lewisweller

Mike, whip off the intake Y pipe and grab the water pump pulley. If you can wobble it likely it's worn out and leaking from the front. Leaking could also be a pipe in there somewhere like the one that run coolant to the oil cooler and alternator? Fyi if you change the water pump (and replace the pulley as well because they crack and mine exploded when the garage did the head gaskets last year) you just need to release the belt by turning the tensioner item 17 clockwise with a spanner slipping the belt only off the water pump pulley (making it easy to put back on, replace the belt if worn or old) and then unbolt the water pump. What ever coolant leaks out will be about 1-2 litres which is easy to refill after putting new pump on with the new metal gasket don't forget. And also torque bolts correctly in a normal diagonal sequence or it will leak if too tight or too loose. After 1 day, check coolant again when engine is completely cold and top off coolant again then your good to go.

Good news the AC is fixed. Hooray. Fyi you don't need to remove the compressor to take out the valve, it would be easier but the time to remove and refit means I just worked around this with the guys in the garage to make space. Circlip pliers won't get in there so carefully using two long small flat blade screw drivers we massaged the clip out and reverse to install after. To allow the control valve to drop out (oring makes it sucked in there a bit, needs a good tug with pliers to release) then pull the rigid line in the way slightly over to allow valve to drop out downwards. The old compressor control valve was very warm to the touch and I think the solenoid was just totally jammed and thus it don't work mechanically. Inside was clean and no debris found. The old one has a plugged wiring harness where as the new one was hard wired. When that valve works you can hear the compressor kick In and hum under load, if that valve is stuck or not working it pretty quiet. That might help some others to diagnose their compressor control valve in the future. Symptoms: 1. Generally Poor AC performance and sometimes could be intermittently on then suddenly off and not cooling. Or it just won't cool at all, blows hot or ambient air. 2. Possible fault code for "open or short circuit in compressor". I didnt have a code but it could generate one if wiring was damaged or control valve melted or shorted internally. 3. Low side Gas pressure higher than normal, high side either normal or lower than normal. 4. When AC is running, press the "economy" button which will kick off the compressor (remember no clutch here so don't bother looking at the pulley Wheel unless it's sheared off because the compressor is seized up) if when you press the economy button off again and the compressor is not heard to come in and hum under load then likely the compressor control valve is faulty. Assuming the AC controller is working. 5. If your front AC is working and the rear doesn't, or left side is good but right side is warm this is not a compressor fault. You need to look at flaps or the individual evaporator/ expansion valve for blockages but most likely the AC charge is low (750grams for 2 zone AC and 1100grams for 4 zone AC systems). 6. Lastly with vagcom or duremetrics look to make sure the AC controller is requesting the compressor on and that current is showing like 0.8amp or something and a % of load is also shown. Bad news whilst the car was on the lift at the garage it dumped all the power steering fluid out both ends of the rack. The passenger side leaked clean fluid no problem its an easy fix and cost a few dollars with new seals but the driver side spewed out muddy looking rusty fluid and I'm pretty sure that side isn't easy to fix at all. Rack off jobbie I think. Anyone Fix the drivers side end seal? My luck has to change .............

So the local suppier didn't have the correct part. Lucky the next day I the DHL tracking number for the one I ordered about 10 days ago, it arrived today. They also sent me email answers to my questions but after they shipped it, lol. The item I received looks very well made and heavy construction. I guess the 8 dollars more for the Original part instead of the copy part was worth it. Now I need to find time to get it fitted. .......

This may help. Pm sent .....

Lift up the driver side carpet check the wiring harness bundle for broken, corroded wires and bad joints both soldered and crimped. If the carpet is wet you will need to find the culprit for that as well to prevent further issues. Sunroof channel holes front left and right alway block on mine with sand from Desert climate but also evaporator drain can block and drip AC water into foot well. Loads of threads about this ...........

How does the car run on the left pump only? Remove fuse from right pump and cycle ignition off and back on. If the car runs good on left pump but bad on right pump, you can almost guarantee the right pump, inside tank piping issue, or power to the right pump is the issue. You could also swap the fuses and relays to rule out that as a problem.

Thanks Brett. I replied in the other thread, but in case anyone reads this both evaporator don't work so this points to a common fault, so thanks to Brett's previous posts from his experience, I have ordered the compressor control valve. Unfortunately the seller still hasn't been in contact and I've run out of patience, tonight I will pick up one from a shop I found here in dubai after some sweaty searching this morning. It's blatantly Chinese copy part but at this point I need a solution so worth the risk. I will be trying to get paypal to refund the other one which didn't arrive. I will update hopefully tomorrow with the results.

Thanks Brett your reply. As you mentioned in the other thread if the expansion valve was blocked then the rear would also need to be blocked as they both blow hot. This seemed to me unlikely or a really big coincidence, so I looked for a common fault which could only be something before the expansion valves which is the compressor, drier blocked, the condenser blocked or a crushed pipe. Now if the system was blocked the high side would likely pressure up way too high and its not really that high even with 45oC ambient temps. So like you I diagnosed/educated guess if you will, the CCV. This looks like no flow! Unfortunately I order the part but the Gogoal company aren't responding and there is no telephone numbers. I sent the few emails and also contacted them via paypal but no reply. I'm wondering if this order will be fulfilled. Today I'm going to drop into a parts shop which apparently has all car AC parts Spares and see if they got a CCV, time is the factor, I need to get this fixed and get the car sold. Thanks again Brett.

Tombelgium Loren has given the low pressure fuel pumps flow here just in case there was any confusion. Of course the low pressure pumps flow must be within spec or the hpfp cant do its job. As you see 4 bar at rest in the fuel line this confirms the pressure of the low pressure fuel pump (at least one of them anyway) is good and within spec. Once you rule out the low pressure side it only really leaves the hpfp and injectors as possibles I think.

Mike, If your going to have the engine dropped for the seal make sure you got some metal coolant T's made up and replace those rubbish plastic ones. Also do the engine crankshaft seal like I did, its right there and god would you be pissed if later on the engine started leaking out the bell housing. Safe trip.

I doubt anyone here will put there neck on the line to definitely confirm but from what I read 90% the hpfp is faulty. Your story seems the same as other who have had the same issues but been in denial for a while that it needs replacement, even some pumps that had only been on the car for 4000km failed. I don't know how how else you can test for the failure yourself, bench testing is ideal but who has that setup in there house? Porsche have exchange units and may give some good will if you plead nicely.

I just took a gamble and bought a 50 dollar compressor control valve, I had some PayPal funds left from about 6 yrs ago I forgot about. It's listed as an original part (as opposed to the dirt cheap "non-original" 42 dollar part, thought I would lavish the old girl with 8 dollars extra wink lol) to fit compressor 7SEU17C which is the same as the 95812601400 denso unit fitted according to the receipt in 2011 when previous owner had Porsche in qatar put a new one in. Hope this works, even though they don't list Porsche Cayenne at all or VW Touareg! Fingers crossed this is going to be the ticket.

Hi Brett, some good knowledge in this thread, was hoping you might be able to offer some advice for me pls. Fyi I did start a new thread on this.... I got a ctt 2006 with 4 zone AC, the AC was working but never was great, after being in the gagrage and coming out and back in again the AC stopped working, no idea what the shop did but another garage only pulled 170grams from the system and then wasn't able to regas it, he said the low side was blocked. I replaced both high and low side AC service valvea as they was damaged and the vaccum and regas 1100grams went well. But the AC won't blow cool at all, in fact it hot ambient air. Ac compressor is on and climate controller seems to be working just fine. No codes, output tests all passed, vagcom vcds all checks out ok, compressor amps 0.8 @ 84% load. Test Gauges say 100psi on low side (too high) and 200psi on high side(a bit low). The garage tech said expansion valve is blocked he thinks. I'm reading also the compressor control valve could be at fault. If the CCV was not working wouldn't there be no real increase in high side pressure compared to the low side? Any help and advice appreciated. Also struggling to determine which CCV fits this compressor there seem to be a few variations. Thanks

Further research points towards the RCV inside the compressor is faulty. Refrigerant_Control_Valves.pdf

Yes this is the expansion valve, which possibly is blocked on my car. But what I replaced was the AC service valves which are used to check and refill the gas only.

Did some diagnostic using the vagcom vcds which was quite comprehensive in this hvac module. Only code was for low Gas, this was from before and resetting that code didn't magically Fix the issue unfortunately. No codes reappeared. As you can see the compressor is on and working, evaporator temp is basically the ambient temperature 39oC meaning it isn't getting a cold refrigerant through it at all. I went into advanced measuring blocks and done a full test. Everything worked perfectly flaps, blower, compressor etc. Flicked the economy button (which just turns the compressor off just like if you accelerate hard it kicks off to give max power) many times to try and kick the system into life but no luck. I've looked everywhere to find more info about replacing cleaning or serving the expansion valve and or evaporator but found nothing. There must be someone out there who has some tech info pls?

Hi Mike. Yep I meant the driveline is OK. The hesitation is still there and I'm considering if I will have the injectors cleaned or not. I ruled out a damaged low side pipe because when I first got the car back the AC worked but made a lot of noise under the dash evaporator/ expansion valve area and the AC would kick off as well then back on. I thought ok must be underfilled. The driveline was vibrating as well so I sent the car back to them. After a week I went to visit the garage and test drove it, AC felt better and vibration was gone, but air suspension fault wouldn't Clear and a knock was heard at the front strut area, so I asked them to recheck everything. After another week and the day before I went on vacation I picked up the car in a rush. The AC didn't work at all!!! I got pissed off and just left to get home asap, on the way it was 51oC inside the car I had to stop in a garage to try and get the AC looked at, they recovered just 175g from what should have been 1100g so I thought yeah it's undercharged and maybe leaking. Vacuum test was good, then he tried to regas the system but it wouldn't allow him, so he told me the low side is blocked or the AC service valve is damaged (which it was hence I replaced both yesterday). I drove home without AC and went on vacation for 3 weeks. Yesterday after AC service valve replacement, it re-gassed fine and high side was a good reading meaning compressor is on and working ok, low side was up in the 60's I think when ideal is between 25-40. I wonder if being open for a length of time in the dusty dirty gagrage the AC components got some dirt inside and it worked it's way to the evaporator/ expansion valve hence the noises I heard the first time I got the car back? Not sure what to do now, not looking forward to another garage disaster and bill. I read some people using high pressure solvent to access and blast out inaccessible system components and then vacuum the system out for like 1 hrs before regassing, in an attempt to avoid ripping apart the dash etc. Any advice? Anyone been through this?

Today I took the Cayenne 06 TT with 4 zone climate control to a shop to replace the damaged AC service valves and vacuum then regas the system to spec 1050-1100grams with 10g pag oil. See image of new valves for low (right side)and high side (left side), as you can see they are vw parts and they pretty much fit any vw model and Porsche Cayenne and probably a whole load of other brands as the valves are generic for a lot of manufacturers and fit AC equipments which are standardise for obvious reasons. I went to Porsche and they didn't have any stock so went to vw and they had plenty. Move the power steering reservoir out the way for easier access. Second picture. The old low side valve (image 3) with manky looking chewed up Rubber valve which was stopping regassing according to the shop I tried 4 weeks ago after collecting from the garage who did the torque convertor seal job and left me with no AC working but before when I collected it (then had to return it due to massive vibration and a list of other crap), it did work which is strange but undercharged is all; (51oC when I collected it the second time with Jack all AC working thanks a bunch guys)! So getting to the issue. . ...... Vacuum was fine no leaks, re-gassed to 1100 perfect, started car and ran AC, nothing but hot air. Gauge for high side was perfect in the green zone, but low side was much to high above the green zone and in the red. The technician concluded the compressor was good but the low side is blocked. He said the expansion valve is likely blocked and thus the low side is high. Makes sense. So a few questions pls... Q1. Is there any way a fault code or switch device/ sensor or valve located after the compressor could be off or shut and not allowing the refrigerant to not flow around to the condenser then onto the expansion valve and through the evaporator? Q2. How to get the expansion valve out, any diy pls, I searched and found nothing. Q3. Is there any other possibilities to consider? Appreciate responders. Thanks

Hi guys it's been a while... drove the cayenne today to get AC sorted out but not good news, will start a new thread for that in a minute. Regarding the torque convertor seal and other associated issues after the repair was done, I'm happy to say it drives ok and doesn't leak now from anywhere. Unfortunately as a result of the garages repairs or just by real bad luck the bonnet strut is broke and the AC is not working, the low side is blocked according to the diagnosis today. See new thread for more details and request for some info from you kind gents.

The regulator is supposed to hold 3 bar after 10 minutes. After that the manual I don't think specifies a drop but needless to say it won't hold for ever. I don't think the regulator was the problem as you confirmed after changing it didnt improve. Sounds more likely related to temperature sensor or vacuum leak which more likely. Smoke test your intake using the map senosr hole and bag off the pipes from the air boxes to seal up the system to retain the smoke. Search here I posted picture when I did mine.

Yep.

Check the earth strap from battery to the chassis in front of the drivers seat. High resistance or corrosion causing high resistance in that cable can cause no starts, the cable may feel warm when the car is running also. Check the positive cable as well! When you use a spare battery for jumping you by pass that cables high resistance to an extent. Another possible common issue is temperature sensor or crank shaft position sensor fault(seen a lot on other vw models). The other alternatives is a long list of wiring and components which could be failing under high heat conditions. Good luck with your search hope you find it.

Up to 2006 all models used only in tank primary and secondary pumps. Later models have the hpfp located at the back of bank 2. Yours is 2005 turbo I believe so you won't have hpfp. Your set up will therefore be exactly the same as the you tube video posted above.

All the same yes.