the next day or two because if there is a leak in the system your compressor will be on off too much and overheat.

Once you get settled into the car and purchase vcds you will then be able to see the pressure the system has.